Operating instructions

ManualsBrandsBryant ManualsFurnace355MAV

NOTE: Read the entire instruction manual before starting the

installation.

This symbol → indicates a change since the last issue.

Index Page

SAFETY CONSIDERATIONS.....................................................2

DIMENSIONAL DRAWING........................................................3

Clearances to Combustibles......................................................4

CODES AND STANDARDS........................................................5

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS........5

INTRODUCTION..........................................................................6

APPLICATIONS............................................................................6

General ......................................................................................6

Upflow Applications.................................................................6

Downflow Applications............................................................8

Horizontal Left (Supply-Air Discharge) Applications ..........10

Horizontal Right (Supply-Air Discharge) Applications ........12

LOCATION..................................................................................13

General ....................................................................................13

Low-Heat Only Installation....................................................14

Furnace Location Relative to Cooling Equipment ................15

Hazardous Locations...............................................................15

INSTALLATION.........................................................................15

Leveling Legs (If Desired).....................................................15

Installation In Upflow or Downflow Applications................15

Installation In Horizontal Applications..................................17

Air Ducts.................................................................................18

General Requirements .......................................................18

Ductwork Acoustical Treatment .......................................18

Supply Air Connections ....................................................18

Return Air Connections.....................................................18

Filter Arrangement..................................................................18

Bottom Closure Panel.............................................................19

Gas Piping...............................................................................19

Electrical Connections ............................................................20

115-v Wiring......................................................................20

24-v Wiring........................................................................22

Accessories ........................................................................22

Direct Venting.........................................................................22

Removal of Existing Furnaces from

Common Vent Systems................................................22

Combustion-Air and Vent Piping .....................................25

Concentric Vent and Combustion-Air Termination

Kit Installation..............................................................31

Multiventing and Vent Terminations................................34

Condensate Drain....................................................................34

General...............................................................................34

Application.........................................................................34

Condensate Drain Protection.............................................35

START-UP, ADJUSTMENTS AND SAFETY CHECK......35

General...............................................................................35

Select Setup Switch Positions...........................................36

Prime Condensate Trap With Water.................................37

Purge Gas Lines ................................................................37

Sequence of Operation ......................................................37

Single-Stage Thermostat and Two-Stage Heating

(Adaptive Mode) ..........................................................37

Two-Stage Thermostat and Two-Stage Heating.........39

Cooling Mode ...............................................................39

Thermidistat Mode.......................................................40

Super-Dehumidify Mode..............................................40

Continuous Blower Mode............................................40

Heat Pump....................................................................41

Component Test ...........................................................41

Adjustments .......................................................................41

Set Gas Input Rate.......................................................41

Set Temperature Rise...................................................48

Set Thermostat Heat Anticipator.................................49

A93040

ama

CERTIFIED

REGISTERED

ISO 9001:2000

As an ENERGY STAR®

Partner, Bryant Heating &

Cooling Systems has de-

termined that this product

meets the ENERGY

STAR® guidelines for en-

ergy efficiency.

Fig. 1—Multipoise Orientations

A93041

UPFLOW

DOWNFLOW

HORIZONTAL

LEFT

AIRFLOW

HORIZONTAL

RIGHT

installation, start-up,

and operating instructions

DELUXE 4-WAY MULTIPOISE

VARIABLE-CAPACITY DIRECT-VENT

CONDENSING GAS FURNACE

Cancels: II 355M-40-13 II 355M-40-14

3-05

355MAV

Series I

—1—

Summary of content (52 pages)

