Bryant 376CAV Installation Instruction

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Installation, Start-Up, and

376CAV

Operating Instructions

DOWNFLOW/HORIZONTAL GAS-FIRED INDUCED-COMBUSTION FURNACES

NOTE: Read the entire instruction manual before starting the installation.

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TABLE OF CONTENTS

SAFETY CONSIDERATIONS.....................................................1

INTRODUCTION..........................................................................1

CODES AND STANDARDS........................................................3

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS........3

LOCATION....................................................................................4

General......................................................................................4

Location Relative to Cooling Equipment ................................4

Hazardous Locations.................................................................4

Unconfined Space.....................................................................4

Confined Space.........................................................................5

AIR DUCTS...................................................................................5

General Requirements...............................................................5

Ductwork Acoustical Treatment...............................................5

Supply Air Connections............................................................5

Return Air Connections............................................................6

Downflow Installation ..............................................................6

Horizontal Attic Installation.....................................................6

Horizontal Crawlspace Installation ..........................................7

Filter Arrangement....................................................................8

Gas Piping.................................................................................9

Electrical Connections............................................................11

Venting....................................................................................11

START-UP PROCEDURES, ADJUSTEMENT, AND SAFETY

CHECK.........................................................................................11

General....................................................................................11

Sequence of Operation............................................................12

Start-Up Procedures................................................................15

Adjustments.............................................................................15

Check Safety Controls............................................................19

Checklist..................................................................................20

SAFETY CONSIDERATIONS

Installing and servicing heating equipment can be hazardous due to gas and electrical components. Only trained and qualified personnel should install, repair, or service heating equipment.

Untrained personnel can perform basic maintenance functions such as cleaning and replacing air filters. All other operations must be performed by trained service personnel. When working on heating equipment, observe precautions in literature, on tags, and on labels attached to or shipped with unit and other safety precautions that may apply.

In the United States, follow all safety codes including the National Fuel Gas Code (NFGC) NFPA 54-1999/ANSI Z223.1-1999 and the Installation Standards, Warm Air Heating and Air Conditioning Systems (NFPA 90B) ANSI/NFPA 90B.

In Canada, refer to the current edition of the CAN/CGA-B149.1and .2-M99 National Standard of Canada, Natural Gas and Propane Installation Codes (NSCNGPIC).

Series H&J

Cancels: II 376C-50–3 II 376C–50–5

10–00

EFFICIENCY RATING CERTIFIED

REGISTERED QUALITY SYSTEM

Wear safety glasses and work gloves. Have a fire extinguisher available during start-up and adjustment procedures and service calls. Recognize safety information. This is the safety-alert symbol When you see this symbol on the furnace and in instructions or manuals, be alert to the potential for personal injury. Understand these signal words; DANGER, WARNING, and CAUTION and NOTE. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies a hazard which could result in personal injury or death. CAUTION is used to identify unsafe practices which would result in minor personal injury or product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation These instructions cover minimum requirements and conform to existing national standards and safety codes. In some instances, these instructions exceed certain local codes and ordinances, especially those that may not have kept pace with changing residential construction practices. We require these instructions as a minimum for a safe installation.

INTRODUCTION

The Model 376CAV, Series H and J Furnace is available in sizes 46,000 through 135,000 Btuh input capacities. The design of the downflow/horizontal gas-fired furnace is (A.G.A. & C.S.A.) certified for natural and propane gases and for installation on noncombustible flooring. The furnace is factoryshipped for use with natural gas. A factory accessory gas conversion kit, as listed on the furnace rating plate is required to convert furnace for use with propane gas. These furnaces SHALL NOT be installed directly on carpeting, tile, or any combustible material other than wood flooring. In downflow installations, a factory accessory floor base, as listed on the furnace rating plate, MUST be used when installed on combustible materials and wood flooring. A factory base is not required when this furnace is installed on manufacturer’s Coil Assembly Part No. CD5 or CK5, or when Coil Box Part No. KCAKC is used. This furnace is for installation in alcoves, attics, crawlspaces, basements, closets, or utility rooms. The design of this furnace line is not (A.G.A./C.S.A.) certified for installation in mobile homes, recreation vehicles, or outdoors.

