T874 Multistage Thermostats and Q674 Subbases PRODUCT DATA FEATURES • T874 Thermostat has silent, dust-free mercury switches operated by coiled bimetal elements. • Heat anticipator(s) are adjustable or fixed cooling anticipator(s) are fixed. • Individual heat and cool levers and scales (most models) for temperature setting located on top of thermostat case. • Cover thermometer on most T874 Multistage Thermostat models. • Locking cover and locking lever screws available for T874 Multistage Thermostats.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SPECIFICATIONS Tradeline Models IMPORTANT The specifications given in this publication do not include normal manufacturing tolerances. Therefore, this unit may not exactly match the listed specifications. This product is tested and calibrated under closely controlled conditions, and some minor differences in performance can be expected if those conditions are changed. T874 THERMOSTAT • T874 TRADELINE models provide staged heat and/or cool operation.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Standard Models Thermometer Range: 42° to 88°F (6 to 31°C) T874 THERMOSTATS Changeover Differential: 4°F (2°C) minimum between heating and cooling (5°F [3°C] on T874W). Levers can be set apart for greater separation. Models: See Table 3. Interstage Differential: Standard Models: Mechanical differential is 1°F (0.6°C) between heating or cooling stages; operating differential is approximately 1.9°F (1°C) between stages in heating or cooling.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Key Lock Cover: Part no. TG504A replaces existing T874 cover. Mounts on T874 base and covers thermostat settling levers and subbase switches. Includes LED window and two keys. Should not be used with 193121A Adapter Plate. — — TG504A1025: Blank face, internal thermometer. TG504A1033: External thermometer. See Fig. 2.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES — Fast cycling. T874G—Heat pump, cool changeover, with fast cycling. 0.120.6A 0.120.6A 0-1.0Ac 0.1-1.2A Electric Heat T872G Heat Pump or Standard 2 1 1b — Fixed anticipator for H2. — 0.1-1.5A — Fast cycling. T874H—Use with Q674C. 0-1.0A 0.120.6A T872H Heat Pump or Standard 1 1 1b 0-1.0Ac — 0-1.0A — T874J—Heat pump. None Heat Pump 2 1 2d 0-1.0Ae 0-1.5Ac 0-1.0Ac — T874K—Heat pump. None Heat Pump 2 1 1b 0.1-1.2A 0-1.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Q674E—Standard and TRADELINE. Q672E Standard OFF-HEAT-AUTOCOOL AUTO-ON T874A-D Q674F—Two LED models. — EM.HT. light. Q672F Heat Pump OFF-EM.HT.-HEATAUTO-COOL AUTO-ON T874C,D,G,N,S OFF-COOL-AUTOHEAT-EM.HT. AUTO-ON — Provision for AUTO fan operation in EM.HT. Q674G—O and B terminals. Q672G Standard OFF-AUTO None T874A-F Q674J—Provision for AUTO fan operation Q672J Heat Pump EM.HT.-AUTO-OFF AUTO-ON T874A,D,G,J in EM.HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES MERCURY NOTICE This control contains mercury in a sealed tube. Do not place control in the trash at the end of its useful life. If this control is replacing a control that contains mercury in a sealed tube, do not place your old control in the trash. Contact your local waste management authority for instructions regarding recycling and the proper disposal of this control, or of an old control containing mercury in a sealed tube.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES All wiring must comply with local electrical codes and ordinances. WALL IMPORTANT Use 18 gauge, solid-conductor wire whenever possible. If using 18 gauge stranded wire, no more than 10 wires can be used. Do not use larger than 18 gauge wire. WIRES THROUGH WALL OPENING WALL ANCHORS (2) M926 Follow equipment manufacturer wiring instructions when available. To wire subbase, proceed as follows: 1.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES JUMPER WIRE (SUPPLIED WITH SOME MODELS) 1 1 1 TWO ADJACENT TERMINALS SHOWN JUMPERED ARE FOR EXAMPLE ONLY. COMPARE WIRING DIAGRAM AND SUBBASE TO IDENTIFY TERMINALS TO BE JUMPERED. M5899 Fig. 8. Jumper adjacent terminals for special system hookup using stripped wire 3/4 in. (19 mm). For nonadjacent terminals and using jumper wire supplied with subbase. Table 5.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 5. Terminal Designationsa Standard Terminal Designation Alternate Designations or Customer Specials Typical Connection T External temperature readout, T relay R1, R2 Y a b LO and HI speed fan relays RS Cooling contactor M Compressor contactor Other terminal designations can be used that are not listed on this table. Refer to the hookup drawing and internal schematic for exact connections.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES 8. 9. 10. 11. Move the HEAT and COOL levers to the maximum temperature desired. Slide the stop brackets until one rests against the HEAT lever and the other against the COOL lever. Firmly tighten the mounting screw. If the HEAT and COOL levers are to be locked in place at a specific temperature, use the two insulated head screws supplied instead of the two adjustable lever stop brackets. ALLEN RETAINING SCREWS (2) CAUTION Equipment Damage Hazard.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Most heat pump systems should cycle 2-1/2 to 3 times per hour. Hang the upper edge of the thermostat cover on top of the thermostat base and swing the cover downward until it engages with the cover clip. STAGE ONE ANTICIPATOR HEATING CONTROL .1 2. 10 1.2 .8.6 .5 .4 .3 .2 .15 .12 4. .1 5 .2 .3 1.2 .8 .6 .4 STAGE TWO ANTICIPATOR HEATING CONTROL MOVE INDICATOR TO MATCH CURRENT RATING OF PRIMARY CONTROL M5069 Fig. 11.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES smaller differential. In cooling, slide the lever closer together for a larger differential, or wider apart for a smaller differential. While supporting the scale with hand, tighten the tension screw. IMPORTANT Support the scale with hand while tightening tension screw. See Fig. 13. Failure to do so can result in twisting and damaging bimetal coil. HEATING SETPOINT LEVER TENSION SCREW HEAT 50 60 70 80 CAUTION Equipment Damage Hazard.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Thermometer Move the system switch on the Q674 Subbase to COOL or AUTO. Move the cool setting lever on the T874 Multistage Thermostat about 10°F (6°C) below room temperature. See Fig. 12. The cooling equipment and fan should start. If the system has two stages of cooling, both stages should start. Move the cool lever about 10°F (6°C) above room temperature. The cooling equipment and fan should stop.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES thermostats. The schematics can be field-modified as required (EX: if T874C is being used, eliminate second stage of heat). For heat pump circuits: Cool changeover valve—operates on cooling. The reversing valve or relay is activated either by moving the system switch to COOL (manual changeover) or by a mercury switch that makes on a temperature rise (auto changeover). Heat changeover valve—operates on heating.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS (HOT) L1 L2 1 H1/C1 ANTICIPATOR R 2 FALL ODT 1 H1 RTD 1 C1 EHR 1 RTD 2 W3 3 4 FAN SWITCH ODT 2 AUTO EHR 2 ON H2 ANTICIPATOR W2 5 H2 RTD 3 RTD 1 AUX. HT. LED (GREEN) 6 2 FALL X EM. HT. LED (RED) SYSTEM SWITCH SYSTEM MONITOR RD L FAN RELAY G EM. HT. O HEAT OFF COOL CHANGEOVER VALVE E COOL EM. HT. RELAY CHP LACO Y B 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT L1 (HOT) R H1/C1 ANTICIPATOR FALL SYSTEM COMPONENTS ODT 1 L2 2 1 RTD 1 FAN SWITCH H1 C1 EHR 1 RTD 2 W3 3 AUTO 4 ODT 2 ON EHR 2 W2 H2 ANTICIPATOR 5 6 X EM. HT. LED (RED) H2 FALL SYSTEM SWITCH RTD 3 RTD 1 AUX. HT. LED (GREEN) SYSTEM MONITOR RD L FAN RELAY G EM. HT. O HEAT OFF EM. HT. RELAY CHANGEOVER VALVE E COOL 1 CHP LACO POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS H1/ C1 ANTICIPATOR FALL L1 (HOT) R 2 ODT 1 L2 1 H1 C1 3 RTD 1 FAN SWITCH EHR 1 RTD 2 W3 4 AUTO ODT 2 ON H2 ANTICIPATOR AUX. HT. LED (GREEN) 6 H2 EHR 2 W2 5 RTD 3 RTD 1 X FALL EM. HT. LED (RED) SYSTEM SWITCH SYSTEM MONITOR RD L FAN RELAY G EM. HT. O HEAT OFF 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) R H1/C1 ANTICIPATOR ODT 1 1 RTD 1 FAN SWITCH H1 L2 2 FALL C1 EHR 1 RTD 2 W3 3 AUTO 4 ODT 2 ON AUX. HT. LED (GREEN) 5 FALL RTD 3 RTD 1 X 6 H2 EHR 2 W2 H2 ANTICIPATOR EM. HT. LED (RED) SYSTEM SWITCH SYSTEM MONITOR RD L FAN RELAY G EM. HT. O HEAT OFF 1 EM. HT. RELAY CHANGEOVER VALVE E COOL POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) R H1/C1 ANTICIPATOR ODT 1 FALL 1 RTD 1 FAN SWITCH H1 L2 2 C1 EHR 1 RTD 2 W3 3 AUTO 4 ODT 2 ON AUX. HT. LED (GREEN) 5 FALL RTD 3 RTD 1 X 6 H2 EHR 2 W2 H2 ANTICIPATOR EM. HT. LED (RED) SYSTEM SWITCH SYSTEM MONITOR RD L FAN RELAY G EM. HT. O HEAT 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. OFF EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES OPERATION Heat anticipators add heat during the call for heat. Cooling anticipators are activated while the air conditioner is off. See Fig. 28. This heater makes the thermostat think it is warmer than it really is, and brings it on sooner than the bimetal alone would.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES CAUTION Equipment Damage Hazard. Due to calibration techniques used for T874 Thermostats with outdoor reset, the C815A Thermistor must be wired into the system at all times. Failure to do so will result in serious degradation of performance. Service and Replacement of C815A Outdoor Thermistor THERMISTOR RESISTANCE (ohms) To check and verify thermistor operation, perform the following steps: 1. Disconnect wire from T terminal on subbase. 2.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES When enthalpy is low enough, the thermostat and a sensor tell the economizer damper to open to let in cool air from the outside. When enthalpy is high, the thermostat and sensor tell the damper to close. No more outside air comes in, so the air conditioner is used instead. Heat Pump Application OFF EM. HT. HEAT AUTO COOL M5828 Fig. 31. System switching for automatic changeover.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES one controlling the auxiliary heat) makes only when the heat pump alone cannot handle the load. That is how the strategy of using the most economical heat first is implemented. Cycling Rate Normally, thermostat anticipation is set to cycle a fossil fuel furnace about five or six times an hour (at 50 percent load). This provides a reasonable balance between comfort, stability and economy.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Low Temperature Lockouts Some manufacturers of heat pumps have previously controlled their units so the compressor was locked out below a specified outdoor temperature. This was done because of the stress placed on the compressor by the very cold temperatures, and the fact that efficiency drops off at low temperatures.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Defrost Control In some regions, during half or more of the heating season, the outdoor coil operates below 32°F (0°C) Frost or ice builds up on the outdoor coil of a heat pump similarly to the frost buildup in a household refrigerator. Eventually, this accumulation of ice interferes with efficient heat transfer from the outdoor air to the coil and refrigerant.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES The disadvantage of this system is that it can require several outdoor thermostats. Also, since the unit is operating most often at nearly full capacity, the thermostat is on longer which results in more droop, with a little more offset from the thermostat setpoint.