PAGE 1
installation, start-up, and operating instructions 355MAV Series I DELUXE 4-WAY MULTIPOISE VARIABLE-CAPACITY DIRECT-VENT CONDENSING GAS FURNACE Cancels: II 355M-40-13 ama II 355M-40-14 3-05 CERTIFIED ® ISO 9001:2000 A93040 NOTE: Read the entire instruction manual before starting the installation. This symbol → indicates a change since the last issue. Index Page SAFETY CONSIDERATIONS .....................................................2 DIMENSIONAL DRAWING..........................................
PAGE 2
Check Safety Controls.......................................................49 Check Primary Limit Control ......................................49 Check Pressure Switch.................................................49 CHECKLIST......................................................................49 → SAFETY CONSIDERATIONS CAUTION: FURNACE RELIABILITY HAZARD Improper installation or misapplication of furnace may require excessive servicing or cause premature component failure.
PAGE 3
—3— 11⁄4" 1" 14 1⁄2" TYP 26 15⁄16" 1⁄2-IN. UNIT SIZE 042040* 042060 042080 060080 060100 060120 11/16" E INLET OUTLET D A AIRFLOW 11/16" 18 1⁄4" A 24-1/2* 17-1/2 21 21 21 24-1/2 DIMENSIONS (IN.) Fig. 2—Dimensional Drawing D 22-7/8* 15-7/8 19-3/8 19-3/8 19-3/8 22-7/8 TYP 9⁄16" DIMPLE LOCATORS FOR HORIZONTAL HANGING CONDENSATE DRAIN LOCATION (UPFLOW) 30 1⁄2" CONDENSATE DRAIN TRAP LOCATION (DOWNFLOW & HORIZONTAL RIGHT) OR ALTERNATE 1⁄2-IN. DIA GAS CONN 13/16" NOTES: 1.
PAGE 4
This furnace must be installed with a direct-vent (combustion air and flue) system and a factory accessory termination kit. In a direct-vent system, all air for combustion is taken directly from the outside atmosphere and all flue products are discharged to the outside atmosphere. See furnace and factory accessory termination kit instructions for proper installation.
PAGE 5
0 18-IN. MINIMUM TO BURNERS 60 A93044 V. • A05004 → → For Fig. 4—Return-Air Temperature accessory installation details, refer to accessory installation instructions. Fig. 5—Installation in a Garage ACOUSTICAL LINING AND FIBROUS GLASS DUCT US and CANADA: current edition of SMACNA, NFPA 90B as tested by UL Standard 181 for Class I Rigid Air Ducts VI.
PAGE 6
FURNACE DOOR BLOWER SHELF CONDENSATE TRAP CONDENSATE TRAP (INSIDE) FURNACE DOOR FURNACE SIDE 4 78 FURNACE SIDE 4 534 534 4 FIELD DRAIN CONN ALTERNATE DRAIN TUBE LOCATION 26 1 4 26 1 4 11 2 SIDE VIEW CONDENSATE TRAP DRAIN TUBE LOCATION FIELD DRAIN CONN FRONT VIEW END VIEW SLOT FOR SCREW HORIZONTAL APPLICATION (OPTIONAL) FRONT VIEW HORIZONTAL APPLICATIONS DOWNFLOW AND ALTERNATE EXTERNAL UPFLOW APPLICATIONS UPFLOW APPLICATIONS 34 1⁄4 OD COLLECTOR BOX TO TRAP RELIEF PORT 11 2 1⁄2 OD
PAGE 7
PLUG PLUG CAP CAP COLLECTOR BOX DRAIN TUBE (BLUE & WHITE STRIPED) COLLECTOR BOX DRAIN TUBE (BLUE & WHITE STRIPED) COLLECTOR BOX TUBE (PINK) COLLECTOR BOX TUBE (PINK) COLLECTOR BOX TUBE (GREEN) COLLECTOR BOX DRAIN TUBE (GREEN) INDUCER HOUSING (MOLDED) DRAIN TUBE (BEHIND COLLECTOR BOX DRAIN TUBE) COLLECTOR BOX DRAIN TUBE (BLUE) COLLECTOR BOX TUBE (GREEN) CONDENSATE TRAP CONDENSATE TRAP INDUCER HOUSING DRAIN TUBE (VIOLET) FIELD-INSTALLED FACTORY-SUPPLIED DRAIN TUBE COUPLING (LEFT DRAIN OPTION) FIELD-