CERTIFIED

—1—

⁄2†

20†

⁄16†

⁄8†

INLET

⁄8† DIA

ACCESSORY

⁄4† DIA HOLE

GAS ENTRY

⁄16†

OUTLET

19†

NOTE:

ADDITIONAL LOCA TED IN THE TOP PLA TE

⁄8† DIA K.O.’s ARE

AND BOTTOM PLATE

VENT CONNECTION

⁄16†

⁄8†

⁄4†

⁄16†

⁄8†

⁄4†

⁄16†

AIRFLOW

⁄16†

⁄4†

DIMPLES TO DRILL HOLES FOR HANGER BOLTS (4 PLACES) IN HORIZONTAL POSITION

⁄2† DIA

2†

THERMOSTAT WIRE ENTRY

⁄8† DIA

ACCESSORY

⁄8† DIA HOLE

POWER ENTRY

⁄2† DIA

R.H. GAS ENTRY

⁄8† DIA

ACCESSORY

⁄16†

⁄8†

† TYP

⁄8† TYP

NOTE:

Minimum return-air openings at furnace, based on metal duct. If flex duct is used, see flex duct manufacturer's recommendations for equivalent diameters. a. For 800 CFM–16-in. round or 14 b. For 1200 CFM–20-in. round or 14 c. For 1600 CFM–22-in. round or 14 d. For airflow requirements above 1800 CFM, must use entire return air opening.

⁄2 x 12-in. rectangle.

⁄2 x 191⁄2-in. rectangle.

⁄2 x 231⁄4-in. rectangle.

TABLE 1—DIMENSIONS (IN.)

UNIT SIZE A D E VENT CONN SHIP. WT (LB)

024050 14-3/16 12-9/16 12-11/16 4 123 036050 14-3/16 12-9/16 12-11/16 4 128 024070 14-3/16 12-9/16 12-11/16 4 130 036070 14-3/16 12-9/16 12-11/16 4 139 036096 17-1/2 15-7/8 16 4 151 048096 17-1/2 15-7/8 16 4 153 048115 17-1/2 15-7/8 16 4 161 060115 21 19-3/8 19-1/2 4 177 066115 21 19-3/8 19-1/2 4 176 060135 24-1/2 22-7/8 23 5 193

Fig. 1—Dimensional Drawing

These instructions cover minimum requirements for a safe installation and conform to existing national standards and safety codes. In some instances, these instructions exceed certain local codes and ordinances, especially those that may not have kept pace with changing residential construction practices. We require these instructions as a minimum for a safe installation.

A99288

CAUTION: Application of this furnace should be indoors with special attention given to vent sizing and material, gas input rate, air temperature rise, and unit sizing. Improper installation or misapplication of the furnace can require excessive servicing or cause premature component failure.

NOTE: These furnaces are designed for a minimum continuous return-air temperature of 60°F or intermittent operation down to 55°F such as when used with a night setback thermostat. Return-air temperature must not exceed a maximum of 85°F. Failure to follow these return-air temperature limits may affect reliability of heat exchangers, motors, and controls.

A93042

—2—

MINIMUM INCHES CLEARANCE TO COMBUSTIBLE CONSTRUCTION

This fo rced air furnace is equipped for use with natural

gas at altitudes 0-10,000 ft (0-3,050m).

An accessory kit, supplied by the manufacturer,shall be used to convert to propane gas use or may be require d for somenatura l gas applications.

This furnace is for indoor installatio n in a building constructed on site.

This furnace may be installed on combustible flooring in alcove or closet at minimum clearance from combustible material.

This furnace may be used with a Type B-1 Vent and may be vented in com m on with other gas-fired appliances.

For installation on non-combustible floors only.

†

For installation on combustible flooring onlywhen installedon specia l base, Part No. KGA SB02 01ALL, Coil Assembly, Part No.CD5 or CK5, or Coil Casing, Part No. KCAKC.

For furnaces wider than 14.25 inches (362mm) may

be 0 inches.

18 inches fro nt clearance re quired for alcove.

Indicates supply or return sides whenfurnaceisin

the horizonta l position. Line contact only permissible betweenlines formed by intersectionsof the Top and two Sides of thefurnace jacke t, and building joists, studs or fram ing.

For single wall vent typ e 6 inches.

ForTypeB-1venttype3inches.

††

Clearance to Back 0 inches in downflow and horizontal (attic/alcove & craw lspace) positionsand 3 inches in horizontal closet positions.

Fig. 2—Clearances to Combustibles

ThisfurnaceisapprovedforDOWNFLOWandHORIZONTAL installatio ns .

Clearance arrow s do not change with furnace orientatio n.

†

1" #

Clearance in inch es

TOP / PLENUM

†

BOTTOM

30"

MIN

Vent Clearance to combustibles:

For Sin gle Wall vents 6 inches. For Type B-1 vent type1 inch .