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES the thermostat. A set of contacts on the emergency heat relay is used to bypass each outdoor thermostat so that all electric heat is under immediate thermostat stage-two control. So the emergency heat relay simply bypasses the outdoor thermostats. See Fig. 41. In the second method, the emergency heat relay is cycled directly by the thermostat mercury bulb. In this hookup, the relay is controlled by the thermostat first stage.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES CROSS REFERENCE 3. The following section lists the current T874 Trade replacements for T872 and T874 Multistage Thermostats. It also lists the Q674 Trade replacements for Q672 and Q674 Subbases. 4. 5. 6. All thermostats listed carry the Honeywell logo unless otherwise noted. When using the Cross Reference Charts, refer to the following instructions: 1. Locate and identify the existing thermostat and subbase model. 2.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 6. T872-T874 Thermostat Cross Reference. Model Number Remarks A1279 General Electric logo; no. AY28X114A; 75°F stop; T874A1010 locking cover; no thermometer. Use T874A1176 for Dept. of Defense (DoD) application. A1287 T874A1036/ General Electric; no. AY28X097A; fan current shunt for auto fan in heating; heat anticipator set at Q674B1018 0.4A. Set thermostat stage 1 heat anticipator for total of fan and stage 1 primary control current draw.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 6. T872-T874 Thermostat Cross Reference. Model Number a T874 Trade Replacementa Description C1103 Amana logo; anticipator set at 1.2A T874C1018 C1111 Airtemp (Chrysler) logo T874C1018 C1129 Day and Night logo; no. 0.1-0.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 6. T872-T874 Thermostat Cross Reference. Model Number T874 Trade Replacementa Description C1509 Fedders logo; used with Q672L1102 Y594R1425 Wiring differences (old=new): C=X, K=E; remove Y-W1 jumper. C1517 Climatrol logo; used with Q672L1102 Y594R1425 Wiring differences (old=new): C=X, K=E; remove Y-W1 jumper. C1525 Square D logo; no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 6. T872-T874 Thermostat Cross Reference. Model Number D1144 Carrier logo; no. HH07AT072 T874D1165 D1151 General Electric logo; no. AY28X098; 0.4 heat anticipator setting T874D1165 D1169 Airtemp (Chrysler) logo; used with Q672E1118 T874D1165/ Q674E1049 D1177 Trane logo T874D1165 D1185 Dunham-Bush logo T874D1165 D1193 Fedders logo T874D1165 D1201 Climatrol logo T874D1165 D1219 Command-Aire logo T874D1165 D1227 Singer logo; no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 6. T872-T874 Thermostat Cross Reference. Model Number E1036 American Standard logo T874E1016 E1044 York logo; locking cover T874E1016 E1051 ITT logo T874E1016 E1069 Climatrol logo T874E1016 E1077 Airtemp (Chrysler) logo T874E1016 E1085 Lennox logo T874E1016 E1093 Trane logo T874E1016 E1101 Dunham-Bush logo T874E1016 E1119 Fedders logo T874E1016 E1127 Climatrol logo T874E1016 E1135 General Electric logo; no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 6. T872-T874 Thermostat Cross Reference. Model Number a T874 Trade Replacementa Description Remarks G1026 Lennox logo; fast cycle performance; stage 2 heat; None fixed anticipator stage 1 heat and cool; changeover with cooling; used with Q672E1019, F1067. See subbase description for replacement information.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 6. T872-T874 Thermostat Cross Reference. Model Number T874 Trade Replacementa Description G1208 Marvair logo; special for Crispaire; used with Q672F1166, F1323. Y594G1393 G1216 Janitrol logo; no. 26G05; stage 2 heat anticipator set at 1.2A; used with Q672F1117. Y594G1252 G1224 TRADELINE; adjustable anticipator stage 2 heat; fixed anticipator stage 1 heat and cool; changeover in cool; used with Q672F1208.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 6. T872-T874 Thermostat Cross Reference. Model Number N1010 Williamson logo; adjustable anticipator stage 1 and T874N1016/ Q674F1220 2 heat; fixed anticipator stage 1 cool; used with Q672F1133 or F1315. N1028 TRADELINE heat mode changeover; used with Q672F1216. T874N1016 N1036 Bard; used with Q672F1299. T874N1016/ Q674F1220 N1044 Thermotron logo; 1st stage changeover heat mode; used with Q672F1299.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 6. T872-T874 Thermostat Cross Reference. Model Number Remarks R1123 York logo; no. 025-21453C; Celsius scale. R1131 Lennox logo; separate auxiliary heat power circuit; None fast cycle stage 2 heat anticipator; outdoor reset; used with Q672L1144, C815A1013. R1149 Westinghouse logo; adjustable stage 2 heat anticipator; cooling changeover; fixed anticipator stage 1 heat and cool; used with Q672L1110, L1128, L1151.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 7. Q672-Q674 Subbase Cross Reference. Model Number Q672A A1005 Q674 Trade Replacementa Description System: HEAT-AUTO-COOL, Fan: AUTO-ON Standard OEM Q674A1019 A1013 TRADELINE Q674A1019 A1021 RC-RH jumper Q674A1019 RC-RH jumper required. RC-RH jumper; Chek Lite Q674A1019 RC-RH jumper required. A1039 Q672B System: HEAT-OFF-COOL, Fan: AUTO-ON B1004 Standard OEM Q674B1034 B1012 Isolated G terminal.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 7. Q672-Q674 Subbase Cross Reference. Model Number Q674 Trade Replacementa Description B1269 Whalen; Hi-Lo fan switch; constant fan in heat and cool system switch positions; used with T872C1574. None B1277 Square D no. HCB-5. Q674B1034 B1285 Wards; RC-RH and F-W3 jumpers; used with T872C1673. Gas Furnace: T874C1018/ Q674B1034 Electric Furnace: T874C1018/ Q674B1075 B1293 Q672C Adjust anticipator faster for correct performance.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 7. Q672-Q674 Subbase Cross Reference. Model Number Remarks E1050 TRADELINE Q674E1049 E1068 RC-RH jumper; used with T872C1699. Q674E1049 RC-RH jumper required. E1076 RC-RH internal jumper; EM. HT. LED. Q674E1049 RC-RH jumper required. E1084 Carrier no. HH93AZ076; RC-RH jumper. Q674E1049 RC-RH jumper required. E1092 Carrier no. HH93AZ082; RC-RH jumper; B terminal; isolated G terminal. Q674E1049 E1100 General Electric no. AY28X099.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 7. Q672-Q674 Subbase Cross Reference. Model Number F1125 BDP no. 3442DP90; used with T872G1117, G1166, G1174. Y594G1252 F1133 Williamson; heat pump; EM. HT. LED; heat mode changeover; compressor lockout in EM. HT.; used with T872N1010. T874N1016/ Q674F1220 F1141 Westinghouse; EM. HT. LED; auto fan in EM. HT.; used with T872G1034. Y594G1252 F1158 Rheem Ruud; heat pump; EM. HT. LED; cool Y594G1252 mode changeover; compressor lockout in EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 7. Q672-Q674 Subbase Cross Reference. Model Number G1074 Singer no. 02005754; X1 and X2 terminals for field-added indicator lights; used with T872D1375. None G1082 Singer no. 02005792; X1 and X2 terminals for field-added indicator lights; used with T872D1375. None G1090 TRADELINE; B and O terminals. Q674G1070 Q672H H1008 Q672J Used with T872. None System: EM. HT.-AUTO-OFF Fan: AUTO-ON. With EM. HT. LED; used with T872C or D.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 7. Q672-Q674 Subbase Cross Reference. Model Number a Q674 Trade Replacementa Description Remarks L1052 Carrier no. HH93AZ075; heat pump; EM. HT. LED; cool mode changeover; compressor lockout in EM. HT.; used with T872G1075, G1182, G1273, G1307. Y594R1615 L1060 Dunham Bush; EM. HT. LED; used with T872R1099. Y594R1243 L1078 Tappan no. B13708-58; heat pump; EM. HT. LED; cool mode changeover; compressor lockout in EM. HT.; EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 7. Q672-Q674 Subbase Cross Reference. Model Number L1342 Lennox no. 52C7601; used with T872W1019 and C815A1013. None L1375 Westinghouse; used with T872R1271, W89. None L1383 Dunham Bush; used with T872R1099. Y594R1243 L1391 Williamson; used with T872R1339. Y594R1243 L1409 Duotherm special; used with T872R1321, W89.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. T874A A1002 Remarks 1-stage heat, 1-stage cool. 44, 65 Honeywell logo; Standard OEM; used with Q674B1331. T874A1036 A1010 44 Honeywell logo; includes Allen wrench and screws to lock cover; non-adjustable range stops set at 72°F (max. heat) and 78°F (min. cool) (22-26°C); field adjustable locking levers. T874A1010 A1028 44 Honeywell logo; heat anticipator factory set at 0.4A.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number A1200 Fig. No. Trade Model Replacement Description 51, 53 Obsolete. Carrier logo; part no. HH07AT164; °C scaleplate; includes Allen wrench and screws to lock cover; used with Q674B. T874A1036 a Remarks Set stage 1 heat anticipator for total current draw of fan and stage 1 heat primary; replacement has °F scaleplate.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. A1481 44 Obsolete. Honeywell logo; Carrier part no. HH621602; includes locking cover and non-adjustable range stops set at 72°F (max. heat) and 78°F (min. cool). T874A1036 A1507 44 Obsolete. Climate-Tel logo; includes Allen wrench and screws to lock cover and non-adjustable range stops set at 72°F (max. heat) and 78°F (min. cool). T874A1176 A1523 224, 225 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. B1134 222 T874C Obsolete. Carrier Synergy 2000 logo; part no. HH07AT199; °C scaleplate; used with Q674E1395 (HH93AZ209). T874B1019/ Q674E1049a Remarks Wiring differences (old=new): W1=W; RC-RH jumper required; replacement has no LEDs. 2-stage heat, 1-stage cool. C1000 44, 76 Honeywell logo; used with Q674B1075, C1181; used in Y594C1058.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Trade Model Replacement Description Remarks C1216 44 Obsolete. Fasco part no. 1230-8197. T874C1018 C1224 105 Obsolete. Square D logo. T874C1018 C1240 44 Honeywell logo; Honeywell Canada TRADELINE model; °C scaleplate; includes Allen wrench and screws to lock cover. T874C1018 Replacement has °F scaleplate. C1257 44 Obsolete. Singer part no. 0200-5931; 8°F (4.4°C) differential between H1 and H2 heat.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. C1489 121 Obsolete. Honeywell logo; non-adjustable range stops set at 75°F (max. heat and min. cool) (24°C); used with Q674L1157. Y594C1322 C1497 121 Obsolete. Honeywell logo; meets DoD specifications; used with Q674L1157. Y594C1322a C1513 44 Obsolete. Borg-Warner multi-logo; part no. 6TH11703124A. T874C1018 C1562 44 Obsolete. Honeywell logo; Heil Quaker part no. HQ712001HW.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. C1877 53 T874D Trade Model Replacement Description Obsolete. Honeywell logo; TRADELINE model; used with Q674B1554; used in Y594C1421. Y594D1347 166, 82 Obsolete. Honeywell logo; used with Q674F1337, E1007; used in Y594D1222, D1339. T874D1165 D1017 44, 88 Obsolete. Honeywell logo; TRADELINE model; includes Allen wrench and screws to lock cover; used with Q674A-G and Q674E1155.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. D1215 44 Obsolete. Friedrich Climate Master logo; part no. AT5415; °F/°C scaleplate. T874D1165 Replacement has °F scaleplate. D1223 44 Honeywell logo; Honeywell Canada TRADELINE model; Celsius scale. T874D1165 Replacement has °F scaleplate. D1231 44 Obsolete. Honeywell logo; 12°F (7°C) differential between H1 and H2. T874D1165 Replacement has 2°F differential between H1 and H2.