PAGE 8
UPPER INDUCER HOUSING DRAIN CONNECTION 3. Install casing hole filler cap (factory-supplied in loose parts bag) into blower shelf hole where trap was removed. → Attached to the UPPER (unused) inducer housing drain connection is a cap and clamp. This cap is used to prevent condensate leakage in this application. Ensure this connection is capped. WARNING: CARBON MONOXIDE POISONING HAZARD Failure to follow this warning could result in personal injury or death.
PAGE 9
COLLECTOR BOX DRAIN TUBE (BLUE) CAP COLLECTOR BOX TUBE (GREEN) PLUG PLUG CAP COLLECTOR BOX TUBE (GREEN) COLLECTOR BOX DRAIN TUBE (BLUE) COLLECTOR BOX TUBE (PINK) COLLECTOR BOX TUBE (PINK) COLLECTOR BOX DRAIN TUBE (BLUE & WHITE STRIPED) COLLECTOR BOX DRAIN TUBE (BLUE & WHITE STRIPED) COLLECTOR BOX EXTENSION TUBE COLLECTOR BOX EXTENSION TUBE INDUCER HOUSING DRAIN TUBE (VIOLET) CONDENSATE TRAP CONDENSATE TRAP COLLECTOR BOX EXTENSION DRAIN TUBE INDUCER HOUSING DRAIN TUBE (VIOLET) DRAIN TUBE COUPLING
PAGE 10
PLUG CAP COLLECTOR BOX DRAIN TUBE (BLUE AND WHITE STRIPED) AUXILIARY "J" BOX CONDENSATE TRAP COLLECTOR BOX TUBE (GREEN) INDUCER HOUSING DRAIN TUBE (VIOLET) COLLECTOR BOX EXTENSION TUBE COLLECTOR BOX DRAIN TUBE (BLUE) COLLECTOR BOX EXTENSION DRAIN TUBE DRAIN TUBE COUPLING COLLECTOR BOX TUBE (PINK) RELOCATE TUBE BETWEEN BLOWER SHELF AND INDUCER HOUSING FOR 060, AND 080 HEATING INPUT FURNACES A02288 Fig. 11—Horizontal Left Tube Configuration 2.
PAGE 11
COMBUSTION – AIR INTAKE VENT 30″ MIN WORK AREA 5 3⁄4″ MANUAL SHUTOFF GAS VALVE A 12-IN. MIN HORIZONTAL PIPE SECTION IS RECOMMENDED WITH SHORT (5 TO 8 FT) VENT SYSTEMS TO REDUCE EXCESSIVE CONDENSATE DROPLETS FROM EXITING THE VENT PIPE. ACCESS OPENING FOR TRAP SEDIMENT TRAP DRAIN CONDENSATE TRAP NOTE: LOCAL CODES MAY REQUIRE A DRAIN PAN UNDER THE FURNACE AND CONDENSATE TRAP WHEN A CONDENSING FURNACE IS INSTALLED ABOVE FINISHED CEILINGS. A93031 Fig. 12—Attic Location and Working Platform → b.
PAGE 12
CAP COLLECTOR BOX DRAIN TUBE (BLUE) COLLECTOR BOX TUBE (GREEN) PLUG COLLECTOR BOX TUBE (PINK) AUXILIARY "J" BOX RELOCATED HERE CONDENSATE TRAP COLLECTOR BOX DRAIN TUBE (BLUE AND WHITE STRIPED) INDUCER HOUSING DRAIN TUBE (VIOLET) COLLECTOR BOX EXTENSION TUBE A02289 Fig. 13—Horizontal Right Tube Configuration 3. Route extended tube: CAUTION: MINOR PROPERTY DAMAGE Failure to follow this caution may result in minor property damage.
PAGE 13
→ NOTE: See Fig. 13 or tube routing label on main furnace door to check for proper connections. Relocate tubes as described below. WARNING: CARBON MONOXIDE POISONING HAZARD Failure to follow this warning could result in personal injury or death. Casing hole filler cap must be installed in blower shelf hole when condensate trap is relocated to prevent combustion products being drawn in from appliances in the equipment room. 1.
PAGE 14
FRONT LEVEL (0″) TO 1⁄2″ MAX FRONT UPFLOW OR DOWNFLOW MIN 1⁄4″ TO 1⁄2″ MAX FRONT B A C K HORIZONTAL BACK A02146 Fig. 14—Proper Condensate Drainage FRONT NOTE: For upflow/downflow applications install furnace so that it is level or pitched forward within 1/2-in. for proper furnace operation. For horizontal applications pitch 1/4-in. minimum to 1/2-in. maximum forward to ensure proper condensate drainage from secondary heat exchangers. (See Fig. 14.) A93043 Fig.