322286-101REV. F (LIT)

A99262

WARNING: Improper installation, adjustment, alteration, service, maintenance, or use can cause carbon monoxide poisoning, explosion, fire, electrical shock, or other conditions which may cause personal injury or property damage. Consult a qualified installer, service agency, local gas supplier, or your distributor or branch for information or assistance. The qualified installer or agency must use only factory-authorized and listed kits or accessories when modifying this product. Failure to follow this warning could result in electrical shock, fire, personal injury, or death.

For accessory installation details, refer to the applicable installation literature.

NOTE: Remove all shipping brackets and materials before operating the furnace.

CODES AND STANDARDS

Before installing the furnace in the United States, refer to the current edition of the NFGC and the NFPA 90B. For further information the NFGC and NFPA 90B are available from National Fire Protection Association Inc., Batterymarch Park, Quincy, MA 02269; or for only the NFGC contact the American Gas Association, 400 N. Capitol St., N.W., Washington DC 20001.

Before installing the furnace in Canada, refer to the current edition of the NSCNGPIC. For a copy of the NSCNGPIC, contact Standard Sales, CSA International, 178 Rexdale Boulevard, Etobicoke (Toronto), Ontario, M9W 1R3, Canada.

Installation must comply with regulations of serving gas supplier and local building, heating, plumbing or other codes in effect in the area in which installation is made. In absence of local building codes, installation must comply with NFGC in the United States and the NSCNGPIC and all authorities having jurisdiction in Canada.

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS

CAUTION: Electrostatic discharge can affect electronic

components. Take precautions during furnace installation and servicing to protect the furnace electronic control. Precautions will prevent electrostatic discharges from personnel and hand tools which are held during the procedure. These precautions will help to avoid exposing the control to electrostatic discharge by putting the furnace, the control, and the person at the same electrostatic potential.

1. Disconnect all power to the furnace. DO NOT TOUCH

THE CONTROL OR ANY WIRE CONNECTED TO THE CONTROL PRIOR TO DISCHARGING YOUR BODY’S ELECTROSTATIC CHARGE TO GROUND.

2. Firmly touch a clean, unpainted, metal surface of the furnace chassis which is close to the control. Tools held in a person’s hand during grounding will be satisfactorily discharged.

3. After touching the chassis you may proceed to service the control or connecting wires as long as you do nothing that

—3—

recharges your body with static electricity (for example; DO NOT move or shuffle your feet, DO NOT touch ungrounded objects, etc.).

4. If you touch ungrounded objects (and recharge your body with static electricity), firmly touch furnace again before touching control or wires.

5. Use this procedure for installed and uninstalled (ungrounded) furnaces.

6. Before removing a new control from its container, discharge your body’s electrostatic charge to ground to protect the control from damage. If the control is to be installed in a furnace, follow items 1 through 5 before bringing the control or yourself into contact with the furnace. Put all used AND new controls into containers before touching ungrounded objects.

7. An ESD service kit (available from commercial sources) may also be used to prevent ESD damage.

LOCATION

I. GENERAL

CAUTION: Do not install furnace in a corrosive or

contaminated atmosphere. Make sure all combustion and circulating air requirements are met, in addition to all local codes and ordinances. Do not use this furnace during construction when adhesives, sealers, and/or new carpets are being installed. If the furnace is required during construction, use clean outside air for combustion and ventilation. Compounds of chlorine and fluorine when burned with combustion air form acids which cause corrosion of the heat exchangers and metal vent system. Some of these compounds are found in paneling and dry wall adhesives, paints, thinners, masonry cleaning materials, and many other solvents commonly used in the construction process. Excessive exposure to contaminated combustion air will result in safety and performance related problems.

III. HAZARDOUS LOCATIONS

18-IN. MINIMUM

TO BURNERS

A93044

WARNING: 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. above floor. The furnace must be located or protected to avoid physical damage by vehicles. When furnace is installed in a public garage, airplane hangar, or other building having a hazardous atmosphere, unit must be installed in accordance with requirements of National Fire Protection Association, Inc.

Air For Combustion And Ventilation

Provisions for adequate combustion and ventilation air must be provided in accordance with Section 5.3 of the NFGC, Air for Combustion and Ventilation, or applicable provisions of the local building codes.

Canadian installations must be installed in accordance with NSCNGPIC and all authorities having jurisdiction.

WARNING: DO NOT install the furnace on its back or sides. Safety control operation will be adversely affected. A failure to follow this warning can cause a fire, personal injury, or death.

