PLUS 95S -- MODEL 355CAV DIRECT--VENT 4--WAY MULTIPOISE CONDENSING GAS FURNACE WITH PERFECT SENSET PERFECT HUMIDITYT SERIES A Installation Instructions NOTE: Read the entire instruction manual before starting the installation. This furnace can be vented as a direct vent (2--pipe) or as an optional ventilated combustion air application. Furnaces installed in Canada must use Vent Systems that are certified to the Standard for Type BH Gas Venting Systems, ULC--S636.
Required Notice for Massachusetts Installations IMPORTANT The Commonwealth of Massachusetts requires compliance with regulation 248 CMR as follows: 5.08: Modifications to NFPA--54, Chapter 10 2) Revise 10.8.3 by adding the following additional requirements: (a.
SAFETY CONSIDERATIONS CAUTION ! FURNACE RELIABILITY HAZARD CUT HAZARD Improper installation or misapplication of furnace may require excessive servicing or cause premature component failure. Failure to follow this caution may result in personal injury. Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate protective clothing and gloves when handling parts.
26 15⁄16" 26 1⁄4" 24 26 1⁄4" A 22 5⁄16" 2-IN. COMBUSTIONAIR CONN 28 1⁄2" 26 15⁄16" AIRFLOW 1⁄ 2" 13 /16" 13 D CONDENSATE DRAIN TRAP LOCATION (DOWNFLOW & HORIZONTAL LEFT) DIA GAS CONN ⁄16" TYP /16" 19" OUTLET OUTLET CONDENSATE DRAIN TRAP LOCATION (DOWNFLOW & HORIZONTAL RIGHT) OR ALTERNATE 1⁄2-IN. DIA GAS CONN 7 1⁄2-IN. 22 5⁄16" 9 ⁄8-IN. DIA POWER CONN 355CAV ⁄2-IN.
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. These furnaces are shipped with the following materials to assist in proper furnace installation. These materials are shipped in the main blower compartment. debris from all HVAC system components after construction is completed.
CODES AND STANDARDS Installer Packet Includes: Installation, Start--- up, and Operating Instructions Follow all national and local codes and standards in addition to these instructions. The installation must comply with regulations of the serving gas supplier, local building, heating, plumbing, and other codes. In absence of local codes, the installation must comply with the national codes listed below and all authorities having jurisdiction in Canada.
drain and pressure tubes are connected as shown in Fig. 7. See appropriate application instructions for these procedures. The use of copper tubing for gas piping is not approved by the state of Massachusetts. Electrical Connections S US: National Electrical Code (NEC) ANSI/NFPA 70--2005. S CANADA: Canadian Electrical Code CSA C22.1. ! PROPERTY DAMAGE HAZARD Failure to follow this caution may result in property damage.
FURNACE DOOR BLOWER SHELF CONDENSATE TRAP CONDENSATE TRAP (INSIDE) FURNACE DOOR FURNACE SIDE 4 7 8 (124mm) FURNACE SIDE 4 5 3 4 (146mm) 5 3 4 (146mm) 4 FIELD DRAIN CONN ALTERNATE DRAIN TUBE LOCATION 11 2 (38mm) SIDE VIEW CONDENSATE TRAP DRAIN TUBE LOCATION 355CAV 26 1 4 (667mm) 26 1 4 (667mm) 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