PAGE 15
INSTALLATION I. LEVELING LEGS (IF DESIRED) When furnace is used in upflow position with side inlet(s), leveling legs may be desired. (See Fig. 18.) Install field-supplied, corrosion-resistant 5/16-in. machine bolts and nuts. NOTE: The maximum length of bolt should not exceed 1-1/2 in. 1. Position furnace on its back. Locate and drill a 5/16-in. diameter hole in each bottom corner of furnace. (See Fig. 18.) Holes in bottom closure panel may be used as guide locations.
PAGE 16
A PLENUM OPENING D B FLOOR OPENING C A96283 Fig. 19—Floor and Plenum Opening Dimensions FURNACE FURNACE (OR COIL CASING WHEN USED) CD5 OR CK5 COIL ASSEMBLY OR KCAKC COIL BOX COMBUSTIBLE FLOORING COMBUSTIBLE FLOORING DOWNFLOW SUBBASE SHEET METAL PLENUM SHEET METAL PLENUM FLOOR OPENING FLOOR OPENING A96284 A96285 Fig. 21—Furnace, Plenum, and Coil Assembly or Coil Box Installed on a Combustible Floor Fig.
PAGE 17
CAUTION: UNIT MAY NOT OPERATE Failure to follow this caution may result in intermittent unit operation or performance satisfaction. Do not bend duct flanges inward as shown in Fig. 22. This will affect airflow across heat exchangers and may cause limit cycling or premature heat exchanger failure. Remove duct flange completely or bend it inward a minimum of 210° as shown in Fig. 22. PERFORATED DISCHARGE DUCT FLANGE NO YES III.
PAGE 18
installed on non-combustible material. When installed on combustible material, supply-air duct attachment must ONLY be connected to an accessory subbase or factory approved air conditioning coil casing. DO NOT cut main furnace casing to attach supplyside air duct, humidifier, or other accessories. All accessories MUST be connected external to furnace main casing. Supply air opening duct flanges must be modified per Fig. 22.
PAGE 19
VII. GAS PIPING Gas piping must be installed in accordance with national and local codes. Refer to NFGC in the U.S. Canadian installations must be made in accordance with NSCNGPIC and all authorities having jurisdiction. Gas supply line should be a separate line running directly from meter to furnace, if possible. Refer to Table 3 for recommended gas pipe sizing. Risers must be used to connect to furnace and to meter.
PAGE 20
straps, hangers, etc. Use a minimum of 1 hanger every 6 ft. Joint compound (pipe dope) should be applied sparingly and only to male threads of joints. Pipe dope must be resistant to propane gas. recommended that ground joint union be loosened before pressure testing. After all connections have been made, purge lines and check for leakage at furnace prior to placing it into service.
PAGE 21
FIELD 24-V WIRING FIELD 115-, 208/230-, 460-V WIRING FACTORY 24-V WIRING FACTORY 115-, 208/230-, 460-V WIRING NOTE 5 W FIVE WIRE C R G THERMOSTAT TERMINALS Y FIELD-SUPPLIED DISCONNECT THREE-WIRE HEATING ONLY 208/230- OR 460-V THREE PHASE W/W1 GND 115-V SINGLE PHASE W2 GND NOTE 3 R AUXILIARY 115-V FIELD-SUPPLIED J-BOX DISCONNECT SWITCH FURNACE CONTROL CENTER 208/230-V SINGLE PHASE G C GND GND NOTE 1 CONDENSING UNIT Y/Y2 TWO WIRE 24-V TERMINAL BLOCK NOTES: 1.