This furnace must be installed so the electrical components are protected from water.

Locate furnace as close to the chimney/vent and as near the center of the air distribution system as possible. The furnace should be installed as level as possible.

Provide ample space for servicing and cleaning. Always comply with the minimum fire protection clearances shown on the unit rating plate. This furnace shall not be installed directly on carpeting, tile, or any combustible material other than wood flooring. The furnace may be installed on combustible flooring when installed with the accessory downflow subbase, which is available from your distributor or branch when required.

II. LOCATION RELATIVE TO COOLING EQUIPMENT

The cooling coil must be installed parallel with or on the downstream side of the unit to avoid condensation in the heat exchangers. When installed parallel with a furnace, dampers or other means used to control the flow of air must prevent chilled air from entering the unit. If the dampers are manually operated, they must be equipped with means to prevent operation of either unit unless the damper is in the full-heat or full-cool position.

CAUTION: Air for combustion must not be contaminated by halogen compounds, which include fluoride, chloride, bromide, and iodide. These elements are found in aerosol sprays, detergents, bleaches, cleaning solvents, salts, air fresheners, and other household products.

CAUTION: The operation of exhaust fans, kitchen ventilation fans, clothes dryers, or fireplaces could create a NEGATIVE PRESSURE CONDITION at the furnace. Make-up air MUST be provided for the ventilation devices, in addition to that required by the furnace.

All fuel-burning equipment must be supplied with air for combustion of the fuel. Sufficient air MUST be provided to ensure there will not be a negative pressure in the equipment room or space. In addition, a positive seal MUST be made between the furnace cabinet and the return-air duct to avoid pulling air from the burner area and blocked vent safeguard opening.

The requirements for combustion and ventilation air depend upon whether the furnace is located in an unconfined or confined space.

IV. UNCONFINED SPACE

An unconfined space has volume of at least 50 cu ft for each 1000 Btuh of total input for all appliances (such as furnaces, clothes dryers, water heaters, etc.) in the space.

—4—

For Example:

376CAV FURNACE

INPUT BTUH

46,000 307 69,000 460

92,000 613 115,000 767 135,000 920

MINIMUM SQ FT WITH

7–1/2 FT CEILING

If the unconfined space is of unusually tight construction, air for combustion and ventilation MUST come from either the outdoors or spaces freely communicating with the outdoors. Combustion and ventilation openings must be sized the same as for a confined space as defined below. Return air must not be taken from the room unless an equal or greater amount of air is supplied to the room.

V. CONFINED SPACE

A confined space is defined as a space whose volume is less than 50 cu ft per 1000 Btuh of total input ratings of all appliances installed in that space. A confined space MUST have provisions for supplying air for combustion, ventilation, and dilution of flue gases using 1 of the following methods. (See Figs. 3, 4, and Table

2.) NOTE: In determining free area of an opening, the blocking

effect of louvers, grilles, and screens must be considered. If free area of louver or grille design is unknown, assume that wood louvers have a 20 percent free area and metal louvers or grilles have a 60 percent free area. Screens, when used, must not be smaller than 1/4-in. mesh. Louvers and grilles must be constructed so they cannot be closed.

The size of the openings depends upon whether air comes from outside of the structure or an unconfined space inside the structure.

1. All air from inside the structure requires 2 openings (for structures not usually tight):

a. Each opening MUST have at least 1 sq in. of free area

per 1000 Btuh of total input for all equipment within the confined space, but not less than 100 sq in. per opening. (See Fig. 3 and Table 2.) The minimum dimension of air openings shall not be less than 3 in.

b. If building is constructed unusually tight, a permanent

opening directly communicating with the outdoors shall be provided. See item 2 below.

c. If furnace is installed on a raised platform to provide a

return-air plenum, and return air is taken directly from hallway or space adjacent to furnace, all air for combustion must come from outdoors.

2. Air from outside the structure requires 1 of the following methods:

a. If combustion air is taken from outdoors through 2

vertical ducts, the openings and ducts MUST have at least 1 sq in. of free area per 4000 Btuh of total input for all equipment within the confined space. (See Figs. 3, 4, and Table 2.)

b. If combustion air is taken from outdoors through 2

horizontal ducts, the openings and ducts MUST have at least 1 sq in. of free area per 2000 Btuh of total input for all equipment within the confined space. (See Fig. 4 and Table 2.)

c. If combustion air is taken from outdoors through a single

opening or duct (horizontal or vertical) commencing within 12 in. of the top of the confined space, opening and duct MUST have at least 1 sq in. of free area per

3000 Btuh of the total input for all equipment within the confined space and not less than the sum of the areas of all vent connectors in the confined space. (See Fig. 4 and Table 2.) Equipment clearances to the structure shall be at least 1 in. from the sides and back and 6 in. from the front of the appliances.