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. a Model Number Fig. No. Trade Model Replacement D1470 44 Obsolete. York logo; part no. 2TH04701624A; includes Allen wrench and screws to lock cover; °C scaleplate. T874D1165 Description D1488 44 Obsolete. Risco special. T874D1165 D1496 44 Obsolete. Borg Warner multi-logo; part no. 6TH04701524A; includes Allen wrench and screws to lock cover. T874D1165 D1504 82 York logo; part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number D1801 D1819 D1827 Fig. No. Trade Model Replacement Description 45, 208 Trol-A-Temp by Honeywell logo; H1 and H2 anticipators set at 0.10A; used with Q674B1463, D1115. 44 Marv Air Com Stat logo; part no. 50059; adjustable interstage between H1 and H2 and between C1 and C2; includes Allen wrench and screws to lock cover; field adjustable range stops; °F/°C scaleplate.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. D2056 44 Obsolete. ComStat logo; part no. 50056; °F/°C scaleplate; adjustable interstage on both heating and cooling; includes locking cover and field-adjustable locking levers. T874D1165 Replacement has °F scaleplate and 2°F fixed differential in heating and cooling. D2064 53 Obsolete. Carrier Weathermaker; part no. HH07AT209; stage 1 and 2 heat anticipator factory set 0.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. E1081 44 Trane logo; part no. BAY28X186; °F/°C scaleplate. T874E1016 Replacement has °F scaleplate. E1099 44 Obsolete. Lennox logo; part no. 13F1001; °C scaleplate. T874E1016 Replacement has °F scaleplate. E1107 44 Honeywell logo; °C scaleplate. T874E1016 Replacement has °F scaleplate. E1123 44 Obsolete. Amana logo; part no. D68535-4. T874E1016 E1149 44 Obsolete. York logo; part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. Trade Model Replacement Description Remarks G1014 86, 150 Obsolete. Lennox logo; part no. 24F5801; °F/°C scaleplate; H2 anticipator factory set at 0.25A for fast cycle performance; changeover in cooling mode; independent heating and cooling circuits; used with Q674E1148, F1113. Y594G1252 Wiring differences (old=new): R=O, M=Y, F=G, Y=W2, V-VR=R (must use single transformer). G1022 86, 150 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. G1204 162 Honeywell logo; designed for use on Trane heat pumps; no H2 anticipation; changeover in cooling mode; used with Q674J1043 and C815A1005; used in Y594G1161. Y594G1161 G1212 155 Obsolete. Honeywell logo; H2 anticipator factory set at 0.2A; changeover in cooling mode; includes shunt to bypass H2 anticipator with W3 heat relays; used with Q674F1238. Y594G1252a G1220 235 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. Trade Model Replacement G1444 160 Obsolete. ROCA logo; °C scaleplate; used with Q674J1027. G1451 155 Obsolete. BDP multi-logo; part no. HH641502; used with T874G1246a or Q674F1212; used in Y594G1245. V594G1252a G1469 194 Obsolete. No logo; Addison special; used with Q674F1345; used in Y594G1344. G1485 163 Obsolete. AAF logo; part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. G1659 177 Trade Model Replacement Description Obsolete. Mammoth logo; 0.8A maximum current through B or O terminal; 12°F differential between H1 and H2 for night setback; used with Q674C1330; used in Y594G1427. Y594H1012 a Remarks Wiring differences (old=new): R2=L, R1=none; L-R jumper required; no night setback. T8611G1004 Includes night setback. (programmable) G1675 174 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. G1873 160 Obsolete. Honeywell logo; TRADELINE model; Premier White® color; designed to replace Y594G1013 (York part no. 2TH11702424), Y594G1229 (York part no. 6TH11702424), and York part no. 2TH117704124); used with Q674J1225; used in Y594G1575. Y594G1567 G1881 167 Rheem; part no. 41-20797-18. Y594G1526a G1899 169 Obsolete. Amana; part no. 10574101; used with Q674F1550; used in Y594G1591.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. H1021 74 H1039 Remarks Obsolete. Friedrich Climate Master logo; part no. AT5821; °F/°C scaleplate; used with Q674C1041. a Y594H1012 Wiring differences (old=new): Y1=O, Y2=Y; L-R jumper required; replacement has °F scaleplate. 79 Obsolete. Mammoth logo; °F/°C scaleplate; used with Q674C1124; used in Y594H1004. Y594H1012a Wiring differences (old=new): R1=R, R2=L. H1054 74 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. J1069 124, 144, 206, 207 Obsolete. Honeywell logo; TRADELINE model; used with Q674J1282; used in Y594J1019. T8511G1021 J1077 124, 171 Obsolete. Nordyne logo; part no. 9148300; °F/°C scaleplate. T8511G1021 T874K Remarks Heat pump model; 2-stage heat, 1-stage cool, automatic changeover in heat. K1001 77 Obsolete. LSI Mammoth logo; used with Q674C1090.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. N1040 179 Obsolete. Honeywell logo; H1 and C1 anticipation fixed; used with Q674F1261; used in Y594N1015. None N1057 178 Obsolete. Intertherm logo; part no. 9111882; used with Q674F1220; used in Y594N1023. T874N1016 N1065 178 Obsolete. Miller logo; Nordyne part no. 9122240; used with Q674F1220; used in Y594N1031.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. a Model Number Fig. No. Trade Model Replacement R1079 123 Obsolete. Ruud logo; part no. UXMT-C70; used with Q674L1157. Y594R1243 R1087 120 Obsolete. Honeywell logo; Special for Dunham Bush; use with Q674L. Y594R1664a R1095 123 Obsolete. Rheem logo; part no. RXMT-C70; used with Q674L1157. T874R1152/ Y594R1243a R1103 104 Obsolete. Westinghouse logo; used with Q674L. Y594R1243a R1111 116, 104 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. R1319 191 Obsolete. Carrier part no. 42QH400083; used with Q674B1281 on two speed fan applications. See OEM for replacement. R1327 120 Obsolete. Borg-Warner multi-logo; part no. 6TH11702224A; used with Q674L1272; used in Y594R1193. Y594R1672a R1335 106 Obsolete. BDP multi-logo; part no. HH641501; H2 anticipator factory set 1.2A; used with Q674L1405; used in Y594R1201.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. a Model Number Fig. No. R1574 132 R1582 Trade Model Replacement Description Remarks Obsolete. Comfortmaker logo; part no. 1505739; used with Q674L1538; used in Y594R1383. a Y594R1243 Wiring differences (old=new): C=X, X=L, W=W2. 132 Obsolete. Arcoaire logo; part no. 150739; used with Q674L1538; used in Y594R1391. Y594R1243a Wiring differences (old=new): C=X, X=L, W=W2. R1590 115 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. R1889 120 Honeywell logo; designed to replace Y594R1151 (York part no. 2TH11702324), Y594R1193 (York part no. 6TH11702224), and York part no. 2TH11704024; used with Q674L1736 and C815A1054; used in Y594R1672. Y594R1672 R1897 230 Honeywell logo; Premier White® color; used with Q674L1751; used in Y594R1680. Y594R1680a R1905 120 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 8. T874 Cross Reference. Model Number Fig. No. T874W Trade Model Replacement Description Remarks 3-stage heat, 2-stage cool, manual changeover. W1007 118 Obsolete. Honeywell logo; Westinghouse special; used with Q674L1256. W1015 54 Honeywell logo; used with Q674B1216 and C815A1005; used in Y594W1014. T874W1015 W1023 233 Obsolete. Lennox Advanced Heat Pump System logo; used with Q674L1280 and W89.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. Q674A Q674 Trade Replacement Description Remarks System: HEAT-AUTO-COOL; Fan: AUTO-ON A1001 71 Standard OEM. Q674A1019 A1019 71 TRADELINE® model; used with T874A-D. Q674A1019 A1035 71 Obsolete. Trane part no. BAS-0435; used with T874A-D. Q674A1019 A1043 71 Honeywell logo; TRADELINE model; Q674A1019 A1050 71 Obsolete. Standard OEM.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. Q674 Trade Replacement B1240 234 Obsolete. Northrup heat pump; AUX HEAT LED; used with T874G1139. Y594G1252 Wiring differences (old=new): Y1=Y2, W1=W2; EM HT system switch position is not operational. B1257 56 Obsolete. LSI-Mammoth; RESET LED; automatic fan operation in heat and cool modes; used with T874C1471; used in Y594C1314. Q674B1075 Replacement has no LED. B1273 57 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. B1554 82 Obsolete. TRADELINE; includes LOCKOUT LED and removable jumpers between RC and RH terminals; used with T874C1877; used in Y594C1421. Y594D1347 B1562 45 Obsolete. Amana logo; part no. P1217701F; removable jumpers between RC and RH terminals. Q674B1034 B1570 45 Obsolete. Armstrong logo; part no. 03299A18. Q674B1034 Replacement is beige. B1588 45 Obsolete. Standard OEM.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. Q674 Trade Replacement C1207 78 Obsolete. Friedrich; System: OVERRIDE-AUTO-OFF; used with T874P1014. T8600D2028 Wiring differences (old=new): (programmable) L=R, W=O; W-Y jumper required; night setback. C1215 97 Obsolete. Friedrich part no. AQ5315; System: OVERRIDE-AUTO-OFF; OVERRIDE and SERVICE LEDs; used with T874P1022, P1030.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. Q674 Trade Replacement C1389 205, 176 Obsolete. Command Aire part no. P1099-0021; two LEDs; used with T874G-H. None See thermostat description for replacement information. C1397 205, 171 Obsolete. Command Aire part no. P1099-0023; used with T874G-H. None See thermostat description for replacement information. C1413 213 Obsolete. Carrier part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. D1065 63 Obsolete. Includes two LEDs; used with T874F1122. T874F1015/ Q674D1040a D1099 55, 66 Obsolete. Trane part no. BAS-0430; used with T874A-F. Q674D1040 D1107 55, 66 Obsolete. Snyder General part nos. 654958801/ 1520503/ 4ELN30070. Q674F1040. D1115 208 D1123 208 Trol-A-Temp; gray color; used with T874D1827. D1156 55 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. Remarks E1262 82 Lennox part no. 13F1701. Q674E1049 E1270 198 Obsolete. Carrier part no. HH93AZ189; used with T874L1000 (HH07AT176). Y594G1419a E-W2 jumper required. E1304 82 Obsolete. BDP part no. P272-1887; used with T874L1026. Y594G1419a E-W2 jumper required. E1312 224 Obsolete. McQuay part no. 60684901; one LED; used with T874A1523, A1549, D1686, D1918.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. a Model Number Fig. No. F1089 152 Q674 Trade Replacement Description Obsolete. Includes EM HEAT LED; X2-E and RC-RH jumpers. Remarks Q674F1022 F1097 142 Obsolete. Southwest special; W2-X2 jumper. Q674F1022 F1105 145 Obsolete. Lennox heat pump; EM HEAT LED; used with T874G1154. Y594G1252a Wiring differences (old=new): V=R, Y=W2, F=G, X2=X, R=O, M=Y; L-E jumper required. F1113 150 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. a Model Number Fig. No. Q674 Trade Replacement F1360 167 Obsolete. Rheem part no. 41-20797-17; AUX HEAT and EM HEAT LEDs; used with T874G1493. Y594G1526 F1378 195 Obsolete. Includes EM HEAT and AUX HEAT LEDs; used with T874G1501. Y594G1252a Wiring differences (old=new): L1=L; changeover in cooling only. F1394 139 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. F1675 248 Obsolete. WaterFurnace logo; part no. TA21H03; includes four LEDs. G1005 184 Obsolete. Used in Y594F1063. Q674G1070 G1013 186 Obsolete. Climate Control; used with T874D1298. See OEM for replacement. G1021 91 Obsolete. Includes O and B terminals; used with T874A-F,Q or T874D1082; used in Y594D1032. Q674G1070 G1047 92 Obsolete. Used with T874C1018, C1125.