PAGE 22
NOTE: For additional thermostat connection diagrams, reference Fig. 54-61. C. Accessories WARNING: FIRE OR ELECTRICAL SHOCK HAZARD Failure to follow this warning could result in intermittent unit operation or performance satisfaction. If manual disconnect switch is to be mounted on furnace, select a location where a drill or fastener will not contact electrical or gas components. 1. Electronic Air Cleaner (EAC) The furnace control EAC terminals are energized with 115v (1.
PAGE 23
PRINTED CIRCIUT BOARD —23— 1 AB CD OAT 1 PL1 875 8752 700 2 700 1050 1050 875 1225 1225 1400 1400 1050 1 1225 W2 Y1 DHUM G ComY/Y2 W/W1 R 24V A/C Air Conditioning (Adjustable Airflow -CFM) ACR Air Conditioning Relay, SPST (N.O.) ACRDJ Air Conditioning Relay Defeat Jumper BLWM Blower Motor (ECM) CF Continuous Fan (Adjustable Airflow -CFM) COMMR Communication Relay, SPDT CPU Microprocessor / Circuitry DHUM DHUM Connection (24VAC ) EAC-1 Electronic Air Cleaner Connection (115VAC 1.0 Amp Max.
PAGE 24
MODEL PLUG CONNECTOR COMMUNICATION CONNECTOR CONTINUOUS FAN (CF) AIRFLOW SETUP SWITCHES FUTURE APPLICATIONS SW1 SETUP SWITCHES AND BLOWER OFFDELAY AIR CONDITIONING (A/C) AIRFLOW SETUP SWITCHES HUMIDIFIER TERMINAL (24-VAC 0.5 AMP MAX.
PAGE 25
TABLE 5—APPROVED COMBUSTION-AIR AND VENT PIPE, FITTING AND CEMENT MATERIALS ASTM SPECIFICATION MATERIAL PIPE FITTINGS SOLVENT CEMENT AND PRIMERS DESCRIPTION (MARKED ON MATERIAL) D1527 ABS Pipe — — Schedule-40 D1785 PVC Pipe — — Schedule-40 Solvent D2235 For ABS — — For ABS Cement D2241 PVC Pipe — — SDR-21 & SDR-26 D2466 PVC — Fittings — Schedule-40 D2468 ABS — Fittings — Schedule-40 Solvent D2564 For PVC — — For PVC Cement D2661 ABS Pipe Fittings — DWV at Schedule-40 IPS sizes D2665 PVC Pipe Fittings — DWV
PAGE 26
O Y D Y X H M E V P B I V B C X L N V R OPE V D FIXE ED CLOS E RABL OPE G D FIXE ED OS ABLE CL B X K V A B J B F A 25--24--65--2 B V Item X AIR SUPPLY INLET VENT TERMINAL Clearance Description AREA WHERE TERMINAL IS NOT PERMITED U.S.
PAGE 27
NOTE: Do not count elbows or pipe sections in terminations or within furnace. See shaded areas in Fig. 37, 38, 39, 40, and 41. NOTE: Select 1 vent pipe connection and NOTE: Select 1 vent pipe connection and 1 combustion-air pipe connection. 1 combustion-air pipe connection.
PAGE 28
12″ MIN 12″ MIN VENT PIPE VENT PIPE COMBUSTION-AIR PIPE HORIZONTAL TO ROOF COMBUSTION-AIR PIPE HORIZONTAL TO SIDEWALL COMBUSTION-AIR PIPE VENT PIPE COMBUSTION-AIR PIPE 12″ MIN 12″ MIN VENT PIPE VERTICAL TO ROOF VERTICAL TO SIDEWALL NOTE: A 12 In. minimum offset pipe section is recommended with short (5 to 8 ft) vent systems. This recommendation is to reduce excessive condensate droplets from exiting the vent pipe. A96230 Fig.
PAGE 29
TABLE 7—MAXIMUM ALLOWABLE PIPE LENGTH (FT) ALTITUDE 0 to 2000 Altitude 2001 to 3000 Altitude 3001 to 4000 Altitude 4001 to 5000‡ Altitude 5001 to 6000‡ UNIT SIZE TERMINATION TYPE PIPE DIAMETER (IN.)* 042040 2 Pipe or 2-In. Concentric 042060 2 Pipe or 2-In. Concentric 042080 060080 2 Pipe or 2-In. Concentric 060100 2 Pipe or 2-In. Concentric 060120 2 Pipe or 3-In. Concentric 1-1/2 2 1-1/2 2 1-1/2 2 2 2-1/2 2-1/2 3 3† Unit Size Termination Type Pipe Diameter (In.