When ducts are used, they must be of the same cross-sectional area as the free area of the openings to which they connect. The minimum dimension of ducts must not be less than 3 in. (See Fig.

4.)

AIR DUCTS

This section covers installation of the 376CAV Series H and J furnace.

I. GENERAL REQUIREMENTS

The duct system should be designed and sized according to accepted national standards such as those published by: Air Conditioning Contractors Association (ACCA), Sheet Metal and Air Conditioning Contractors National Association (SMACNA) or American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE). Or consult factory The Air Systems Design Guidelinesreference tables available from your local distributor. The duct system should be sized to handle the required system design airflow CFM at the design external static pressure.

When a furnace is installed so that the supply ducts carry air to areas outside the space containing the furnace, the return air must also be handled by a duct(s) sealed to the furnace casing and terminating outside the space containing the furnace.

Secure ductwork with proper fasteners for type of ductwork used. Seal supply- and return-duct connections to furnace with code approved tape or duct sealer.

Flexible connections should be used between ductwork and furnace to prevent transmission of vibration. Ductwork passing through unconditioned space should be insulated to enhance system performance. When air conditioning is used, a vapor barrier is recommended.

Maintain a 1-in. clearance from combustible materials to supply air ductwork for a distance of 36 in. horizontally from the furnace. See NFPA 90B or local code for further requirements.

II. DUCTWORK ACOUSTICAL TREATMENT

Metal duct systems that do not have a 90 degree elbow and 10 ft of main duct to the first branch take-off may require internal acoustical lining. As an alternative, fibrous ductwork may be used if constructed and installed in accordance with the latest edition of SMACNA construction standard on fibrous glass ducts. Both acoustical lining and fibrous ductwork shall comply with NFPA 90B as tested by UL Standard 181 for Class 1 Rigid air ducts.

III. SUPPLY AIR CONNECTIONS A. Downflow Furnaces

Connect supply-air duct to supply-air opening on furnace. The supply-air ducts attachment must ONLY be connected to furnace supply/outlet or air conditioning coil casing (when used), when 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 supply side air duct, humidifier, or other accessories. All accessories MUST be connected external to the furnace main casing.

B. Horizontal Furnaces

Connect supply-air duct to supply-air opening on furnace. The supply-air ducts attachment must ONLY be connected to furnace supply/outlet or air conditioning coil casing (when used). DO NOT cut main furnace casing to attach supply side air duct, humidifier, or other accessories. All accessories MUST be connected external to the furnace main casing.

—5—

VENT THROUGH ROOF (CATEGORY I)

DUCTS TO

OUTDOORS

1 SQ IN. PER 4000 BTUH

RETURN

AIR

INTERIOR

HEATED

SPACE

SUPPLY AIR

* Minimum opening size is 100 sq in. with minimum dimensions of 3 in.

†

Minimum of 3 in. when type B-1 vent is used.

Fig. 3—Confined Space: Air for Combustion and Ventilation

12″ MAX

1 SQ IN. PER 1000 BTUH* IN DOOR OR WALL

UNCONFINED SPACE

6″ MIN (FRONT)

1 SQ IN. PER 1000 BTUH* IN DOOR OR WALL

†

12″ MAX

A93387

from an Unconfined Indoor Space

12″ MAX

1 SQ IN. PER 2000 BTUH

DUCTS

OUTSIDE

1 SQ IN. PER 2000 BTUH

12″ MAX

SUPPLY AIR

Minimum dimensions of 3 in.

NOTE:

Use any of the following combinations of openings: A & B C & D D & E F & G

RETURN

AIR

Fig. 4—Confined Space: Air for Combustion and Ventilation

VENT THROUGH ROOF (CATEGORY I)

CONFINED

DUCT

OUTDOORS

SPACE

12″ MAX

″

MAX

1 SQ IN. PER 4000 BTUH

OUTDOORS 1 SQ IN.