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. J1084 171 Obsolete. BDP heat pump; part no. 34427DP126, P272-1879; EM HEAT LED; used with T874J1010. Y594J1019 Wiring differences (old=new): W1=W2, F=L. J1118 196 Obsolete. Carrier heat pump; part no. HH93AZ188; SUPL HEAT LED; System: SUPL.HT.-ON-OFF; used with T874G1055 (HH07AT171). Y594G1674 Wiring differences (old=new): C=X;Y1=W1; jumper required; no auto fan in emergency heat.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. K1026 95 System: OFF-WOOD-WOOD/ OIL-OIL; used with T874F1155. Q674K1026 Remarks K1034 93 Obsolete. Snyder General part no. 4ELN-7920. Q674E1049 Fan switch is not operational. K1042 93 Obsolete. Carrier part no. HH93AZ172-W; gray color; includes removable jumper between RC and RH terminals. Q674E1049 Fan switch is not operational.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. a Model Number Fig. No. Q674 Trade Replacement L1199 114 Obsolete. Lennox no. 24F6001; used with T874D1207 T8611M2025 Wiring differences (old=new): and C815A1013. (programmable) V-VR=R, Y=W3, X=C, R=O, M=Y, M2=Y2-W2, F=G; jumper Y2-W2; no outdoor reset needed; use only one system transformer. L1207 115 Used with T874R1152, R1590, R1640, R1921; used in Y594R1243, R1706.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. a Model Number Fig. No. Q674 Trade Replacement L1405 106 Obsolete. BDP heat pump; part no. HH641501; used with T874R1335; used in Y594R1201. Y594R1243 L1413 133 Obsolete. Fedders heat pump; used with T874R1343; used in Y594R1219. Y594R1425a L1421 125 Obsolete. Coleman heat pump; used with T874R1368; used in Y594R1235. Y594R1797a L1439 131 Obsolete. Carrier part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. a Model Number Fig. No. Q674 Trade Replacement L1678 209 Trol-A-Temp by Honeywell; gray color; used with T874R1707; used in Y594R1490. None See Trol-A-Temp. L1686 209 Trol-A-Temp by Honeywell; used with T874R1715; used in Y594R1508. None See Trol-A-Temp. L1702 132 Obsolete. Snyder General heat pump; part no. 654958B07; used with T874R1723 and C815A1005; used in Y594R1516.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 9. Q674 Subbase Cross Reference. Model Number Fig. No. L1868 125 TRADELINE; includes two LEDs; used with T874R1988; used in Y594R1797; direct replacement for Evcon/Coleman Y594R1235 (T874R1368/ Q674L1421) Coleman part no. 3600-368. Y594R1797 L1876 245 Obsolete. Amana part no. 10573902; includes two LEDs; used with T874R2002; used in Y594R1805. Y594R1797 Wiring differences (old=new): C/X=X. L1884 245 Obsolete. Amana part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 10. Y594 Cross Reference. Model Number Fig. No. Trade Model Replacementa Description Remarks Y594A A1001 46 Obsolete. Amana part no. D68535-11; contains T874A1077, Q674B1075. T874A1036/ Q674B1075 A1019 82 Obsolete. Amana part no. P68535-12; contains T874A1077, Q674E1056. T874A1036/ Q674E1049 A1035 44 Obsolete. Trane part no. 268-0187-1; contains T874A1085, Q674B1018. T874A1036/ Q674B1018 A1043 46 Obsolete. Trane part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 10. Y594 Cross Reference. Model Number Fig. No. Trade Model Replacementa Description Remarks C1348 70 Obsolete. Fiberglas; contains T874C1653, Q674S1000. T874C1000/ Q674B1075 C1355 45 Obsolete. Nordyne “Miller” part no. 9122250; contains T874C1695, Q674B1000. T874C1018/ Q674B1034 C1363 45 Obsolete. Nordyne “Intertherm” part no. 911100001; contains T874C1703, Q674B1000. T874C1018/ Q674B1075 C1371 184 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 10. Y594 Cross Reference. Model Number Fig. No. Trade Model Replacementa Description Remarks D1347 82 TRADELINE® contains T874D1942, Q674E1403. Y594D1347 D1354 82 SUPER TRADELINE® contains T874D2031 (no cover), Q674E1049, and TG504A with two keys. Y594D1354 D1370 45 Obsolete. Carrier part no. 50QE90022101; contains T874D2049 and Q674B1539. T874D1165/ Q674B1034 Replacement has °F scaleplate. D1388 72 Obsolete. Carrier part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 10. Y594 Cross Reference. Model Number a Fig. No. Trade Model Replacementa Description Remarks G1294 79 Obsolete. LSI; contains T874G1378, Q674C1124. See OEM for replacement. H2 is night setback. G1328 194 Obsolete. Addison part no. 8403-197; contains T874G1543, Q674F1345. Y594G1252 Wiring differences (old=new): Y1=O, X=L, C=X. G1344 194 Obsolete. Heat Controller part no. 7601-110B; contains T874G1469, Q674F1345.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 10. Y594 Cross Reference. Model Number G1617 Fig. No. 73 Trade Model Replacementa Description Obsolete. Carrier part no. 50QE90020101; contains T874G1949 and Q674C1504. Y594H1012 a Remarks Wiring differences (old=new): Y1=O, Y2=Y, L=R, R=none; R-L jumper required; no night setback. T8600D2028 Wiring differences (old=new): (programmable) Y1=O, Y2=Y, L=R; W-Y jumper required; night setback. G1625 160 York Canada part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 10. Y594 Cross Reference. Trade Model Replacementa Model Number Fig. No. J1019 244 Obsolete. TRADELINE; automatic changeover; contains T874J1069 and Q674J1282; direct replacement for T874J1002 or T874J1028 used with Q674J1068 or Q674J1159 (HH07AT175 or HH07AT165 used with HH93AZ183 or HH93AZ196). (Recontrol) T8511G1021 N1007 178 Obsolete. Williamson part no. 75-189; contains T874N1008 and Q674F1196. T874N1016/ Q674F1196 N1015 179 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 10. Y594 Cross Reference. a Trade Model Replacementa Model Number Fig. No. R1292 108 Contains T874R1467 and Q674L1512; replaces Y594R1110 (T874R1137/Q674L1132). Y594R1292 R1300 123 Contains T874R1475 and Q674L1520. Y594R1300 R1318 130 Obsolete. Comfortmaker part no. 1505721; contains T874R1483, Q674L1538 and C815A1005. Y594R1763 R1326 137 Obsolete. SUPER TRADELINE; contains T874R1491 and Q674L1553. Y594R1615 R1334 47 Obsolete.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 10. Y594 Cross Reference. a Trade Model Replacementa Model Number Fig. No. R1615 230 TRADELINE; contains T874R1822 and Q674L1710; replaces Y594R1326 (T874R1491/ Q674L1553). Y594R1615 R1623 134 Obsolete. Rheem Universal Parts part no. 4120796-46; contains T874R1558 and Q674L1504. Y594R1300 R1631 134 Rheem part no. 41-20796-29; contains T874R1442 and Q674L1504. Y594R1300 R1649 134 Ruud part no.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES Table 10. Y594 Cross Reference. Trade Model Replacementa Model Number Fig. No. R1797 125 TRADELINE; contains T874R1988 and Q674L1868; direct replacement for Y594R1235 (T874R1368/Q674L1421) Evcon/Coleman part no. 3600-368). Y594R1797 R1805 245 Obsolete. Amana part no. 10636702; contains T874R2002 and Q674L1876. Y594R1797 Wiring differences (old=new): C/X=X. R1813 245 Obsolete. Amana part no. 10636704; contains T874R2010 and Q674L1884.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES WIRING DIAGRAMS SUBBASE THERMOSTAT SYSTEM COMPONENTS L1 (HOT) L2 1 RH HEAT RELAY 1 W1 1 FAN SWITCH H1 FALL HEAT RELAY 2 AUTO W2 H1 ANTICIPATOR HEAT CHANGEOVER VALVE ON H2 2 6 H2 ANTICIPATOR FALL SYSTEM SWITCH COOL CHANGEOVER VALVE O 8 FAN RELAY HEAT G C1 RISE NOTE: Model ing No.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE HEAT RELAY 1 W1 1 FAN SWITCH H1 FALL HEAT RELAY 2 AUTO W2 H1 ANTICIPATOR ON HEAT CHANGEOVER VALVE B 4 H2 L1 (HOT) L2 1 R 6 H2 ANTICIPATOR FALL SYSTEM SWITCH O COOL CHANGEOVER VALVE 8 HEAT C1 RISE OFF G 9 COOL FAN RELAY Y2 10 C1 ANTICIPATOR C2 ANTICIPATOR COMPRESSOR CONTACTOR 2 Y1 11 COMPRESSOR CONTACTOR 1 C2 RISE 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE L1 (HOT) L2 1 HEAT RELAY 1 W1 1 H1 FAN SWITCH FALL FAN RELAY G AUTO H1 ANTICIPATOR ON EXTERNAL FAN SWITCH 4 RC H2 H2 ANTICIPATOR FALL HEAT RELAY 2 6 W2 8 HEAT CHANGEOVER VALVE C1 RISE 9 B SYSTEM SWITCH L2 RH HEAT 10 OFF C1 ANTICIPATOR COOL C2 ANTICIPATOR RISE 2 X1 L1 (HOT) 1 FILTER LED (RED) O COOL CHANGEOVER VALVE 11 C2 Y1 COMPRESSOR CONTACTOR 1 1 2 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS H1 ANTICIPATOR HEAT RELAY 1 1 W1 H2 FAN SWITCH HEAT LED (RED) FALL AUTO BLOWER RELAY G 4 ON H2 ANTICIPATOR L1 (HOT) L2 1 R 6 HEAT RELAY 2 FALL H1 W2 SYSTEM SWITCH 8 C1 ANTICIPATOR HEAT 9 T OFF COOL LED (YELLOW) COOL C1 1 Y1 10 RISE COMPRESSOR CONTACTOR LO SPEED LED (GREEN) POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS HEAT RELAY 1 FALL W1 H1 1 H1 ANTICIPATOR FAN SWITCH FAN RELAY G 3 AUTO L1 (HOT) 1 L2 ON RC 4 2 HEAT RELAY 2 W2 6 FALL HEAT CHANGEOVER VALVE H2 ANTICIPATOR H2 B 8 3 SYSTEM SWITCH RH C1 HEAT RISE 9 COOL CHANGEOVER VALVE O OFF 3 COOL C1 ANTICIPATOR COMPRESSOR CONTACTOR 1 10 Y1 C2 ANTICIPATOR RISE COMPRESSOR CONTACTOR 2 11 Y2 C2 1 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SYSTEM COMPONENTS SUBBASE THERMOSTAT 1 H1 ANTICIPATOR HEAT RELAY 1 FAN SWITCH W1 AUTO FALL HEAT RELAY 2 H1 ON 4 W2 H2 6 FALL H2 ANTICIPATOR 8 L1 (HOT) R SYSTEM SWITCH L2 HEAT RISE C1 1 OFF 9 G COOL FAN RELAY 10 Y2 C1 ANTICIPATOR COMPRESSOR CONTACTOR 2 C2 ANTICIPATOR 11 Y1 C2 RISE 1 COMPRESSOR CONTACTOR 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M3202A Fig. 53.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES H1 L1 (HOT) L2 RH FALL 3 B 1 H1 ANTICIPATOR HEAT RELAY 1 NO FAN SWITCH 3 H2 ANTICIPATOR 1 W1 4 5 6 FALL SYSTEM COMPONENTS SUBBASE THERMOSTAT HEAT RELAY 2 W2 H2 2 8 NO SYSTEM SWITCH C1 RISE COMPRESSOR CONTACTOR 2 Y2 9 COMPRESSOR CONTACTOR 1 C1 ANTICIPATOR Y1 10 C2 L2 C2 ANTICIPATOR RC L1 (HOT) RISE 11 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 JUMPER RC, RH FOR SINGLE TRANSFORMER.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS Y FALL FAN SWITCH COMPRESSOR CONTACTOR AUTO 1 FAN RELAY G L1 (HOT) ON R 2 H2 CLOSED-DAY OPEN-NITE H1 ANTICIPATOR 3 1 B L 4 SYSTEM SWITCH 5 OVERRIDE HEAT 6 CO L2 B RELAY S JUMPER OFF RISE H1 2 COOL 8 P COOL CHANGEOVER VALVE W 9 RISE C1 C1 ANTICIPATOR T 10 1 POWERSUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 JUMPER HONEYWELL SUPPLIED, FIELD INSTALLED. M8004 Fig.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT H1 ANTICIPATOR SUBBASE SYSTEM COMPONENTS 1 W1 SYSTEM SWITCH HEAT HEAT RELAY 1 OFF 4 B 1 COOL FALL FAN SWITCH 8 G1 RISE C1 L1 (HOT) L2 R H1 LO 9 MED C1 ANTICIPATOR L1 G2 HIGH 10 L2 K1 RELAY K1 K1 K2 RELAY K2 O ON HI K2 K2 MED LO Y1 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. COMPRESSOR CONTACTOR 3 SPEED FAN SCHEMATIC M3729 Fig. 59. Schematic and hookup of T874A with Q674Q.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE COMPRESSOR CONTACTOR FALL Y1 H1 1 FAN RELAY H1 ANTICIPATOR FAN SWITCH G 4 AUTO 1 ON FALL H2 ANTICIPATOR L1 (HOT) L2 R 6 H2 ELEC. HT. RELAY W2 RISE 8 EVAPORATOR RELAY SYSTEM SWITCH C1 Y2 EVAP. 9 COOL CHANGEOVER RELAY OFF C1 ANTICIPATOR 1 O HEAT 10 M2862 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. Fig. 61. Schematic and hookup of T874C with Q674N.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT H2 SUBBASE SYSTEM COMPONENTS AUX. HT. RELAY NO FAN SWITCH FALL 1 W2 1 H2 ANTICIPATOR L1 (HOT) R NO SYSTEM SWITCH 4 FALL H1 YELLOW L2 C HEAT/COOL SWITCH GREEN 8 W1 WOOD/COAL RELAY 9 H1 ANTICIPATOR 10 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 1 M3725 Fig. 63. Schematic and hookup of T874F with Q674D. Used in wood/coal applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 1 W1 NO. 1 HEAT RELAY AUTO FAN SWITCH ON W2 H1 ANTICIPATOR B 4 HEAT DAMPER 6 FALL H1 L1 (HOT) L2 RH 8 L1 (HOT) L2 1 RC 9 RISE C1 COOL DAMPER SYSTEM SWITCH HEAT O OFF G 10 FAN RELAY C1 ANTICIPATOR COOL 11 Y2 NO. 1 COMP. RELAY Y1 FILTER LED (RED) X1 SERVICE LED (YELLOW) X2 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 1 M5976 Fig. 65.