PAGE 30
TABLE 7—MAXIMUM ALLOWABLE PIPE LENGTH (FT) ALTITUDE 6001 to 7000‡ Altitude 7001 to 8000‡ Altitude 8001 to 9000‡ Altitude 9001 to 10000‡ UNIT SIZE TERMINATION TYPE PIPE DIAMETER (IN.)* 042040 2 Pipe or 2-In. Concentric 042060 2 Pipe or 2-In. Concentric 042080 060080 2 Pipe or 2-In. Concentric 060100 2 Pipe or 2-In. Concentric 060120 Continued 1-1/2 2 1-1/2 2 1-1/2 2 2 2-1/2 1 35 70 35 70 20 70 31 70 2 30 70 30 70 15 70 26 70 2 Pipe or 3-In.
PAGE 31
since it is less susceptible to damage, has reduced chances to take in contaminants, and has less visible vent vapors. (See Fig. 37 or 38.) Sidewall termination may require sealing or shielding of building surfaces with a corrosive resistance material due to corrosive combustion products of vent system. COMBUSTION – AIR INTAKE HOUSING 3/8" ID TUBE BURNER BOX EXTENDED EXPOSED SIDEWALL PIPES 3/16" DRILL TRAP Sidewall combustion-air and vent pipe terminations may be extended beyond area shown in Fig.
PAGE 32
ROOF 18″ MAXIMUM BRACKET COUPLING COMBUSTION AIR VERTICAL SEPARATION BETWEEN COMBUSTION AIR AND VENT 8 3/4″ FOR 3″ KIT 6 3/4″ FOR 2″ KIT VENT MAINTAIN 12 IN. MINIMUM CLEARANCE ABOVE HIGHEST ANTICIPATED SNOW LEVEL. MAXIMUM OF 24 IN. ABOVE ROOF. A87224 Fig. 37—Roof Termination (Preferred) OVERHANG OR ROOF 12″ MINIMUM 1″ MAXIMUM VENT COMBUSTION-AIR VENT COMBUSTION AIR MAINTAIN 12 IN. CLEARANCE ABOVE HIGHEST ANTICIPATED SNOW LEVEL OR GRADE, WHICHEVER IS GREATER. MAINTAIN 12 IN. (18 IN.
PAGE 33
A A96128 Fig. 42—Rooftop Termination (Dimension "A" is Touching or 2-In. Maximum Separation) 1″ MAXIMUM (TYP) VENT VENT A COMBUSTION AIR VENT COMBUSTION AIR A VENT A93057 A93056 Fig. 44—Concentric Vent and Combustion-Air Side Termination (Dimension "A" is Touching or 2-In. Maximum Separation) Fig. 43—Concentric Vent and Combustion-Air Roof Termination (Dimension "A" is Touching or 2-In.
PAGE 34
TABLE 8—MAXIMUM ALLOWABLE EXPOSED VENT PIPE LENGTH (FT) WITH INSULATION IN WINTER DESIGN TEMPERATURE AMBIENT* UNIT SIZE 042040 042060 042080 060080 060100 060120 WINTER DESIGN TEMPERATURE (°F) 20 0 -20 20 0 -20 20 0 -20 20 0 -20 20 0 -20 MAXIMUM PIPE DIAMETER (IN.) 2 2 2 2 2 2 2 2 2 2-1/2 2-1/2 2-1/2 3 3 3 INSULATION THICKNESS (IN.
PAGE 35
WARNING: PERSONAL INJURY AND PROPERTY DAMAGE HAZARD Failure to follow this warning could result in property damage and personal injury or death. Caution should be taken to prevent draining where slippery conditions may cause personal injuries. Excessive condensate draining may cause saturated soil conditions which could result in damage to plants. OPEN STAND PIPE FOR A/C OR HUMIDIFIER DRAIN CAUTION: UNIT MAY NOT OPERATE Failure to follow this caution may result in intermittent unit operation.
PAGE 36
5. Replace main furnace door and blower access door. NOTE: EAC-1 terminal is energized whenever blower operates. HUM terminal is only energized when blower is energized in heating. CAUTION: UNIT MAY NOT OPERATE Failure to follow this caution may result in intermittent unit operation or performance satisfaction. These furnaces are equipped with a manual reset limit switch in burner box.