PLUG COLLECTOR BOX DRAIN TUBE (BLUE & WHITE STRIPED) PLUG CAP COLLECTOR BOX DRAIN TUBE (BLUE & WHITE STRIPED) COLLECTOR BOX TUBE (PINK) CAP INDUCER HOUSING (MOLDED) DRAIN TUBE (BEHIND COLLECTOR BOX DRAIN TUBE) COLLECTOR BOX TUBE (PINK) COLLECTOR BOX DRAIN TUBE (BLUE) COLLECTOR BOX TUBE (GREEN ROUTES BEHIND INDUCER) COLLECTOR BOX TUBE (GREEN) CONDENSATE TRAP CONDENSATE TRAP FIELD-INSTALLED FACTORY-SUPPLIED DRAIN TUBE COUPLING (LEFT DRAIN OPTION) FIELD-INSTALLED FACTORY-SUPPLIED DRAIN TUBE FIELD-I
COLLECTOR BOX DRAIN TUBE (BLUE) PLUG COLLECTOR BOX TUBE (GREEN) CAP CAP COLLECTOR BOX DRAIN TUBE (BLUE) COLLECTOR BOX TUBE (GREEN) COLLECTOR BOX TUBE (PINK) COLLECTOR BOX TUBE (PINK) PLUG COLLECTOR BOX DRAIN TUBE (BLUE & WHITE STRIPED) COLLECTOR BOX DRAIN TUBE (BLUE & WHITE STRIPED) COLLECTOR BOX TUBE EXTENSION INDUCER HOUSING (MOLDED) DRAIN TUBE (VIOLET) 355CAV COLLECTOR BOX TUBE EXTENSION CONDENSATE TRAP CONDENSATE T RAP DRAIN TUBE COUPLING INDUCER HOUSING (MOLDED) DRAIN TUBE (VIOLET) COLL
b. Remove and discard UPPER (molded) inducer housing drain tube which was previously connected to condensate trap. PLUG CAP COLLECTOR BOX DRAIN TUBE (BLUE & WHITE STRIPED) 355CAV AUXILIARY “J” BOX CONDENSATE TRAP COLLECTOR BOX TUBE (GREEN) INDUCER HOUSING (MOLDED) DRAIN TUBE (VIOLET) COLLECTOR BOX TUBE EXTENSION COLLECTOR BOX EXTENSION DRAIN TUBE COLLECTOR BOX DRAIN TUBE (BLUE) COLLECTOR BOX TUBE (PINK) DRAIN TUBE COUPLING A07278 Fig. 11 -- Horizontal Left Tube Configuration c.
COMBUSTION – AIR INTAKE A 3-IN. MINIMUM CLEARANCE TO COMBUSTION-AIR INTAKE IS REQUIRED. VENT VENT COMBUSTION–AIR INTAKE 5 3 ⁄4 ″ 30″ MIN WORK AREA 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.
! Condensate Trap Location AUXILIARY “J” BOX INDUCER HOUSING (MOLDED) DRAIN TUBE (VIOLET) COLLECTOR BOX EXTENSION TUBE A07279 Failure to follow this caution may result in intermittent unit operation. HORIZONTAL RIGHT (SUPPLY-- AIR DISCHARGE) APPLICATIONS Fig. 14 -- Horizontal Right Tube Configuration The condensate trap must be removed from the factory--installed blower shelf location and relocated in selected application location as shown in Fig. 2 or 14.
355CAV Condensate Trap Tubing NOTE: See Fig. 14 or tube routing label on main furnace door to check for proper connections. 1. Collector Box DrainTube a. Remove factory--installed plug from LOWER collector box drain tube (blue and white striped label). b. Install removed clamp and plug into UPPER collector box drain tube (blue label) which was previously connected to condensate trap. c. Connect LOWER collector box drain tube (blue and white striped label) to condensate trap. Tube does not need to be cut.
! FRONT WARNING FIRE OR DEATH HAZARD Failure to follow this warning could result in property damage, personal injury, or death. Do not install furnace on its back. (See Fig. 16.) Safety control operation will be adversely affected. Never connect return--air ducts to back of furnace. B A C K FRONT A93043 Fig.
Hazardous Locations WARNING ! FIRE, EXPLOSION, INJURY OR DEATH HAZARD 355CAV Improper location or inadequate protection could result in fire or explosion. When furnace is installed in a residential garage, it must be installed so that burners and ignition sources are located a minimum of 18 in. (457.2mm) above floor. The furnace must be located or protected to avoid physical damage by vehicles.