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS 1 X FAN RELAY FAN SWITCH 2 H1 C1 G AUTO H1/C1 ANTICIPATOR L1 (HOT) ON FALL 3 R L2 1 4 HEAT CHANGEOVER VALVE 5 SYSTEM SWITCH B FALL W2 H2 HEAT AUX. HT. RELAY 6 OFF COOL COMPRESSOR CONTACTOR Y 1 M5998 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. Fig. 67. Schematic and hookup of T874R with Q674B. Used in heat pump applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS FAN SWITCH LO AUTO HI Z RELAY Z CONT. G SYSTEM SWITCH FAN RELAY OFF COOL RISE R 8 C1 L1 (HOT) L2 1 9 COOL RELAY 10 Y C1 ANTICIPATOR 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M107A Fig. 69. Schematic and hookup of T874V with Q674R. Used in fan coil applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SYSTEM COMPONENTS SUBBASE THERMOSTAT 1 H1 ANTICIPATOR FAN SWITCH AUTO HEAT RELAY 1 3 ON FALL L1 (HOT) L2 RH CHECK 1 W1 H1 HEAT RELAY 2 4 W2 H2 6 FALL H2 ANTICIPATOR SYSTEM SWITCH X1 8 HEAT RISE G AUTO C1 9 FAN RELAY 2 COOL 10 Y2 C1 ANTICIPATOR COMPRESSOR CONTACTOR 2 Y1 C2 ANTICIPATOR 11 C2 RISE RC 1 2 COMPRESSOR CONTACTOR 1 L1 (HOT) POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS H ANTICIPATOR Y1 2 H1 FALL REVERSING VALVE RELAY 3 Y2 COMPRESSOR CONTACTOR FAN SWITCH 4 AUTO SETBACK G ON FALL FAN RELAY 6 8 CO L2 SYSTEM SWITCH 9 OPEN-NIGHT CLOSED-DAY OFF RISE 1 L1 (HOT) R 10 AUTO SETBACK RELAY C ANTICIPATOR C1 L RISE 1 M7008 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. Fig. 73. Schematic and hookup of T874G with Q674C.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE 1 H1 ANTICIPATOR W1 SYSTEM SWITCH OFF FILTER LED (YELLOW) HEAT RELAY 3 X AUTO 4 8 A SERVICE LED (RED) FAN SWITCH H1 FALL FAN RELAY AUTO 1 G ON L1 (HOT) L2 R 2 RISE 9 O C1 ANTICIPATOR C1 MOMENTARY CIRCUIT O 10 Y COMPRESSOR CONTACTOR 11 T EXTERNAL TEMP. READOUT THERMISTOR 12 T 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 MOMENTARY POSITION.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE 1 FALL FAN SWITCH SYSTEM COMPONENTS RESET LED (RED) X1 FAN RELAY AUTO CO G 3 ON FALL H2 L1 (HOT) L2 1 RH 4 2 FALL 6 HEAT CHANGEOVER VALVE H1 H1 ANTICIPATOR W1 HEAT RELAY 2 W3 8 HEAT RELAY 1 RISE SYSTEM SWITCH C1 9 W2 "B" RELAY OFF B C1 ANTICIPATOR 10 1 2 AUTO L1 (HOT) 1 L2 RC POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. "O" RELAY O JUMPER RH AND RC FOR SINGLE TRANSFORMER SYSTEM.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS RESET FAN SWITCH 1 H1 ANTICIPATOR X RESET LED (RED) G AUTO FALL H1 FAN RELAY ON 4 H2 2 FALL SETBACK CONTACT L2 1 R2 3 8 COOL CHANGEOVER VALVE 9 CO SYSTEM SWITCH C1 ANTICIPATOR RISE RISE O OFF 10 C1 L1 (HOT) R1 6 COMPRESSOR CONTACTOR AUTO Y 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 SETBACK CONTACT ON Q674C1124. 3 H2 ON T874G. M7027 Fig. 79.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS CHANGEOVER RELAY FALL H1 1 W1 B 4 FAN SWITCH FAN RELAY AUTO FALL G H2 ANTICIPATOR 6 ON H2 R 8 SYSTEM SWITCH RISE C1 OFF 9 COMPRESSOR CONTACTOR W2 Y1 AUTO C1 ANTICIPATOR 10 1 1 POWER SUPPLY. PROVIDE DISCONECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. L1 L2 (HOT) M5981 Fig. 81. Schematic and hookup of T874C with Q674C. Used in heat pump applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS L1 (HOT) 1 L2 H1 ANTICIPATOR HEAT RELAY 1 W1 1 FALL COMPRESSOR CONTACTOR 1 H1 Y1 FAN SWITCH AUTO 4 FAN RELAY G H2 ANTICIPATOR ON RC FALL HEAT RELAY 2 6 H2 W2 8 RISE RH C1 OFF 9 CHECK LED (RED) HEAT X1 COMPRESSOR CONTACTOR 2 AUTO C1 ANTICIPATOR 10 Y2 COOL C2 ANTICIPATOR 11 L2 RISE 1 C2 POWER SUPPLY. PROVIDE DISCONECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 1 L1 (HOT) M5982 Fig. 83.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS HEAT RELAY 1 H1 ANTICIPATOR H1 1 W1 COMPRESSOR CONTACTOR 1 FALL Y1 FAN SWITCH 4 FAN RELAY AUTO G 6 ON FALL L1 (HOT) R H2 ANTICIPATOR L2 H2 8 1 SYSTEM SWITCH RISE C1 OFF 9 HEAT HEAT RELAY 2 AUTO C1 ANTICIPATOR W2 COOL 10 COMPRESSOR CONTACTOR 2 C2 ANTICIPATOR RISE 11 1 C2 Y2 POWER SUPPLY. PROVIDE DISCONECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M5983 Fig. 85.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS W1 1 HEAT RELAY 1 FALL H1 Y1 FAN SWITCH H1 ANTICIPATOR COMPRESSOR CONTACTOR 1 AUTO G ON 4 FAN RELAY L1 (HOT) L2 RC H2 ANTICIPATOR 1 FALL W2 6 H2 HEAT RELAY 2 SYSTEM SWITCH B 2 RISE OFF 8 RH HEAT C1 L2 1 L1 (HOT) X AUTO SYSTEM FAULT CONTACT 9 COOL C1 ANTICIPATOR RISE C 10 C2 ANTICIPATOR 11 C2 COMPRESSOR CONTACTOR 2 LOCKOUT LED (RED) Y2 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS B H1 ANTICIPATOR HEAT RELAY 1 1 HEAT CHANGEOVER VALVE W1 FAN SWITCH FALL H1 AUTO COMPRESSOR CONTACTOR 1 ON 4 Y1 6 G FAN RELAY H2 FALL 8 C1 HEAT RELAY 2 SYSTEM SWITCH 9 AUTO 10 COOL L2 X SERVICE LED (RED) 11 Y2 C2 ANTICIPATOR COOL CHANGEOVER VALVE O 1 1 COMPRESSOR CONTACTOR 2 A C1 ANTICIPATOR RISE 1 L1 (HOT) RH FILTER LED (YEL) HEAT RISE L2 W2 OFF C2 L1 (HOT) RC H2 ANTICIPATOR
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES H1 ANTICIPATOR FALL SYSTEM COMPONENTS SUBBASE THERMOSTAT 1 L1 (HOT) L2 RH NO FAN SWITCH HEAT RELAY 1 W1 H1 1 HEAT RELAY 2 4 W2 H2 6 FALL H2 ANTICIPATOR SYSTEM SWITCH B 8 HEAT DAMPER OFF RISE O AUTO C1 9 COOL DAMPER 2 Y2 10 COMPRESSOR CONTACTOR 2 C1 ANTICIPATOR Y1 C2 ANTICIPATOR 11 C2 RISE RC 1 2 COMPRESSOR CONTACTOR 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT H1 SUBBASE SYSTEM COMPONENTS FALL HEAT FAN RELAY 1 W1 NO FAN SWITCH H1 ANTICIPATOR HEAT RELAY 4 6 H2 ANTICIPATOR FALL H2 W2 SYSTEM SWITCH 8 RISE C1 L2 1 OFF HEAT COMPRESSOR CONTACTOR 1 AUTO Y1 9 C1 ANTICIPATOR 10 L1 (HOT) RH COOL L1 (HOT) RC L2 C2 ANTICIPATOR 1 RISE 11 C2 1 Y2 COMPRESSOR CONTACTOR 2 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M4664 Fig. 93.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTATS SUBBASE 1 SYSTEM COMPONENTS L1 (HOT) R NO FAN SWITCH FALL H1 ANTICIPATOR L2 1 2 H1 3 OIL RELAY SYSTEM SWITCH 4 W2 OFF OIL LED (RED) FALL WOOD 5 X WOOD/OIL H2 WOOD LED (GREEN) OIL H2 ANTICIPATOR WOOD RELAY W1 6 1 POWER SUPPLY. PROVIDE DISCONECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M5984 Fig. 95. Schematic and hookup of T874F with Q674K. Used in wood/oil applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS 1 H2 COMPRESSOR CONTACTOR 2 H1 ANTICIPATOR FALL Y 3 G FAN SWITCH 3 4 CLOSED-DAY OPEN-NITE AUTO ON 5 RISE FAN RELAY C L2 L1 (HOT) R OVERRIDE LED (RED) 6 CO SERVICE LED (RED) 1 B H1 8 SYSTEM SWITCH L C1 B RELAY OVERRIDE RISE X AUTO 9 S OFF COMPRESSURE FAILURE JUMPER 2 P 10 W C1 ANTICIPATOR 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT H1 ANTICIPATOR SUBBASE 1 W1 3 OFF H1 HEAT RELAY 1 SYSTEM SWITCH 2 FALL SYSTEM COMPONENTS HEAT RELAY 2 4 W2 AUTO W3 5 6 Y2 H2 ANTICIPATOR 4 FALL H2 7 SERVICE LED (RED) FAN SWITCH A AUTO 8 C1 9 RISE G L2 ON C1 ANTICIPATOR 3 FAN RELAY R 2 1 10 L1 (HOT) MOMENTARY CIRCUIT O COMPRESSOR RELAY Y1 5 THERMISTER 1 11 T 12 T EXTERNAL TEMP. READOUT POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE H1 ANTICIPATOR 1 W1 3 OFF FALL HEAT RELAY 2 4 W2 AUTO HEAT RELAY 3 W3 5 FALL H3 Y2 6 4 H2 ANTICIPATOR FALL H2 HEAT RELAY 1 SYSTEM SWITCH 2 H1 SYSTEM COMPONENTS FAN SWITCH C2 ANTICIPATOR COMPRESSOR CONTACTOR 2 SERVICE LED (RED) A AUTO 7 G 3 L2 ON 8 FAN RELAY R C1 2 1 9 MOMENTARY CIRCUIT RISE O C2 L1 (HOT) COMPRESSOR RELAY 10 RISE Y1 C2 ANTICIPATOR 5 THERMISTER 11 T 12 T EXTERNAL TEMP.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS COMPRESSOR CONTACTOR 1 H1/C1 ANTICIPATOR 2 H1 F AUTO FAN RELAY ON C1 HIGH PRESSURE INTERNAL THERMOSTAT SWITCH M FAN SWITCH FALL OVERLOAD SWITCH V 3 4 FALL SUPPL. ELEC. HT. RELAY EM. HT. RELAY CONTACT TIME DELAY FAN RELAY Y 5 H2 OUTDOOR THERMOSTAT 6 2 H2 ANTICIPATOR EM. HT. RELAY 7 E SYSTEM SWITCH EM. HT. LED (RED) EM. HT. 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS COOL CHANGEOVER VALVE 1 L1 (HOT) O 1 H1 ANTICIPATOR L2 FAN SWITCH AUTO G ON 2 FAN RELAY R OUTDOOR THERMOSTAT FALL H1 4 W2 HEAT RELAY 1 FALL H2 6 HEAT RELAY HEAT RELAY 2 CONTACT 1 H2 ANTICIPATOR SYSTEM SWITCH E 8 HEAT RELAY CONTACT 2 2 HEAT RELAY 3 SUPL. HT. 9 L HEAT RISE CO SUPL. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 1 FAN SWITCH H1 ANTICIPATOR FAN RELAY AUTO G ON 2 HEAT RELAY 2 W2 H1 FALL K L 4 SYSTEM SWITCH 6 FALL EM. HT. LED (RED) EM. HT. H2 ANTICIPATOR EM. HT. RELAY SYSTEM MONITOR SWITCH IHRI C HEAT H2 R 8 OFF RHI COMPRESSOR CONTRACTOR COOL C1 ANTICIPATOR Y RISE 10 W1 C1 1 HEAT RELAY 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 1 M8384 L1 L2 (HOT) Fig. 105.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS COOL CHANGEOVER VALVE 2 O FAN SWITCH FAN RELAY AUTO H1 ANTICIPATOR H1 G FALL 3 ON OUTDOOR THERMSTAT SUPPL. HT. RELAY 4 H2 ANTICIPATOR Y1 5 EM. HT. RELAY CONTACT H2 COMPRESSOR CONTACTOR 2 FALL E 8 SYSTEM SWITCH EM. HT. RELAY COMP. FAILURE L C1 ANTICIPATOR C1 RISE 10 C2 ANTICIPATOR EM. HT. LED (RED) EM. HT. C HEAT L1 (HOT) OFF R 11 COOL C2 L2 RISE 1 Y 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS AUX. HT. RELAY 1 W AUX. HT. LED (GREEN) 2 B H1 C1 FALL H1/ C1 ANTICIPATOR 3 FAN SWITCH AUTO EM. HT. LED (RED) F G 4 ON COMPRESSOR FAILURE FAN RELAY L1 (HOT) L2 1 R 5 RESET HEATER FALL X2 H2 6 T OUTDOOR THERMOSTAT SYSTEM SWITCH COOL CHANGEOVER VALVE EM. HT. HEAT 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS RESET 1 L1 (HOT) L2 1 V 2 2 H1 ANTICIPATOR VR INTERNAL THERMOSTAT COMPRESSOR CONTACTOR M 3 FAN SWITCH FAN RELAY H1 OVERLOAD SWITCH HI PRESSURE SWITCH AUTO FALL 4 F ON SERVICE SERVICE LED (RED) L OUTDOOR THERMOSTAT SUPL. ELEC. HT. RELAY 5 S H2 6 Y H2 ANTICIPATOR 7 ELEC. HT. RELAY SYSTEM SWITCH E EM. HT. LED (YELLOW) EM. HT. 8 X HEAT C1 C1 ANTICIPATOR TIME DELAY FAN RELAY EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS V 1 RESET HEATER 1 L1 (HOT) 2 L2 VR 2 H1/ C1 ANTICIPATOR COMPRESSOR CONTACTOR 3 M FAN SWITCH 4 INTERNAL THERMOSTAT OVERLOAD SWITCH AUTO HIGH PRESSURE SWITCH F ON H1 FAN RELAY C1 SERVICE L SERVICE LED (RED) FALL OUTDOOR THERMOSTAT 5 6 Y EM. HT. RELAY SYSTEM SWITCH H2 7 SUPPL. ELEC. HT. RELAY E EM. HT. X OFF A COOL C815A OUTDOOR THERMISTOR COOL CHANGEOVER VALVE H2 ANTICIPATOR 1 EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE COOL CHANGEOVER VALVE FALL O 2 H1 FAN SWITCH C1 H1/C1 ANTICIPATOR AUTO FAN RELAY G L1 (HOT) ON R 3 4 H2 ANTICIPATOR 5 SYSTEM SWITCH 1 L1 EM. HT. 6 HEAT OFF H2 FALL COOL EM. HT. LED (RED) X AUX. HT. LED (GREEN) AUX. HT. RELAY W2 1 L2 COMPRESSOR FAILURE POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. COMPRESSOR CONTACTOR Y EM. HT. RELAY E M8383 Fig. 112.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) L2 1 R HEAT CONTRACTOR 3 EM. HT. RELAY H1/C1 ANTICIPATOR EM. HT. RELAY 1 W3 HEAT CONTRACTOR 2 OUTDOOR THERMOSTAT 2 DEFROST RELAY 3 H1 W2 HEAT CONTRACTOR 1 HIGH LIMIT SWITCH B DEFROST RELAY REVERSING VALVE C1 FALL FAN SWITCH AUTO 4 ON H2 FALL CHECK LED (GREEN) L 5 OPTIONAL COMP. FAILURE DEVICE X2 H2 ANTICIPATOR 6 SYSTEM SWITCH X1 EM. HT. LED (RED) EM. HT. RELAY E EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS 1 RESET HEATER M2 OUTDOOR THERMOSTAT H1 ANTICIPATOR 2 HIGH SPEED COMPRESSOR CONTACTOR M 3 FAN SWITCH FAN RELAY AUTO LOW SPEED COMPRESSOR CONTACTOR F H1 ON FALL L1 (HOT) L2 1 V 4 5 R 2 H2 L FALL COOL CHANGEOVER VALVE SERVICE 6 H2 ANTICIPATOR X EM. HT. LED (YELLOW) 7 EM. HT. RELAY E OUTDOOR THERMOSTAT 8 SYSTEM SWITCH RISE C1 C1 ANTICIPATOR EM. HT. SUPPL. ELEC. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS (HOT) L1 L2 1 H1/C1 ANTICIPATOR R 2 FALL ODT 1 H1 RTD 1 C1 EHR 1 RTD 2 W3 3 4 FAN SWITCH ODT 2 AUTO EHR 2 ON H2 ANTICIPATOR W2 5 H2 RTD 3 RTD 1 AUX. HT. LED (GREEN) 6 2 FALL X EM. HT. LED (RED) SYSTEM SWITCH SYSTEM MONITOR RD L FAN RELAY G EM. HT. O HEAT OFF COOL CHANGEOVER VALVE E COOL EM. HT. RELAY CHP LACO Y B 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 2 H1/C1 ANTICIPATOR H1 C1 3 FALL E FAN SWITCH EM. HT. RELAY AUTO X EM. HT. LED (RED) ON B 4 R AUX. HT. RELAY 5 W2 H2 ANTICIPATOR 6 2 SYSTEM SWITCH COMPRESSOR CONTACTOR H L1 (HOT) L2 EM. HT. H2 FALL A HEAT COMP. FAULT LED (YELLOW) OFF COOL 1 2 1 Y Y G G R COM POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SYSTEM COMPONENTS SUBBASE THERMOSTAT L1 (HOT) L2 1 R DEFROST RELAY ENTHALPY CONTROL RELAY 2 B FALL H1 HEAT RELAY CONTACT 1 H1 ANTICIPATOR MOTOR 3 G 3 FAN SWITCH ECONOMIZER RELAY DEFROST SWITCH OUTDOOR FAN RELAY 1 AUTO 4 ON H2 ANTICIPATOR ENTHALPY CONTROL 5 FALL DEFROST SWITCH RELAY TM1 2 TM2 LOW AMBIENT THERMOSTAT 1 ENTHALPY CONTROL RELAY 2 H2 OUTDOOR FAN RELAY 3 OUTDOOR FAN RELAY 2 6 1ST STAGE LOW PRESSURE LIMIT 8 Y1 C1 ENTHALPY