PAGE 37
TABLE 9—FURNACE SETUP SWITCH DESCRIPTION SETUP SWITCH NO. SWITCH NAME NORMAL POSITION SW1-1 Status Code Recovery OFF SW1-2 Adaptive Heat Mode OFF SW1-3 Low Heat Rise Adjust OFF SW1-4 Comfort/Efficiency Adjustment ON SW1-5 CFM per ton adjust OFF SW1-6 Component Self-Test OFF SW1-7 Blower OFF delay ON or OFF SW1-8 Blower OFF delay ON or OFF 4. Replace main furnace door and blower access panel.
PAGE 38
NOTE: Low-heat-only switch, SW1-2, selects either the lowheat-only operation mode when ON, (see item 2. below) or adaptive heating mode when OFF, in response to a call for heat. (See Fig. 32.) When the W2 thermostat terminal is energized, it will always cause high-heat operation when the R to W circuit is closed, regardless of the setting of the low-heat only switch.
PAGE 39
5. 6. 7. 8. 9. 115 vac power to the furnace, or by interrupting 24 vac power at SEC1 or SEC2 to the furnace control CPU (not at W/W1, G, R, etc.). If flame is proved when flame should not be present, the furnace control CPU will lock out of Gas-Heating mode and operate the inducer motor IDM on high speed until flame is no longer proved. Inducer Speed Change-If the cycle starts in low-heat, the furnace control CPU reduces the inducer speed slightly after flame sense.
PAGE 40
energize the Y/Y2 terminal and switch the outdoor unit to high-cooling, as long as the thermostat continues to call for cooling. Subsequent selection is based on stored history of the thermostat cycle times. The cooling operation described in item 3. above applies to operation with a Thermidistat. The exceptions are listed below: a.
PAGE 41
When the thermostat ″calls for high-cooling″, the blower motor BLWM will operate at high-cooling airflow. When the thermostat is satisfied, the blower motor BLWM will operate an additional 90 seconds at high-cooling airflow before transitioning back to continuous-blower airflow. When the R to G circuit is opened, the blower motor BLWM will continue operating for an additional 5 seconds, if no other function requires blower motor BLWM operation.
PAGE 42
A00277 A00275 Fig. 56—Two-Stage Furnace with Single-Speed Heat Pump (Dual Fuel) Fig. 54—Two-Stage Furnace with Single-Speed Air Conditioner A00276 Fig. 55—Two-Stage Furnace with Two-Speed Air Conditioner A00278 Fig.
PAGE 43
A00281 A00279 Fig. 60—Two-Stage Thermostat With Two-Stage Furnace and Two-Speed Air Conditioner Fig. 58—Dual Fuel Thermostat with Two-Stage Furnace and Single-Speed Heat Pump See note 2 A02348 Fig. 61—Single-Stage Thermostat With Two-Stage Furnace and Two-Speed Air Conditioner A00280 Fig.
PAGE 44
Notes for Fig. 54-61: 1. Heat pump MUST have a high pressure switch for dual fuel applications. 2. Refer to outdoor equipment Installation Instructions for additional information and setup procedure. 3. Select the ″ZONE″ position on the two-speed heat pump control. 4. Outdoor Air Temperature Sensor must be attached in all dual fuel applications. 5. Dip switch No.1 on Thermidistat should be set in OFF position for air conditioner installations. This is factory default. 6. Dip switch No.