FURNACE FACTORY SUPPLIED CASED COIL OR COIL BOX COMBUSTIBLE FLOORING A PLENUM OPENING B D SHEET METAL PLENUM FLOOR OPENING C 355CAV FLOOR OPENING A96283 A07586 Fig. 19 -- Floor and Plenum Opening Dimensions Fig.
355CAV 3 / 8-IN. ANGLE IRON OR EQUIVALENT ROD 5 3 / 4″ ALTERNATE SUPPORT LOCATION 4-IN. MIN 8-IN. MAX (B) (A) DRAIN (B) (A) (A) ROD LOCATION USING DIMPLE LOCATORS (SEE DIMENSIONAL DWG FOR LOCATIONS) (B) 3/8-IN. HEX NUT & WASHER (4) REQD PER ROD (A) PREFERRED ROD LOCATION (B) ALTERNATE ROD LOCATION (A) (B) 13/16-IN. MAX ALTERNATE SUPPORT LOCATION FROM BACK NOTES: 1. A 1 In. clearance minimum between top of furnace and combustible material. 2.
(APPROVED FACTORY SUPPLIED CASED COILS AND COIL BOX: CD5, CKR, CAPVP, CARVP, CAPMP, CARMP, CNPVP, CNRVP, AND KCAKC) Upflow Applications on Combustible or Noncombustible Flooring (KGASB subbase not required) Downflow Applications on Noncombustible Flooring (KGASB subbase not required) 17 ½ in.
humidifier, or other accessories. All accessories MUST be connected external to furnace main casing. Return Air Connections ! CUT HAZARD WARNING Failure to follow this caution may result in personal injury. Use care when cutting support rods in filters to protect against flying pieces and sharp rod ends. Wear safety glasses, gloves, and appropriate protective clothing. FIRE HAZARD Failure to follow this warning could result in personal injury, death or property damage.
FILTER RETAINER A93045 Fig. 24 -- Filter Installed for Side Inlet NOTE: Side return--air openings can ONLY be used in Upflow configurations. Install filter(s) as shown in Fig. 24. For bottom return--air applications, filter may need to be cut to fit some furnace widths. Install filter as shown in Fig. 25. 171⁄2-IN. WIDE CASINGS ONLY: INSTALL FIELD-SUPPLIED FILTER FILLER STRIP UNDER FILTER. 21-IN.
BOTTOM CLOSURE PANEL 355CAV FRONT FILLER PANEL A93047 Fig. 26 -- Removing Bottom Closure Panel GAS SUPPLY MANUAL SHUTOFF VALVE (REQUIRED) SEDIMENT TRAP UNION A93324 Fig. 27 -- Typical Gas Pipe Arrangement COMBUSTION-AIR PIPE GROMMET UNUSED 1-3/4 -IN. DIAMETER GAS CONN. HOLE COMBUSTION -AIR PIPE GAS LINE GAS LINE ENTRY HOLE FILLER PLUG VENT PIPE GAS LINE GROMMET VENT PIPE GROMMET NOTE: PIPE GROMMETS AND ENTRY HOLE FILLER PLUGS ARE INCLUDED IN FACTORY-SUPPLIED LOOSE PARTS BAG A05057 Fig.
Table 3 – Maximum Capacity of Pipe* INTERNAL DIAMETER (IN.) 1/2 3/4 1 1---1/4 1---1/2 0.622 0.824 1.049 1.380 1.610 ! LENGTH OF PIPE (FT/M) 10/ 3.0 20/ 6.1 30/ 9.1 40/ 12.2 50/ 15.2 175 360 680 1400 2100 120 250 465 950 1460 97 200 375 770 1180 82 170 320 660 990 73 151 285 580 900 * Cubic ft of gas per hr for gas pressure of 0.5 psig (14--- in. wc) or less, and a pressure drop of 0.5--- in. wc (based on a 0.60 specific gravity gas). Ref: Table 9--- 2 NFPA 54--- 2002.