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SYSTEM COMPONENTS SUBBASE THERMOSTAT 1 L1 (HOT) L2 1 R H1 DEFROST RELAY ECONOMIZER RELAY FALL 2 B H2 HEAT RELAY CONTACT 1 FALL G H1 ANTICIPATOR H2 ANTICIPATOR 3 4 H3 ANTICIPATOR ECONOMIZER RELAY DEFROST SWITCH FAN SWITCH MOTOR 3 AUTO OUTDOOR FAN RELAY 1 ON DEFROST RELAY ENTHALPY CONTROL DEFROST SWITCH RELAY 2 5 TM1 TM2 OUTDOOR THERMOSTAT 1 FALL H3 ECONOMIZER RELAY 2 6 1ST STAGE LOW PRESSURE LIMIT 8 C1 Y1 RISE ECONOMISER RELAY 1
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 1 L1 (HOT) L2 C815A OUTDOOR THERMISTOR RESET HEATER 1 T H2 ANTICIPATOR W2 2 FAN SWITCH AUX. HT. RELAY AUTO G ON 3 FAN RELAY R X 4 H1 C1 FALL SERVICE LED (YELLOW) SYSTEM SWITCH 5 SERVICE Z EM. HT. C1 ANTICIPATOR EM. HT. LED (RED) HEAT 6 OFF K COOL FALL 1 H2 11 Y 12 W1 EM. HT. RELAY COMPRESSOR CONTACTOR H1 ANTICIPATOR HEAT CHANGEOVER RELAY POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT 2 H1 ANTICIPATOR SYSTEM COMPONENTS L1 (HOT) L2 1 R FAN SWITCH COMPRESSOR FAILURE 3 ODT1 AUTO RTD2 EHR1 H1 ON FALL 4 ODT2 EM. HT. LED (RED) 5 H2 ANTICIPATOR L RTD1 EHR2 RTD3 X 6 AUX. HT. LED (GRN) H2 FALL RTD1 W2 RD SYSTEM SWITCH 8 C1 ANTICIPATOR COOL CHANGEOVER VALVE EM. HT. HEAT 10 FAN RELAY G EM. HT. RELAY O OFF E COOL LACO C1 COMPRESSOR CONTACTOR CHP Y RISE HEAT CHANGEOVER VALVE B 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT FAN SWITCH SYSTEM COMPONENTS FAN RELAY G AUTO 2 FALL L2 ON R H1 C1 H1/C1 ANTICIPATOR 3 1 L1 (HOT) W2 AUX. HT. RELAY K EM. HT. RELAY 4 L CO SYSTEM SWITCH 5 FALL EM. HT. HEAT H2 H2 ANTICIPATOR 6 EM. HT. LED (YELLOW) OFF C SERVICE LED (RED) COMPRESSOR CONTACTOR COOL Y 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. W1 CHANGEOVER VALVE Z SERVICE Fig. 122.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 L2 (HOT) ODT 1 1 2 H1 C1 EHR 1 H1/C1 ANTICIAPTOR RTD 2 RTD 1 FALL 3 4 ODT 2 FAN SWITCH EHR 2 AUTO RTD 3 ON R 5 L H2 FALL EM. HT. LED (RED) H2 ANTICIPATOR COMPRESSOR MONITOR X 6 AUX. HT. LED (GREEN) RTD 1 W2 8 SYSTEM SWITCH RD EM. HT. 10 FAN RELAY G 2 COOL CHANGEOVER VALVE HEAT OFF 1 2 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. O EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE L1 L2 (HOT) 1 FALL R FAN SWITCH H1 2 AUTO 3 ON H1 ANTICIPATOR COMPRESSOR CONTACTOR Y G EM. HT. OR SUPL. HT. LED (RED) 5 OUTDOOR THERMOSTAT L H2 6 RISE 8 SYSTEM SWITCH 9 EM. HT. OR SUPL. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE L1 (HOT) R L2 L 2 H1/C1 ANTICIPATOR 3 EM. HT. LED (RED) 3 FAN SWITCH C1 FALL 4 2 ON X H2 ANTICIPATOR H2 FALL AUX. HT. RELAY W3 AUTO H1 1 AUX. HT. LED (GRN) 6 AUX. HT. RELAY W2 SYSTEM SWITCH EM. HT. FAN RELAY G HEAT COOL CHANGEOVER VALVE OFF O COOL E EM. HT. RELAY Y COMPRESSOR CONTACTOR B 1 "B" RELAY POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS COOL CHANGEOVER VALVE 1 L1 (HOT) L2 1 O H1 ANTICIPATOR FAN SWITCH FAN RELAY AUTO G 2 ON R FALL H1 OUTDOOR THERMOSTAT 4 W2 FALL HEAT RELAY 1 6 H2 H2 ANTICIPATOR HEAT RELAY CONTACT 1 8 CO HEAT RELAY CONTACT 2 2 9 RISE HEAT RELAY 3 SUPL. HT. L 10 HEAT SUPL. HT. LED (RED) COOL RISE C1 E SYSTEM SWITCH C1 ANTICIPATOR HEAT RELAY 2 C Y 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS R H1/C1 ANTICIPATOR 2 FALL C1 L2 A 1 SERVICE LED (RED) FAN SWITCH H1 L1 (HOT) ODT1 RD EHR1 RTD1 W3 3 AUTO ON RTD1 4 ODT2 RTD2 EHR2 RTD3 W2 FALL H2 ANTICIPATOR 5 AUX. HT. LED (GREEN) SYSTEM SWITCH H2 X EM. HT. 6 EM. HT. LED SYSTEM (YELLOW) MONITOR HEAT OFF RD L COOL FAN RELAY G 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. O COOL CHANGEOVER VALVE EM.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 2 O COOL CHANGEOVER VALVE FAN SWITCH H1 G C1 AUTO FAN RELAY FALL ON L1 (HOT) L2 1 R H1/C1 ANTICIPATOR 3 W1 4 5 AUX. HT. LED (YELLOW) SYSTEM SWITCH FALL 6 EM. HT. RELAY E COMPRESSOR FAILURE EM. HT. H2 2 CHECK LED (RED) HEAT X H2 ANTICIPATOR OFF C COOL 11 C815A OUTDOOR THERMISTOR SYSTEM LED (GREEN) RESET T 12 1 2 COMPRESSOR CONTACTOR POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) L2 1 H1/C1 ANTICIPATOR 2 AUTO FAN SWITCH ON R 3 H1 W2 C1 HCR 1 RESET HEATER FALL L 4 SYSTEM SWITCH ODT SUPL. HT. LED (RED) SUPL. HT. FAN RELAY G 6 HEAT COOL CHANGEOVER VALVE 2 H2 ANTICIPATOR H2 C FALL O COOL E HCR 2 HCR 3 Y 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 FOR Q674L1454, COMPRESSOR CONTACTOR IS "OFF". HCR 1 HCR 2 M4723 Fig. 131.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS O 2 FAN SWITCH FALL H1 C1 COOL CHANGEOVER VALVE FAN RELAY AUTO H1/C1 ANTICIPATOR G ON L1 (HOT) R 1 3 L2 3R 4 W1 5 SYSTEM SWITCH AUX. HT. LED (YELLOW) EM. HT. 6 H2 H2 ANTICIPATOR FALL SEQ 1 2 SEQ 2 HEAT E OFF COOL EM. HT. LED (RED) EM. HT. RELAY 4R 4R X C SYSTEM LED (GREEN) 11 5R C815A OUTDOOR THERMISTOR 4R HPS T 12 RESET Y 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS RTD 1 ODT 1 1 H1 EHR 1 RTD 2 C1 FALL ODT 2 2 EHR 2 H1/C1 ANTICIPATOR RDT 3 FAN SWITCH 3 FAN RELAY AUTO G ON 4 L1 (HOT) 1 L2 R H2 ANTICIPATOR W2 5 AUX. HT. LED (GREEN) RTD 1 EM. HT. RELAY E 6 FALL COMP. FAILURE H2 L SYSTEM SWITCH 8 RD EM. HT. LED (RED) CHANGEOVER VALVE (HEAT) EM. HT. B HEAT X OFF COOL LACO 10 COMPRESSOR CONTACTOR CHP Y CHANGEOVER VALVE (COOL) O 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS FAN SWITCH L1 (HOT) R AUTO H1/C1 ANTICIPATOR 2 L2 1 ON W2 HCR 1 3 H1 C1 L SUPL. HT. LED (RED) RESET HEATER FALL HCR 2 HCR 1 ODT C 4 SYSTEM SWITCH G FAN RELAY SUPL. HT. O 6 COOL CHANGEOVER VALVE HEAT H2 ANTICIPATOR OFF E COOL H2 HCR 3 HCR 2 FALL Y COMPRESSOR CONTACTOR 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M2017 Fig. 135.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS RTD 1 ODT 1 1 H1 EHR 1 RTD 2 C1 FALL ODT 2 2 EHR 2 H1/C1 ANTICIPATOR 3 RDT 3 W3 FAN SWITCH FAN RELAY AUTO G ON L1 (HOT) 1 L2 R 4 H2 ANTICIPATOR W2 5 AUX. HT. LED (GREEN) RTD 1 EM. HT. RELAY E 6 FALL H2 COMP. FAILURE EM. HT. LED (RED) SYSTEM SWITCH RD L CHECK LED (RED) EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 1 J R1 NO2 S1 RELAY 2 S1 NC H1 S FALL FAN SWITCH H1 ANTICIPATOR SOLIENOID RELAY AUTO ON FAN RELAY G L1 (HOT) L2 1 R 3 2 4 C 5 H2 H2 ANTICIPATOR FALL AUX. HT. RELAY H2 SYSTEM SWITCH HEAT RISE 8 C1 COMPRESSOR CONTACTOR R1 NC1 7 H1 OFF R2 NO1 COOL 9 REVERSING VALVE C1 ANTICIPATOR 10 O 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) L2 1 1 FALL H1 ANTICIPATOR T H1 2 C815A OD THERMISTOR W3 H2 H2 ANTICIPATOR FALL AUX. HT. RELAY 3 AUX. HT. LED (GREEN) FAN SWITCH AUTO H3 ANTICIPATOR 4 U G ON FAN RELAY H3 FALL EM. HT. LED (RED) 5 R E 6 RESET EM. HT. RELAY COMPRESSOR MONITOR L CHECK LED (RED) RISE X 8 C1 SYSTEM SWITCH B EM.HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SYSTEM COMPONENTS SUBBASE THERMOSTAT R FALL FAN SWITCH 1 H1 ANTICIPATOR H1 W1 FAN RELAY AUTO G ON 4 FALL HEAT RELAY 2 6 W2 H2 H2 ANTICIPATOR EM. HT. LED (RED) SYSTEM SWITCH OFF X2 EM. HT. RELAY RISE EM. HT. C1 E 8 HEAT COMPRESSOR CONTACTOR 2 9 AUTO C1 ANTICIPATOR Y2 COOL COMPRESSOR CONTACTOR 1 10 C2 ANTICIPATOR C2 RISE L1 (HOT) L2 1 HEAT RELAY 1 Y1 11 M8376 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE 1 FALL Y1 H1 ANTICIPATOR H1 COMPRESSOR CONTACTOR FAN SWITCH 2 FAN RELAY AUTO G 4 ON FALL R L1 (HOT) 6 L2 SYSTEM SWITCH H2 H2 ANTICIPATOR 1 OFF W1 AUTO 8 RISE AUX. HT. RELAY C CO C1 ANTICIPATOR AUX. HT. LED (RED) 9 O 1 10 C1 COOL CHANGEOVER VALVE POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M8378 RISE Fig. 143. Schematic and hookup of T874G with Q674B.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS (HOT) L1 L2 1 V FAN SWITCH H1 ANTICIPATOR DEFROST RELAY SUP. ELEC. HT. RELAY 1 Y AUTO 2 FALL H1 OUTDOOR THERMOSTAT ON EM. HT. RELAY 4 FAN RELAY SYSTEM SWITCH H2 ANTICIPATOR FALL TIME DELAY FAN RELAY F EM. HT. RELAY 6 OFF H2 E EM. HT. LED (RED) EM. HT. 8 HEAT FALL COOL CHANGEOVER VALVE AUTO 9 R CO COOL C1 ANTICIPATOR COMPRESSOR CONTACTOR 10 1 RISE C1 INTERNAL THERMOSTAT M POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS A 2 H1 H1 ANTICIPATOR MODE SIGNAL 1 3 FALL 3 FAN SWITCH 2 4 AUTO G FAN RELAY ON 5 L1 (HOT) L2 1 R H2 ANTICIPATOR 2 S SERVICE LED (RED) 6 W3 FALL H2 HEAT RELAY 2 HEAT RELAY 1 SYSTEM SWITCH W2 AUX. HT. LED (GRN) OFF X 8 COOL CO EM. HT. LED (YEL) AUTO COOL CHANGEOVER VALVE O 9 RISE L COMPRESSOR CONTACTOR HEAT EM. HT. Y EM. HT. RELAY C1 ANTICIPATOR RISE E 10 C1 T 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 2R EMR4 FALL W1 1 H1 1R Y1 H1 ANTICIPATOR 4R2 2R2 5R 4 FALL G EMR4 H2 H2 ANTICIPATOR 6 3R W2 EMR2 THERMAL SWITCHES FOR HEATING ELEMENTS HTR 1 8 RISE FAN SWITCH C1 HTR 3 AUTO HTR 2 EMR3 ON 9 C1 ANTICIPATOR RISE 3 C2 10 2 EM. HT. LED C2 ANTICIPATOR X1 11 SYSTEM SWITCH 3R1 Z OFF 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS COOL CHANGEOVER VALVE H1 ANTICIPATOR 1 R COMPRESSOR CONTACTOR FALL INTERNAL THERMOSTAT M 2 H1 OVERLOAD SWITCH FAN SWITCH AUTO 3 F HI PRESSURE SWITCH FAN RELAY ON OUTDOOR THERMOSTAT FALL 5 SUPL. ELEC. HT. RELAY Y H2 EM. HT. RELAY CONTACT H2 ANTICIPATOR TIME DELAY FAN RELAY 6 SYSTEM SWITCH RISE 8 TIME DELAY FAN RELAY E OFF EM. HEAT LED (RED) EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS EM. HT. RELAY CONTACT 1 L2 L1 (HOT) H1 ANTICIPATOR 1 R 1 W2 2 FAN SWITCH AUTO FALL H1 T6031 REFRIGERATON/ TEMPERATURE CONTROLLER EM. HT. LED (RED) ON EM. HT. E 4 2 6 SYSTEM SWITCH H2 ANTICIPATOR EM. HT. RELAY X H OFF FALL H2 Y EM. HT. HEAT R8233B Y COMPRESSOR CONTACTOR R COM AUTO G 8 G EM. HT. COOL CO W RISE 9 O SEQUENTIAL RELAY O FAN C1 ANTICIPATOR C DF RS 10 C1 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 1 L1 L2 (HOT) HEAT RELAY W1 COMPRESSOR CONTRACTOR 1 1 FALL H1 Y1 FAN SWITCH H1 ANTICIPATOR FAN RELAY AUTO G ON 4 RC 3 FALL H2 ANTICIPATOR H2 HEAT RELAY 2 W2 6 SYSTEM SWITCH RISE RH EM. HT. RELAY OFF 8 E EM. HT. C1 HEAT 9 B AUTO 10 RISE C1 ANTICIPATOR 2 X2 COOL EM. HEAT LED (RED) 11 C2 X1 C2 ANTICIPATOR COMPRESSOR CONTRACTOR 2 O Y2 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 1 R 1 H1 ANTICIPATOR 2 FAN SWITCH AUTO L2 L1 (HOT) W2 T6031 REFRIGERATION TEMPERATURE CONTROLLER E FALL ON H1 EM. HT. LED (RED) 4 EM. HT. RELAY CONTACT 1 EM. HT. X 2 H2 ANTICIPATOR 6 SYSTEM SWITCH OFF EM. HT. RELAY A COMPRESSOR CONTACTOR COMP. FAULT LED (YELLOW) H2 EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE H1 ANTICIPATOR R 2 RTD1 L1 (HOT) OTD1 FAN SWITCH L2 1 3 EHR1 AUTO RTD2 2 FALL H1 W3 ON 4 ODT2 W2 H2 ANTICIPATOR EHR2 RTD3 5 H2 FALL 6 AUX. HT. LED (GRN) SYSTEM SWITCH RTD1 X OFF SYSTEM MONITOR 8 COOL 9 RISE C1 ANTICIPATOR CHANGEOVER EM. HT. LED (RED) AUTO FAN RELAY L G