PAGE 45
TABLE 12 - ORIFICE SIZE* AND MANIFOLD PRESSURES FOR GAS INPUT RATE (TABULATED DATA BASED ON 20,000 BTUH HIGH-HEAT / 13,000 BTUH LOW-HEAT PER BURNER, DERATED 2%/1000 FT ABOVE SEA LEVEL) ALTITUDE AVG. GAS RANGE HEAT VALUE AT ALTITUDE U.S.A. Only U.S.A. and Canada U.S.A. and Canada (ft) 0 to 2000 U.S.A. Only 0.62 0.64 (Btu/cu ft) No. High/Low No. High/Low No. High/Low No. High/Low 900 43 3.5 / 1.5 43 3.6 / 1.5 43 3.8 / 1.6 42 3.2 / 1.3 925 44 3.8 / 1.6 43 3.5 / 1.5 43 3.
PAGE 46
TABLE 12 - ORIFICE SIZE* AND MANIFOLD PRESSURES FOR GAS INPUT RATE (TABULATED DATA BASED ON 20,000 BTUH HIGH-HEAT / 13,000 BTUH LOW-HEAT PER BURNER, DERATED 2%/1000 FT ABOVE SEA LEVEL) ALTITUDE AVG. GAS RANGE HEAT VALUE AT ALTITUDE (ft) U.S.A. Only U.S.A. Only 7001 to 8000 8001 to U.S.A. Only 9000 9001 to 10000 SPECIFIC GRAVITY OF NATURAL GAS 0.58 0.60 0.62 0.64 Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press (Btu/cu ft) No. High/Low No. High/Low No.
PAGE 47
e. Turn low-heat adjusting screw (3/32 hex Allen wrench) counterclockwise (out) to decrease input rate or clockwise (in) to increase input rate. a. Calculate high-altitude adjustment (if required). UNITED STATES At altitudes above 2000 ft, this furnace has been approved for a 2 percent derate for each 1000 ft above sea level. See Table 12 for derate multiplier factor and example. NOTE: DO NOT set low-heat manifold pressure less than 1.3-in. wc or more than 1.7-in. wc for natural gas.
PAGE 48
TABLE 13—GAS RATE CU FT/HR TABLE 12—ALTITUDE DERATE MULTIPLIER FOR U.S.A. ALTITUDE (FT) 0—2000 2001—3000 3001—4000 4001—5000 5001—6000 6001—7000 7001—8000 8001—9000 9001—10,000 % OF DERATE 0 4—6 6—8 8—10 10—12 12—14 14—16 16—18 18—20 DERATE MULTIPLIER FACTOR 1.00 0.95 0.93 0.91 0.89 0.87 0.85 0.83 0.
PAGE 49
b. Check derate for altitude if applicable. 1. The recommended method of checking this limit control is to gradually block off return air after furnace has been operating for a period of at least 5 minutes. c. Check all return and supply ducts for excessive restrictions causing static pressure greater than 0.5-in. wc. 2. As soon as limit control has shut off burners, a 33 status code will appear on furnace control. d.
PAGE 50
CHECKLIST—INSTALLATION LOAD CALCULATION Condensate Drain ____________ Heating Load (Btuh) ____________ Cooling Load (Btuh) ____________ Furnace Model Selection COMBUSTION AND VENT PIPING Termination Location ________ Roof or Sidewall ________ Termination Kit — 2 Pipe or Concentric ________ Combustion-Air Pipe Length ________ Combustion-Air Pipe Elbow Quantity ________ Vent Pipe Length ________ Vent Pipe Elbow Quantity ________ Pipe Diameter Determined from Sizing Table ________ Pipe Slo
PAGE 51
—51—
PAGE 52
SERVICE TRAINING Packaged Service Training programs are an excellent way to increase your knowledge of the equipment discussed in this manual, including: • Unit Familiarization • Maintenance • Installation Overview • Operating Sequence A large selection of product, theory, and skills programs is available, using popular video-based formats and materials. All include video and/or slides, plus companion book.