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 Y THERMOSTAT TERMINALS FIELD-SUPPLIED DISCONNECT THREE-WIRE HEATING ONLY 208/230- OR 460-V THREE PHASE W/W1 115-V SINGLE PHASE W2 R 208/230-V SINGLE PHASE C GND NOTE 1 GND CONDENSING UNIT Y/Y2 24-V TERMINAL BLOCK FURNACE CONTROL CENTER GND G AUXILIARY 115-V FIELD-SUPPLIED J-BOX DISCONNECT SWITCH 355CAV GND NOTE 3 TWO WIRE NOTES: 1.
FACTORY INSTALLED LOCATION POWER ENTRY HOLE FILLER PLUG (FACTORYSUPPLIED LOOSE PARTS BAG) UNUSED 7/8-IN. DIAMETER POWER ENTRY HOLES A05113 A05113 Fig. 31 -- Factory Installed J--Box Location J--Box Relocation 1. Remove two screws holding auxiliary J--box. (See Fig. 32.) 2. Rotate J--box 180_ and attach box to left side, using holes provided. ALTERNATE FIELD LOCATION FACTORY INSTALLED LOCATION 24--v wiring Make field 24--v thermostat connections at 24--v terminal block on furnace control.
Removal of Existing Furnaces from Common Vent Systems When an existing Category I furnace is removed or replaced, the original venting system may no longer be sized to properly vent the remaining attached appliances. An improperly sized Category I venting system could cause the formation of condensate in the furnace and vent, leakage of condensate and combustion products, spillage of combustion products into the living space, etc.
Table 5 – Approved Combustion--Air and Vent Pipe, Fitting and Cement Materials ASTM MATERIAL PIPE SOLVENT CEMENT FITTINGS (MARKED ON MATERIAL) D1527 D1785 D2235 ABS PVC For ABS Pipe Pipe — — — — D2241 D2466 D2468 D2564 PVC PVC ABS For PVC Pipe — — — — Fittings Fittings — D2661 D2665 F438 F441 F442 F493 ABS PVC CPVC CPVC CPVC For CPVC Pipe Pipe — Pipe Pipe — Fittings Fittings Fittings — — — F628 ABS Pipe — — F656 For PVC — — Primer F891 PVC Pipe — — DESCRIPTION AND PRIMERS In
MODEL PLUG CONNECTOR USER INTERFACE OR ADVANCED PRODUCT MONITOR CONNECTOR CONTINUOUS FAN (CF) AIRFLOW SETUP SWITCHES OAT CONNECTOR SW4 SETUP SWITCHES SW1 SETUP SWITCHES AND BLOWER OFFDELAY 355CAV AIR CONDITIONING (A/C) AIRFLOW SETUP SWITCHES HUMIDIFIER TERMINAL (24-VAC 0.5 AMP MAX.
355CAV 12 inches (30 cm) for applieances >10,000 Btuh(3 kW) and < 100,000 Btuh(30kW), 36 inches (91cm) for appliances > 100,000 Btuh(30kW) A06675 Fig.
355CAV A05013 Fig.
Roof Te rmination (Preferred) At least 36 in. Concentric Vent and Combustion Air Roof Termination (preferred) A A At least 36 in. 18 in. maximum Maintain 12 in. min. clearance above highest anticipated snow level Maximum of 24 in. above roof Maintain 12 in. min. clearance above highest anticipated snow level, maximum of 24 in. above roof 1 in. maximum (typ) from wall to inlet Abandoned masonry used as raceway (per code) 12 in. minimum from overhang or roof Note: "A" denotes 0 to < 2 in.
NOTE: Select 1 vent pipe connection and NOTE: Select 1 vent pipe connection and 1 combustion-air pipe connection. 1 combustion-air pipe connection. COMBUSTIONAIR FURNACE AIR FLOW COMBUSTIONAIR VENT VENT VENT VENT NOT IN HORIZONTAL SECTION COMBUSTIONAIR PIPE DIAMETER TRANSITION IN VERTICAL SECTION UPFLOW AIR FLOW COMBUSTIONAIR DOWNFLOW 355CAV A93034 Fig.