HEAT RD COOL CHANGEOVER VALVE EM. HT. 10 O RISE EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 L2 (HOT) 1 COOL CHANGEOVER VALVE H1 ANTICIPATOR FALL O 1 FAN SWITCH ON H1 FAN RELAY 2 G ON R 4 FALL AUX. HT. RELAY CONTACT OUTDOOR THERMOSTAT EM. HT. RELAY E H2 H2 ANTICIPATOR 6 RISE 8 SYSTEM SWITCH OFF L1 CO 9 HEAT X AUTO C1 ANTICIPATOR EM. HT. LED (GREEN) COOL 10 RISE COMPRESSOR FAILURE EM. HT. LED (RED) EM. HT. AUX. HT. RELAY W2 COMPRESSOR CONTACTOR C1 1 Y POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) L2 1 1 O H1 ANTICIPATOR COOL CHANGEOVER VALVE 2 H1 E FAN SWITCH EM. HT. RELAY AUTO G FALL ON 2 4 FAN RELAY B R HEAT CHANGEOVER VALVE H2 W2 6 H2 ANTICIPATOR FALL SYSTEM SWITCH OFF AUX. HT. RELAY L1 8 EM. HT. AUTO C1 ANTICIPATOR 9 C1 1 RISE COMPRESSOR FAILURE EM. HT. LED (RED) HEAT CO RISE X COOL AUX. HT. LED (GREEN) Y 10 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS COOL CHANGEOVER VALVE O 1 H1 ANTICIPATOR L1 L2 (HOT) 1 FAN RELAY G FAN SWITCH HEAT RELAY CONTACT AUTO 2 OFF R H1 FALL AUX. HT. RELAY 4 6 FALL H2 W OUTDOOR THERMOSTAT SYSTEM SWITCH E HEAT RELAY CONTACT H2 ANTICIPATOR EM. HT. RELAY 8 EM.HT. RISE 9 CO EM. HT. LED (RED) AUTO X OFF COMPRESSOR CONTACTOR LIMIT C1 ANTICIPATOR Y 10 RISE 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS COOL CHANGEOVER VALVE 1 L1 (HOT) L2 O 1 H1 ANTICIPATOR FAN SWITCH AUTO G ON 2 FAN RELAY R H1 OUTDOOR THERMOSTAT FALL W2 4 EM. HT. RELAY 1 H2 6 EM. HT. RELAY EM. HT. RELAY 2 CONTACT 1 H2 ANTICIPATOR FALL SYSTEM SWITCH E 2 8 EM. HT. RELAY CONTACT 2 EM.HT. RELAY 3 CO L C1 ANTICIPATOR SUPL. HT. RISE 9 SUPL. HT. LED (RED) ON C COMPRESSOR CONTACTOR 1 OFF C1 RISE Y 10 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THEROMSTAT SUBBASE SYSTEM COMPONENTS C815A OUTDOOR THERMISTOR T 1 FAN RELAY FALL FAN SWITCH G H1 2 AUTO COOL CHANGEOVER VALVE ON H1 ANTICIPATOR O 3 R 1 4 FALL L1 (HOT) L2 H2 OUTDOOR THERMOSTAT 5 X2 AUX. HT. LED (GREEN) RESET HEATER 6 SYSTEM SWITCH RISE 8 EM. HT. B AUTO CO EM. HT. LED (RED) OFF C1 Y 10 C1 ANTICIPATOR 1 EM. HT. RELAY F 9 RISE AUX. HT. RELAY W COMPRESSOR CONTACTOR POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L2 L1 (HOT) HEAT DAMPER 1 B H1 ANTICIPATOR HEAT RELAY 1 W1 1 FAN SWITCH FAN RELAY H1 AUTO FALL 4 G ON H2 ANTICIPATOR HEAT RELAY 2 6 1 AUTO 8 H2 FALL SYSTEM SWITCH 9 W2 R OFF RESET S1 1 CO RESET CIRCUIT COOL CHANAGEOVER VALVE O FALL 10 S2 C1 ANTICIPATOR RESET CIRCUIT C1 Y RISE SERVICE LED (RED) 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) L2 1 H1 ANTICIPATOR 2 O COOL CHANGEOVER VALVE FALL 3 Y FAN SWITCH H1 COMPRESSOR CONTACTOR AUTO G 4 ON R 6 FAN RELAY RISE 2 SYSTEM SWITCH 8 CO L MALFUNCTION LED (RED) OFF 9 C1 ANTICIPATOR RISE AUTO X 10 C1 HEAT CHANGEOVER VALVE B 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 R-L JUMPER SUPPLIED BY HONEYWELL. MALFUNCTION SWITCH M5726 Fig. 164.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) 1 L2 FALL FAN SWITCH H1 1 H1 ANTICIPATOR AUTO W1 ON HEAT RELAY 1 AUX. HT. LED (GREEN) 4 EM. HT. LED (RED) X W2 FALL 6 HEAT RELAY 2 H2 RH SYSTEM SWITCH H2 ANTICIPATOR L 8 OFF SYSTEM MONITOR EM. HT. RISE HEAT C1 9 EM. HT. RELAY E AUTO G FAN RELAY COOL 10 RC COMRESSOR CONTACTOR 1 C1 ANTICIPATOR Y1 C2 ANTICIPATOR COMRESSOR CONTACTOR 2 11 Y2 RISE C2 L2 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L2 (HOT) L1 1 R ODT 1 H1 ANTICIPATOR 2 FALL RTD 1 H1 3 4 RTD 2 FAN SWITCH ODT 2 AUTO EHR 2 ON H2 ANTICIPATOR 5 H2 EHR 1 RTD 3 W2 RTD 1 AUX. HT. LED (GREEN) FALL X SYSTEM SWITCH EM. HT. LED (RED) COMPRESSOR FAILURE RD OFF L 7 FALL CHANGEOVER 8 EM. HT. HEAT G AUTO B FAN RELAY HEAT CHANGEOVER VALVE COOL 9 EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS W3 W3 RELAY O COOL CHANGEOVER VALVE L H1 ANTICIPATOR 1 FAN SWITCH COMPRESSOR MONITOR FAN RELAY G AUTO ON C ANTICIPATOR L1 (HOT) L2 R 2 1 W2 H1 C 4 5 H2 ANTICIPATOR H2 EM. HT. LED (RED) 3 FALL SYSTEM SWITCH E EM. HT. RELAY EM. HT. HEAT 6 AUX. HT. LED (GRN) AUX. HT. RELAY OFF FALL COOL X 3 X2 HEAT CHANGEOVER VALVE B 11 W1 RELAY 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE 1 FALL H1 ANTICIPATOR SYSTEM COMPONENTS O FAN SWITCH COOL CHANGEOVER VALVE AUTO 2 G ON FAN RELAY H1 B 3 B RELAY W3 4 AUX HT. RELAY SYSTEM SWITCH H2 ANTICIPATOR L2 E OFF HEAT EM. HT. RELAY EM. HT. LED (RED) AUTO X 2 COOL 8 C1 1 L EM. HT. H2 FALL RISE AUX. HT. LED (GREEN) AUX. HT. RELAY 9 W2 C1 ANTICIPATOR Y 10 CO 11 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS W3 W1 RELAY W3 RELAY W1 2 H1 FALL H1 ANTICIPATOR B RELAY FAN SWITCH B 3 FAN RELAY AUTO G 4 L1 (HOT) ON R 5 AUX. HT. RELAY 6 H2 ANTICIPATOR SYSTEM SWITCH AUX. HT. LED (GREEN) OFF EM. HT. H2 X 3 HEAT 8 FALL 9 CO C1 ANTICIPATOR L2 1 W2 EM. HT. LED (RED) AUTO COOL L E RISE 10 RISE O C1 2 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE L1 (HOT) L2 R 2 1 FALL H1 Y FAN SWITCH 3 H1 ANTICIPATOR O.D.T. COMPRESSOR CONTACTOR AUTO G 4 ON FAN RELAY H2 ANTICIPATOR EM. HT. LED (RED) FALL H2 HCR1 W1 5 HCR1 6 F 8 C 9 E HCR2 2 CO SYSTEM SWITCH RISE C1 ANTICIPATOR HCR2 X EM. HT. 10 "X" RELAY AUTO "P" RELAY OFF P 11 C1 RISE CO HCR3 O 12 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS FAN SWITCH 2 FAN RELAY H1 ANTICIPATOR AUTO G 3 ON R 4 O FALL FAULT LED (RED) H1 C 8 RISE COOL CHANGEOVER VALVE 2 C1 ANTICIPATOR SYSTEM SWITCH CO CHECK FILTER 3 LED (YELLOW) 9 OFF 10 L1 (HOT) L2 1 AUTO 11 12 Y C1 1 RISE COMPRESSOR CONTACTOR POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M1400 Fig. 173. Schematic and hookup of T874H with Q674C.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS H1 ANTICIPATOR 1 O FAN SWITCH 2 FAN RELAY ON COOL CHANGEOVER VALVE G AUTO FALL L1 (HOT) R L2 1 4 H2 ANTICIPATOR H.C.R. 1 O.D.T. W2 6 H.C.R. 1 H.C.R.2 H.C.R. 2 H.C.R.3 FALL 8 SYSTEM SWITCH E C1 ANTICIPATOR SUPL. HT. 9 L ON CO RISE MANUAL (RED) AUTO (YEL) OFF C 10 Y HEAT PUMP (GRN) C1 RISE DEFROST (RED) COMPRESSOR CONTACTOR D 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS LOCKOUT (RESET) RELAY H1 ANTICIPATOR FAN SWITCH 1 X RESET LED (RED) AUTO G H1 ON FALL FAN RELAY 4 3 L1 (HOT) L2 R1 6 SYSTEM SWITCH H2 1 R2 OFF FALL AUTO 7 2 B CO 8 RISE 2 HEAT CHANGEOVER VALVE O COOL CHANGEOVER VALVE 9 Y C1 ANTICIPATOR 10 C1 RISE 1 COMPRESSOR CONTACTOR POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS W1 1 DEFROST RELAY H1 ANTICIPATOR OUTDOOR THERMOSTAT REVERSING VALVE HEAT RELAY 2 EM.HT. RELAY CONTACT 2 EM.HT. RELAY CONTACT HEAT RELAY 3 H1 W3 FALL 4 FAN SWITCH FAN RELAY H2 ANTICIPATOR AUTO G ON 5 1 L1 (HOT) L2 R H2 FALL 6 W2 SYSTEM SWITCH OFF EM. HT. LED (RED) EM. HT. RELAY X EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS L1 (HOT) FAN DELAY RELAY 1 CHANGEOVER VALVE ELEC. HT. RELAY STG. 1 L2 R-11 R-11 FALL 1 W1 H1 R-10 H1 ANTICIPATOR R-8 R-6 OVERLOAD Y1 FAN SWITCH FAN RELAY AUTO G ON R-6 R-1 R-2 4 FALL R H1 H2 ANTICIPATOR COMPRESSOR CONTACTOR R-10 6 W2 8 EM. HT. LED (RED) ELEC. HT. RELAY STG. 2 E C1 X2 SYSTEM SWITCH RISE RISE 10 R-5 2 9 C1 ANTICIPATOR EM. HT. AUTO EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENT L1 2 TIME CLOCK CO 3 H2 L2 (HOT) FALL 1 Y FALL COMPRESSOR RELAY FAN SWITCH 4 AUTO G ON FALL FAN RELAY 6 H1 ANTICIPATOR H1 R W 8 RISE REVERSING VALVE W2 SYSTEM SWITCH C1 9 C1 ANTICIPATOR COMPRESSOR FAULT LED (RED) OFF 10 COMPRESSOR FAULT A AUTO 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M18587 Fig. 181. Schematic and hookup of T874K with Q674C.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE O 1 H1 ANTICIPATOR FALL SYSTEM COMPONENTS 2 H1 COOL CHANGEOVER VALVE FAN SWITCH AUTO G ON 2BH FAN RELAY 4 R H2 ANTICIPATOR O. D. S. FALL 1BH SH 6 H2 E SYSTEM SWITCH RISE L1 8 EM. HT. LED (RED) CO C1 ANTICIPATOR 9 X EM. HT. AUX. HT. LED (GREEN) ON 10 COMPRESSOR FAILURE 1BH W OFF RISE Y C1 COMPRESSOR CONTACTOR 1 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 L2 (HOT) H1 ANTICIPATOR HEAT RELAY 1 1 W1 FALL AUTO FAN SWITCH H1 G ON FAN RELAY RC W2 4 HEAT RELAY 2 H2 ANTICIPATOR FALL SYSTEM SWITCH 6 H2 RH IGNITION RELAY OFF RISE C1 8 HEAT 9 AUTO C1 ANTICIPATOR 10 B COMPRESSOR CONTACTOR 1 COOL C2 ANTICIPATOR RISE Y1 Y2 11 COMPRESSOR CONTACTOR 2 C2 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS R4 FALL HEAT RELAY 2 H1 R3 2 FAN SWITCH H1 ANTICIPATOR HEAT RELAY 1 R2 HIGH 3 HI SPEED FAN RELAY LOW R1 4 H2 ANTICIPATOR C HIGH TEMP. SWITCH HIGH PRESSURE SWITCH LO SPEED FAN RELAY LR COOL CONTACTOR LOCKOUT RELAY 5 R5 FALL H2 SYSTEM SWITCH RISE C1 8 X 1 L2 HEAT R L1 (HOT) OFF C1 ANTICIPATOR COOL 1 10 POWER SUPPLY. PROVIDE DISCONNECT MEANS M3956 AND OVERLOAD PROTECTION AS REQUIRED. Fig. 187.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS FALL H1 1 B W1 4 5 FALL M839 MOTOR NO FAN SWITCH ANTICIPATOR H2 L1 6 W2 Y RH R L2 NO SYSTEM SWITCH RC 8 Y2 9 Y1 10 11 M3960 Fig. 189. Schematic and hookup of T874F with Q674D. Used in standard applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE 2 FALL H1 C1 H1/C1 ANTICIPATOR 3 SYSTEM COMPONENTS FAN SWITCH Z AUTO LO O "Z" RELAY COOL CHANGEOVER VALVE HI G CONT. L2 FAN RELAY R 4 H2 ANTICIPATOR FALL AUX. HT. RELAY 6 H2 L1 (HOT) 1 W2 C SYSTEM SWITCH W1 HEAT RELAY HEAT OFF COOL COOL RELAY Y 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M3965 Fig. 191. Schematic and hookup of T874R with Q674B. Used in heat pump applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SYSTEM COMPONENTS SUBBASE THERMOSTAT H1 ANTICIPATOR FAN SWITCH 1 L1 (HOT) L2 RH AUTO FALL W1 H1 ON 1 HEAT RELAY 1 4 W2 6 B HEAT RELAY 2 H2 FALL H2 ANTICIPATOR CHANGEOVER RELAY (HEAT) O SYSTEM SWITCH 8 RISE G HEAT C1 CHANGEOVER RELAY (COOL) 2 OFF FAN RELAY 9 AUTO Y2 COOL COMPRESSOR CONTACTOR 2 10 C1 ANTICIPATOR Y1 C2 ANTICIPATOR 11 RC C2 RISE 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) L2 1 COOL CHANGEOVER VALVE H1 ANTICIPATOR O 1 H1 FAN SWITCH FAN RELAY FALL 2 G AUTO "B" RELAY ON B 4 R H2 H2 ANTICIPATOR FALL 6 SYSTEM SWITCH EM. HT. RELAY E OFF 8 L EM. HT. CO RISE HEAT 9 C1 ANTICIPATOR AUTO COOL EM. HT. LED (RED) X AUX. HT. LED (GREEN) 10 W2 AUX. HT. RELAY Y COMPRESSOR CONTACTOR C1 RISE 1 COMPRESSOR FAULT POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS G 1 FAN RELAY W 2 AUTO H1 AUX. HT. LED (GREEN) U 2 AUX. HEATER RELAY ON C1 B 3 FALL FAN SWITCH EM. HT. LED (RED) COMPRESSOR MONITOR F 1 4 L1 (HOT) L2 R H2 5 FALL SYSTEM SWITCH T EM. HT. 6 HEAT OUTDOOR THERMISTOR X2 OFF 11 OUTDOOR THERMOSTAT COOL O 1 COMPRESSOR RELAY POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SYSTEM COMPONENTS SUBBASE THERMOSTAT L1 (HOT) L2 1 W3 RELAY H1 ANTICIPATOR 2 W3 FAN SWITCH FAN RELAY H1 AUTO FALL G 3 ON R 4 H2 W2 H2 ANTICIPATOR FALL 5 AUX. HT. RELAY SYSTEM SWITCH AUX. HT. LED (GREEN) EM. HT. RELAY E EM. HT. LED (RED) OFF COMPRESSOR FAULT 8 CO EM. HT. RISE CHECK LED (RED) 9 HEAT 10 COOL AUTO B C1 ANTICIPATOR C1 L X HEAT CHANGEOVER VALVE 11 O RISE COOL CHANGEOVER RELAY 12 Y 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT C1 1 H2 ANTICIPATOR RISE T OUTDOOR THERMOSTAT FAN SWITCH 2 AUTO 3 ON OUTDOOR THERMOSTAT FAN RELAY G 5 H2 SERVICE LED (YELLOW) C1 ANTICIPATOR SYSTEM SWITCH 6 EM. HEAT 11 R X HEAT SERVICE Z OFF K COMPRESSOR CONTACTOR EM. HT. LED (RED) COOL H1 ANTICIPATOR SEQ 1 Y 12 HEAT CHANGEOVER VALVE W1 1 SEQ 2 W2 4 RISE L1 (HOT) L2 1 C815A OUTDOOR THERMISTOR RESET H1 SYSTEM COMPONENTS POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS COMPRESSOR CONTACTOR Y CO L1 (HOT) L2 1 FAN SWITCH FALL FAN RELAY 2 3 AUTO G ON R HEAT CHANGEOVER VALVE 4 W H1 6 H1 ANTICIPATOR FALL SYSTEM SWITCH COMP. FAULT (RED) 8 OFF C1 RISE W2 9 COMPRESSOR FAULT A AUTO 10 C1 ANTICIPATOR 1 M2981 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. Fig. 203. Schematic and hookup of T874L with Q674C. Used in heat pump applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS L1 (HOT) L2 1 COOL CHANGEOVER VALVE H1 ANTICIPATOR 2 Y1 H1 COMPRESSOR CONTACTOR FALL 3 Y2 FAN SWITCH FAN RELAY AUTO 4 G ON R 6 L 8 CO RISE SYSTEM SWITCH LED (RED) X1 OFF 9 C AUTO C1 ANTICIPATOR C1 RISE LED (RED) 10 2 X2 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 LEDS ON SOME MODELS. M2983 Fig. 205. Schematic and hookup of T874H with Q674C.