COMBUSTION AIR INTAKE HOUSING 3/8" ID TUBE ! BURNER BOX CAUTION UNIT CORROSION HAZARD Failure to follow this caution may result in reduced furnace component life. COMBUSTION AIR PIPE 4″ MIN TRAP TO OPEN DRAIN A93035 Fig. 40 -- Intake Housing Plug Fitting Drain 8. Install casing hole filler cap (factory--supplied in loose parts bag) in unused combustion air pipe casing hole.
Crawlspace terminations require the open end of the combustion air intake pipe to point downward. Maintain 3 inches (76.2mm) of clearance below the floor joist insulation and 12 inches (304.8mm) above the grade. Screen the elbow with a wire mesh screen no smaller than 3/8--in. (9.5mm) square. (See Fig. 42 and 43.) ! VENT PIPE General Furnace vent connection must be attached as shown in Fig. 39.
5CAV (304.8mm) minimum A06672 Fig. 41 -- Attic Termination (76.2 mm) minimum (304.8 mm) minimum A06673 Fig.
3” (76.2mm) minimum 355CAV (304.8mm) minimum A06674 Fig.
12″ MIN 12″ MIN VENT PIPE VENT PIPE COMBUSTION-AIR PIPE COMBUSTION-AIR PIPE HORIZONTAL TO SIDEWALL 355CAV HORIZONTAL TO ROOF COMBUSTION-AIR PIPE VENT PIPE COMBUSTION-AIR PIPE 12″ MIN (304.8mm) 12″ MIN (304.8mm) VENT PIPE VERTICAL TO ROOF VERTICAL TO SIDEWALL NOTE: A 12-in. (304.8mm) minimum offset pipe section is recommended with short (5 to 8 ft) vent systems. This recommendation is to reduce excessive condensate droplets A96230 Fig. 44 -- Short Vent (5 to 8 Ft or 1.5M -- 2.
355CAV Vent Termination Kit (Direct Vent/2--Pipe System Only) NOTE: Always refer to the instructions in termination kit for the latest version. Combustion air and vent pipes MUST terminate outside structure. A factory accessory termination kit must be installed as shown in Table 8. There are four options of vent/combustion air termination kits available as shown in Table 8. NOTE: Combustion air pipe must have the same diameter as vent pipe.
042060 042080 060080 060100 060120 1 70 / 21.3 53 / 16.2 38 / 11.6 70 / 21.3 63 / 19.2 45 / 13.7 70 / 21.3 68 / 20.7 49 / 14.9 70 / 21.3 70 /21.3 59 / 18.0 * Pipe length (ft/m) specified for maximum pipe lengths located in unconditioned spaces. Pipes located in unconditioned space cannot exceed total allowable pipe length as specified in Table ?. †Insulation thickness based on R value of 3.5 per in.
Table 7 – Maximum Allowable Pipe Length (Ft / M) ALTITUDE UNIT SIZE (BTUH) 60,000 80,000 0 to 2000 100,000 120,000 355CAV ALTITUDE UNIT SIZE (BTUH) 60,000 80,000 2001 to 3000 100,000 120,000 ALTITUDE UNIT SIZE (BTUH) 60,000 80,000 3001 to 4000 100,000 120,000 ALTITUDE UNIT SIZE (BTUH) 60,000 80,000 4001 to 5000‡ 100,000 120,000 ALTITUDE UNIT SIZE (BTUH) 60,000 80,000 5001 to 6000‡ 100,000 120,000 Direct Vent (2--Pipe Only) Termination Pipe Dia Type (IN.)* 2 Pipe or 2--- In.
Table 9 — Maximum Allowable Pipe Length (Ft / M) (Continued) UNIT SIZE (BTUH) 60,000 6001 to 7000‡ 80,000 100,000 120,000 ALTITUDE UNIT SIZE (BTUH) 60,000 7001 to 8000‡ 80,000 100,000 120,000 ALTITUDE UNIT SIZE (BTUH) 60,000 8001 to 9000‡ 80,000 100,000 120,000 ALTITUDE UNIT SIZE (BTUH) 60,000 9001 to 10000‡ 80,000 100,000 120,000 NUMBER OF 90_ ELBOWS Direct Vent (2--Pipe Only) Termination Type 2 Pipe or 2--- In. Concentric 2 Pipe or 2--- In. Concentric 2 Pipe or 2--- In.
Table 8 – Vent Termination Kit for Direct Vent / 2--Pipe System DIAMETER OF COMBUSTION AIR DIRECT VENT (2 PIPE) TERMINATION TERMINATION SYSTEM AND VENT PIPES (IN INCHES) KIT 2in. Concentric Vent Kit Single Penetration of Wall or Roof 1, 1--1/2, 2, or 2--1/2 3in. Concentric Vent Kit Single Penetration of Wall or Roof 2--1/2, 3 or 4 2in. Termination Bracket Kit 2Pipe Termination System 1, 1--1/2 or 2 3in.
START--UP, ADJUSTMENT AND SAFETY CHECK continuous fan airflow or low--cooling airflow to be adjusted. To set desired continuous fan airflow or low--cooling airflow: 1. Remove main furnace door and blower access panel. 2. Locate CF setup switches on furnace control. (See Fig. 33.) 3. Determine desired continuous fan airflow or low--cooling airflow. 4. Use Fig. 47 or wiring schematic to determine proper setup position of CF switches. (See Fig. 48 and Fig. 49.) 5.
2. Locate setup switch SW4 on furnace control. (See Fig. 33.) 3. See Table 5 for setup switch description. (See Fig. 40 and Fig. 49.) 4. Replace main furnace door and blower access panel. Prime Condensate Trap with Water ! CAUTION UNIT OPERATION HAZARD 355CAV Failure to follow this caution may result in intermittent unit operation or performance satisfaction. Condensate trap must be PRIMED or proper draining may not occur.
355CAV A06677 Fig.
355CAV A99118 A01050 Fig. 50 -- Inducer Housing Drain Tube Fig. 51 -- Filling Condensate Trap Table 9 – Furnace Setup Switch Description SETUP SWITCH NO.
! CAUTION FIRE AND EXPLOSION HAZARD Failure to follow this caution could result in a fire, explosion, personal injury, or death. Never purge a gas line into a combustion chamber. Never test for gas leaks with an open flame. Use a commercially available soap solution made specifically for the detection of leaks to check all connections. Step 3 — Sequence of Operation ! CAUTION UNIT OPERATION HAZARD Failure to follow this caution may result in intermittent unit operation.
355CAV and operate the inducer motor IDM at full speed until flame is no longer proved. 5. Inducer Speed Change — If the cycle starts in mediumheat, the furnace control CPU reduces the inducer speed slightly after flame sense. If cycle starts in high--heat, the furnace control CPU increases the inducer speed after flame sense. The reduction in speed in medium--heat is to optimize combustion for maximum efficiency. 6.
The wall thermostat “calls for cooling”, closing the R to G and-Y circuits. The R to Y1 circuit starts the outdoor unit on low--cooling speed, and the R to G--and--Y1 circuits starts the furnace blower motor BLWM at low--cooling airflow which is the true on--board CF selection as shown in Fig. 47. If the furnace control CPU switches from low--cooling to high cooling, the furnace control CPU will energize the air conditioning relay ACR.
355CAV 2. High cooling – When the R to G--and Y/Y2 circuit is closed and there is a demand for dehumidification, the furnace blower motor BLWM will drop the blower airflow to 86% of high--cooling airflow. High--cooling airflow is based on the A/C selection shown in Fig. 47. 3. Cooling off--delay – When the “call for cooling” is satisfied and there is a demand for dehumidification, the cooling blower--off delay is decreased from 90 seconds to 5 seconds.