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS R 2 H1 FAN SWITCH H1 ANTICIPATOR FALL L1 (HOT) L2 1 COMPRESSOR CONTACTOR Y 3 AUTO 4 ON FAN RELAY H2 ANTICIPATOR G H.C.R.1 5 H2 W2 FALL 6 CO RISE SUPL. HT. LED (RED) SYSTEM SWITCH 8 O.D.T. L SUPL. HT. 9 C1 ANTICIPATOR 10 HEAT C OFF E COOL H.C.R.1 H.C.R.2 H.C.R.2 H.C.R.3 11 O 12 RISE 1 CO C1 COOL CHANGEOVER VALVE POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS R EM. HT. RELAY EM. HT. LED (RED) H1 L C1 FAN SWITCH H1/C1 ANTICIPATOR RISE L1 (HOT) L2 1 2 AUTO 3 ON AUX. HT. LED (GREEN) X AUX. HT. RELAY W2 FAN RELAY 4 G 6 COOL CHANGEOVER VALVE SYSTEM SWITCH H2 ANTICIPATOR H2 EM. HEAT O EM. HT. RELAY HEAT FALL E OFF COMPRESSOR CONTACTOR COOL Y ’"B" RELAY M2987 B POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 1 Fig. 209.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS L1 (HOT) L2 1 W1 RELAY H1 ANTICIPATOR 2 W1 FAN SWITCH H1 FALL FAN RELAY AUTO G 3 ON R AUX. HT. RELAY SYSTEM SWITCH 4 W2 AUX. HT. LED (GREEN) OFF H2 H2 ANTICIPATOR FALL 6 EM. HT. X HEAT 8 EM. HT. LED (RED) AUTO RISE C1 ANTICIPATOR C1 L COMPRESSOR FAULT COOL 10 Y1 1 COMPRESSOR CONTACTOR POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M2989 Fig. 211.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS L1 (HOT) L2 1 1 2 H1 H1 ANTICIPATOR FALL SYSTEM SWITCH RELAY 1 N.O. 2 OFF H1 3 AUTO COMPRESSOR CONTACTOR 4 H2 R FALL C 7 8 FAN SWITCH FIELD REMOVABLE JUMPER AUX. HT. RELAY H2 LO CO 9 10 C1 ANTICIPATOR S1 RELAY N.C. Y 5 H2 ANTICIPATOR RISE S1 RELAY MED L CHECK LED (RED) R1 RELAY N.C. 1 COMPRESSOR CONTACTOR HIGH ON R2 RELAY N.O 1 COOL CHANGEOVER VALVE O R1 RELAY K1 RELAY 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT H1 SYSTEM COMPONENTS L1 (HOT) L2 1 1 FALL SYSTEM SWITCH HEAT H1 ANTICIPATOR 2 AUX. HT. RELAY H1 OFF R C1 ANTICIPATOR R1 RELAY COOL O 3 4 C1 RISE 5 COOL CHANGEOVER VALVE L FAN SWITCH R2 RELAY N.O. 1 LO COMPRESSOR CONTACTOR MED C HIGH CHECK LED (RED) ON COMPRESSOR CONTACTOR 11 S1 RELAY N.C. Y 12 1 K1 RELAY POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. G1 K2 RELAY G2 M2992 Fig. 214.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS L1 (HOT) L2 1 1 2 H1 H1 ANTICIPATOR FALL SYSTEM SWITCH RELAY 1 N.O. 2 HEAT S1 RELAY H1 3 OFF COMPRESSOR CONTACTOR 4 S1 RELAY N.C. COOL H2 Y 5 H2 ANTICIPATOR R FALL C 7 8 FIELD REMOVABLE JUMPER FAN SWITCH AUX. HT. RELAY H2 LO RISE C1 9 10 C1 ANTICIPATOR L MED CHECK LED (RED) R1 RELAY N.C. 1 COMPRESSOR CONTACTOR HIGH ON R2 RELAY N.O.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS COOL CHANGEOVER VALVE O H1 ANTICIPATOR H1 FALL G FAN SWITCH 1 FAN RELAY L2 AUTO 1 L1 (HOT) ON 2 R 3R 4 SEQ 2 W1 6 FALL AUX. HT. LED (YELLOW) H2 SEQ 1 2 E H2 ANTICIPATOR SYSTEM SWITCH X RISE EM. HT. AUTO CO 9 OFF 5R C SYSTEM LED (GREEN) 10 RISE 4R CHECK LED (RED) 8 C1 EM. HT. RELAY 4R HPS C1 ANTICIPATOR 4R Y 1 COMPRESSOR POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SYSTEM COMPONENTS SUBBASE L1 (HOT) R L2 L 2 H1/C1 ANTICIPATOR 3 EM. HT. LED (RED) 3 FAN SWITCH C1 FALL 4 2 ON X H2 ANTICIPATOR H2 FALL AUX. HT. RELAY W3 AUTO H1 1 AUX. HT. LED (GRN) 6 AUX. HT. RELAY W2 SYSTEM SWITCH EM. HT. FAN RELAY G HEAT COOL CHANGEOVER VALVE OFF O COOL E EM. HT. RELAY Y COMPRESSOR CONTACTOR B 1 "B" RELAY POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS CONTROL MODULE 1 W1 H1 HEAT RELAY 1 2 FALL W2 H1 ANTICIPATOR HEAT RELAY 2 W3 SYSTEM SWITCH OFF 4 AUTO 5 Y2 6 A FALL H2 ANTICIPATOR 3 SERVICE LED (RED) 7 FAN SWITCH FAN RELAY G H2 AUTO C1 RISE 8 L1 (HOT) R ON L2 1 2 9 O MONENTARY CIRCUIT COMPRESSOR CONTACTOR 1 10 Y1 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 MOMENTARY POSITION.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS CONTROL MODULE 1 HEAT RELAY #1 SYSTEM SWITCH H1 FALL OFF 2 H1 ANTICIPATOR W1 HEAT RELAY #2 W2 AUTO HEAT RELAY #3 4 W3 COMPRESSOR CONTACTOR #2 5 Y2 FALL H3 SYSTEM MONITOR H2 ANTICIPATOR H2 6 A SERVICE LED (RED) FALL FAN RELAY G 7 L2 RISE C1 8 FAN SWITCH AUTO ON 1 MOMENTARY CIRCUIT O 9 2 10 COMPRESSOR CONTACTOR #1 Y1 RISE C2 L1 (HOT) R 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SUBBASE THERMOSTAT SYSTEM COMPONENTS L1 (HOT) R H1 ANTICIPATOR L2 2 FALL H1 3 4 SYSTEM MONITOR FAN SWITCH 1 L FAN RELAY AUTO G ON W 8 MALFUNCTION LED (RED) SYSTEM SWITCH HEAT RELAY C C1 RISE 9 C1 ANTICIPATOR HIGH SPEED LED (YELLOW) OFF LOW SPEED LED (GREEN) HEAT 10 AUTO C2 ANTICIPATOR C2 11 COMPRESSOR CONTACTOR 1 Y1 COOL COMPRESSOR CONTACTOR 2 RISE Y2 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS CONTROL MODULE FALL 1 HEAT CHANGEOVER VALVE H1 B HEAT RELAY #1 H1 ANTICIPATOR W1 COMPRESSOR CONTACTOR #1 4 Y1 FAN SWITCH AUTO FAN RELAY G H2 ANTICIPATOR ON L1 (HOT) L2 1 RC H2 6 FALL HEAT RELAY #2 W2 8 SYSTEM SWITCH RH OFF C1 SERVICE LED (RED) RISE 9 HEAT L1 (HOT) L2 1 SYSTEM MONITOR A AUTO 10 COOL COMPRESSOR CONTACTOR #2 Y2 11 C2 COOL CHANGEOVER VALVE RISE O 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS CONTROL MODULE HEAT RELAY #1 FALL 1 W1 HEAT RELAY #2 H1 W2 FAN SWITCH H1 ANTICIPATOR HEAT DAMPER B AUTO 4 ON L1 (HOT) RH L2 H2 ANTICIPATOR 6 1 L2 1 L1 (HOT) RC H2 COOL DAMPER FALL O 8 SYSTEM SWITCH FAN RELAY G C1 RISE 9 COMPRESSOR CONTACTOR #2 OFF Y2 AUTO 10 COMPRESSOR CONTACTOR #1 11 Y1 C2 1 SERVICE LED (RED) RISE SYSTEM MONTIOR A POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS CONTROL MODULE SYSTEM MONITOR A2 FALL SERVICE LED (RED) H1 NO FAN SWITCH H1 ANTICIPATOR HEAT RELAY #1 W1 1 SERVICE LED (RED) SYSTEM MONITOR A1 HEAT RELAY #2 4 W2 T RELAY 5 T 6 H2 L1 (HOT) 1 L2 RC H2 FALL ANTICIPATOR SYSTEM SWITCH FAN RELAY B B 7 OFF 8 L2 L1 1 (HOT) AUTO RH C1 RISE FAN RELAY O 9 O COMPRESSOR CONTACTOR #2 10 Y2 11 COMPRESSOR CONTACTOR #1 C2 RISE 1 12 Y1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE 1 CO (HEAT) FAN SWITCH W3 RELAY W3 AUTO 2 FALL SYSTEM COMPONENTS H1 ANTICIPATOR FAN RELAY G ON 3 R AUX. HT. RELAY 4 FALL 1 L2 L1 (HOT) W2 H2 EM. HT. RELAY 5 E H2 ANTICIPATOR AUX. HT. LED (GREEN) H1 FALL 6 CO (COOL) SYSTEM SWITCH 8 OFF 9 EM. HT. RISE COMPRESSOR FAULT X1 CHECK LED (RED) X2 HEAT EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 L2 (HOT) 1 R 1 H1 FAN SWITCH C1 FALL Y1 2 COMP. RELAY AUTO O.L. IN. STAT. HI. PRO. G H1/C1 ANTICIPATOR ON 3 FAN RELAY L SENSOR LED (RED) 4 H2 ANTICIPATOR SERVICE 2 5 EM. HT. H2 EM. HT. RELAY O.D.S. W1 FALL SYSTEM SWITCH 6 EM. HT. E AUX. HT. LED (GREEN) ELECTRIC HEAT RELAY ELECTRIC HEAT RELAY EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS L1 (HOT) L2 R 1 FAN SWITCH H1 ANTICIPATOR 2 COMP. RELAY IN. STAT. O.L. 1 HI. PRO Y1 AUTO H2 ANTICIPATOR ON 3 G FAN RELAY H1 SERVICE LED (RED) 4 FALL L SERVICE 5 FALL H2 O.D.S. 2 6 SYSTEM SWITCH OFF 8 RISE EM. HT. RELAY W1 RESET CO AUX. HT. LED (GREEN) EM. HT. 9 C1 ANTICIPATOR ELECTRIC HT. RELAY EM. HT. E EM. HT. LED (YELLOW) ELECTRIC HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 2 H1 O H1 ANTICIPATOR FALL 3 COOL CHANGEOVER VALVE L FAN SWITCH COMPRESSOR FAULT EM. HT. LED (RED) AUTO 4 ON 1 H2 ANTICIPATOR SYSTEM SWITCH 8 E X AUX. HT. LED (GREEN) OFF EM. HT. 9 HEAT 10 2 AUTO W3 RELAY 11 W3 COMPRESSOR RELAY 12 RISE HEAT CHANGEOVER VALVE B COOL RISE CO AUX. HT. RELAY W2 C1 ANTICIPATOR H1 L2 EM. HT. RELAY FALL C1 L1 (HOT) R 5 H2 FAN RELAY G Y 1 POWER SUPPLY.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT FALL H1 SUBBASE H1 ANTICIPATOR SYSTEM COMPONENTS 1 COMPRESSOR HIGH SPEED Y1 H2 ANTICIPATOR 2 3 FALL AUTO FAN G 4 ON H3 H3 ANTICIPATOR AUX. HT. W2 R 5 FAN SWITCH FALL 6 H2 EM. HT. RISE C1 W89 HEAT PUMP CONTROL PANEL B EM. HT. C1 ANTICIPATOR RISE C2 E SYSTEM SWITCH 8 C2 ANTICIPATOR 9 HEAT EM. HT. LED (YELLOW) EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS H1 ANTICIPATOR R 2 RTD1 L1 (HOT) OTD1 FAN SWITCH L2 1 3 FALL H1 W2 ON 4 ODT2 H2 ANTICIPATOR EHR2 AUX. HT. LED (GRN) 5 SYSTEM SWITCH H2 FALL EM. HT. LED (RED) OFF RTD3 RTD1 X SYSTEM MONITOR 8 COOL FAN RELAY L 9 RISE RTD2 EHR1 AUTO AUTO G HEAT C1 ANTICIPATOR CHANGEOVER RD COOL CHANGEOVER VALVE EM. HT. 10 O RISE EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES SYSTEM COMPONENTS SUBBASE THERMOSTAT H1 ANTICIPATOR L1 (HOT) L2 R 1 FAN SWITCH 1 AUTO 2 FAN RELAY ON FALL G 3 H2 ANTICIPATOR H1 B 4 LOW LED (YELLOW) 5 SYSTEM SWITCH H2 FALL 6 HEAT HI LED (GREEN) 8 C1 HEAT 1 W1 HEAT 2 OFF W2 RISE COOL 10 COMPRESSOR CONTACTOR C1 ANTICIPATOR Y 1 M7716 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. Fig. 237. Schematic and hookup of T874C with Q674B.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 1 G FAN RELAY H1 ANTICIPATOR W FAN SWITCH 2 AUX. HT. LED (GREEN) AUTO H1 ON EM. HT. LED (RED) FALL C1 H2 2 B COMPRESSOR MONITOR 3 F 4 R FALL 5 SYSTEM SWITCH 6 EM. HT. AUX. HT. RELAY U L1 (HOT) OUTDOOR SENSOR L2 1 T HEAT X2 OFF COOL 11 O RESET 1 COOL CHANGEOVER OUTDOOR VALVE THERMOSTAT COMPRESSOR CONTACTOR POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 2 H1 ANTICIPATOR L2 FAN SWITCH 3 H1 L1 (HOT) R AUTO 4 FALL 1 Y ON FAN RELAY COMPRESSOR CONTACTOR G H2 ANTICIPATOR 5 W2 6 H2 HEAT CHANGEOVER VALVE NO. 1 SUPL. HEAT LED (RED) L C FALL 8 SYSTEM SWITCH C1 ANTICIPATOR SUPL. HT. 9 CO E HEAT HEAT CHANGEOVER VALVE NO. 2 10 RISE HEAT HEAT CHANGEOVER CHANGEOVER VALVE NO. 2 VALVE NO. 1 O.D.T. OFF 11 COOL HEAT CHANGEOVER VALVE NO.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 1 FALL H1 ANTICIPATOR O FAN SWITCH COOL CHANGEOVER VALVE AUTO 2 G ON FAN RELAY H1 B B RELAY 4 L1 (HOT) R 6 SYSTEM SWITCH H2 ANTICIPATOR L2 E OFF EM. HT. H2 FALL 1 EM. HT. RELAY L EM. HT. LED (RED) HEAT AUTO RISE 8 C1 2 X COOL AUX. HEAT LED (GREEN) AUX. HEAT RELAY 9 W2 C1 ANTICIPATOR Y 10 11 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT H1/C1 ANTICIPATOR SUBBASE 2 SYSTEM COMPONENTS O FAN SWITCH COOL CHANGEOVER VALVE AUTO 3 G H1 ON FAN RELAY C1 FALL B B RELAY L1 (HOT) R 4 6 H2 ANTICIPATOR L2 SYSTEM SWITCH E EM. HT. L HEAT EM. HT. LED (RED) OFF FALL 1 EM. HT. RELAY 2 H2 X COOL AUX. HT. LED (GREEN) AUX. HT. RELAY 1 W2 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 1 FALL H1 ANTICIPATOR T H1 2 C815A OUTDOOR THERMISTOR H2 W3 H2 ANTICIPATOR FALL AUX. HT. RELAY 3 AUX. HEAT LED (GREEN) FAN SWITCH AUTO H3 ANTICIPATOR 4 G ON FAN RELAY H3 L1 (HOT) L2 1 R FALL 5 EM. HEAT LED (RED) E 6 EM. HT. RELAY RESET X1 CHECK LED (YELLOW) C CHANGEOVER RELAY (HEAT) RISE 8 C1 SYSTEM SWITCH CHANGEOVER RELAY (COOL) EM.HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS 2 FALL H1 H1 ANTICIPATOR 3 4 H2 L1 (HOT) R FAN SWITCH L2 AUTO 1 ON L H2 ANTICIPATOR FAN RELAY G FALL AUX. HT. RELAY 5 W2 7 E RISE C1 AUX. HT. LED (RED) 8 SYSTEM SWITCH 9 OFF MALFUNCTION LED (RED) EM.HT. RELAY C HIGH SPEED LED (YELLOW) EM. HT.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES THERMOSTAT SUBBASE SYSTEM COMPONENTS HEAT RELAY 1 FALL W1 H1 1 H1 ANTICIPATOR FAN SWITCH FAN RELAY G AUTO 3 ON RC 2 HEAT RELAY 2 4 W2 6 HEAT DAMPER FALL B H2 ANTICIPATOR H2 SERVICE LED (RED) C X 8 L1 (HOT) 1 L2 SYSTEM SWITCH RH C1 HEAT RISE 9 OFF COOL DAMPER O COOL C1 ANTICIPATOR 10 COMPRESSOR CONTACTOR 1 Y1 C2 ANTICIPATOR RISE COMPRESSOR CONTACTOR 2 11 Y2 C2 1 POWER SUPPLY.