355CAV A06678 A06680 Fig. 52 -- Step--Modulating Furnace with Single--Speed Air Conditioning Fig. 54 -- Step Modulating Furnace with Single--Speed Heat Pump (Dual Fuel) A06679 A06681 Fig. 53 -- Step Modulating Furnace with Two--Speed Air Conditioner Fig.
355CAV A06682 A06684 Fig. 56 -- Step Modulating Furnace with Single--Speed Heat Pump Fig. 58 -- Two--Stage Thermostat with Step Modulating Furnace and Two--Speed Air Conditioner A06683 A06685 Fig. 57 -- Dual Fuel thermostat with Step--Modulating Furnace and Two--Speed Heat Pump Fig.
NOTE: For Canadian altitudes of 2000 to 4500 ft, use U.S.A. altitudes of 2001 to 3000 ft in Table 10. e. Find closest natural gas heat value and specific gravity in Table 10. f. Follow heat value and specific gravity lines to point of intersection to find orifice size and low--, medium--, and high--heat manifold pressure settings for proper operation. EXAMPLE: (0 -- 2000 ft altitude) Heating value = 1050 Btu/cu ft Specific gravity = 0.62 Therefore: Orifice No. 45 Manifold pressure: 3.8--in.
NOTE: DO NOT set medium--heat manifold pressure less than 1.3-- in. wc or more than 1.7--in. wc for natural gas. ! CAUTION UNIT DAMAGE HAZARD Failure to follow this caution may result in reduced furnace life. 355CAV DO NOT bottom out gas valve regulator adjusting screws. This can result in unregulated manifold pressure and result in excess overfire and heat exchanger failures.
355CAV Table 10 – Orifice Size* and Manifold Pressures for Gas Input Rate (Tabulated Data Based on 20,000 BTUH High Heat / 13,000 Btuh Med--Heat / 8,000 Btuh Low--Heat per Burner, Derated 2% / 1000 Ft.
355CAV Orifice Size* and Manifold Pressures for Gas Input Rate (Tabulated Data Based on 20,000 BTUH High Heat / 13,000 Btuh Med--Heat / 8,000 Btuh Low--Heat per Burner, Derated 2% / 1000 Ft.
CAUTION UNIT DAMAGE HAZARD Failure to follow this caution may result in component damage. DO NOT redrill orifices. Improper drilling (burrs, out--of--round holes, etc.) can cause excessive burner noise and misdirection of burner flames. (See Fig. 61.) h. Jumper R to W/W1. i. Let furnace run for 3 minutes in medium--heat operation. j. Measure time (in sec) for gas meter to complete 1 revolution. Note reading. k. Refer to Table 12 for cubic ft of gas per hr. l.
Table 12 – Gas Rate cu Ft/Hr 355CAV SECONDS FOR 1 REVOLUTION 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 SIZE OF TEST DIAL 1 2 5 cu ft cu ft cu ft 360 720 1800 327 655 1636 300 600 1500 277 555 1385 257 514 1286 240 480 1200 225 450 1125 212 424 1059 200 400 1000 189 379 947 180 360 900 171 343 857 164 327 818 157 313 783 150 300 750 144 288 720 138 277 692 133 267 667 129 257 643 124 248 621 120 240 600 116 232 581 113 225 563 1
NOTE: When using an electronic thermostat, set cycle rate for 3 cycles per hr. 3. Return setup switch SW1--2 to OFF position and replace thermostat on subbase. Check Safety Controls This section covers the safety controls that must be checked before the installation is complete. The flame sensor, gas valve, and pressure switches were all checked in the Start--up procedure section as part of normal operation.
CHECKLIST — INSTALLATION LOAD CALCULATION ________________ Heating Load (Btuh) ________________ Cooling Load (Btuh) ________________ Condensate Drain Furnace Model Selection COMBUSTION AND VENT PIPING Termination Location ________________ Vent ________________ Roof 355CAV ________________ ________________ ________________ Unit Level or Pitched Forward ________________ Internal Tubing Connections Free of Kinks and Traps ________________ External Drain Connection Leak Tight and Sloped _____