PER 4000 BTUH

″

MAX

1 SQ IN. PER 4000 BTUH

A93388

from Outdoors

TABLE 2—MINIMUM FREE AREA OF COMBUSTION AIR OPENING*

376CAV

FURNACE

INPUT

(BTUH)

46,000 100 11.50 4 23.0 6 15.33 5 69,000 100 17.25 5 34.5 7 23.00 6

92,000 100 23.00 6 46.0 8 30.67 7 115,000 115 28.75 7 57.5 9 38.33 7 135,000 135 33.75 7 67.5 10 45.00 8

* Free area shall be equal to or greater than the sum of the areas of all vent connectors in the confined space. Opening area must be increased if other gas appliances in the space require combustion air.

AIR FROM INDOOR

UNCONFINED SPACE

Free Area

of Opening

(Sq. In.)

IV. RETURN AIR CONNECTIONS

The return-air duct must be connected to return air opening as shown in Fig. 1. DO NOT cut into casing sides or back to attach any portion of return-air duct. Bypass humidifier connections should be made at ductwork or coil casing sides exterior to furnace.

WARNING: Do not install furnace on its back. Safety control operation will be adversely affected. Never connect return-air ducts to back of furnace. Failure to follow this warning could result in fire, personal injury, or death.

OUTDOOR AIR THROUGH

VERTICAL DUCTS

Free Area of

Opening and Duct

(Sq. In.)

Round

Pipe

(In. Dia.)

OUTDOOR AIR THROUGH

HORIZONTAL DUCTS

Free Area

of Opening and Duct

(Sq. In.)

Round

Pipe

(In. Dia)

OUTDOOR AIR THROUGH

SINGLE DUCT

Free Area

of Opening and Duct

(Sq. In.)

Round

(In. Dia)

rating plate, MUST be used. A factory accessory floor base is not required when this furnace is installed on manufacturer’s Coil Assembly Part No. CD5 or CK5, or when Coil Box Part No. KCAKC is used.

1. Determine application being installed from Table 3.

2. Construct hold in floor per dimensions specified in Table 3 and Fig. 5.

3. Construct plenum to dimensions specified in Table 3.

4. If downflow subbase (KGASB) is used, install as shown in Fig. 6.

Pipe

If coil assembly CD5, CK5 or Coil Box KCAKC is used, install as shown in Fig. 7.

V. DOWNFLOW INSTALLATION

This furnace is approved for use on combustible materials or wood flooring. A factory accessory floor base, as listed on the furnace

VI. HORIZONTAL ATTIC INSTALLATION

The furnace can be installed on either the left-hand (LH) or right-hand (RH) side. A typical attic installation is shown in Fig. 8.

—6—

FRONT

BACK

FRONT

A. Construct a Working Platform

Constructs a working platform, on location, where all required furnace clearances are met. (See Fig. 2 and 8.)

B. Install Furnace

1. Position furnace in desired location.

B A C K

2. Connect gas supply pipe. See Fig. 8 for typical piping entry.

3. Install field-supplied filter retainers as indicated in Fig. 11 and Table 4 before connecting return-air duct to furnace.

4. Connect supply- and return-air ducts.

5. Install 24- X 24–in. sheet metal shield on platform in front of louvered control panel as shown in Fig. 8.

VII. HORIZONTAL CRAWLSPACE INSTALLATION

A93043

The furnace can be installed horizontally with either LH or RH side up. In a crawlspace, furnace can either be hung from floor joist (see Fig. 10) or installed on suitable blocks or pad. (See Fig.

PLENUM

OPENING

FURNACE

CASING

WIDTH

14–3/16

17–1/2

24–1/2

FLOOR

OPENING

Fig. 5—Floor and Plenum Opening Dimensions

TABLE 3—OPENING DIMENSIONS (IN.)

APPLICATION

Non-Combustible Flooring 12–11/16 19 13–3/8 19–5/8

Combustible Flooring Using KGASB Subbase 11–13/16 19 13–7/16 20–3/8

Combustible Flooring with CD5 or CK5 Coil Assembly or

KCAKC Coil Box

Non-Combustible Flooring 16 19 16–5/8 19–5/8

Combustible Flooring Using KGASB Subbase 15–1/8 19 16–3/4 20–3/8

Combustible Flooring with CD5 or CK5 Coil Assembly or

KCAKC Coil Box

Non-Combustible Flooring 19–1/2 19 20–1/8 19–5/8

Combustible Flooring Using KGASB Subbase 18–5/8 19 20–1/4 20–3/8

Combustible Flooring with CD5 or CK5 Coil Assembly or

KCAKC Coil Box

Non-Combustible Flooring 23 19 23–5/8 19–5/8

Combustible Flooring Using KGASB Subbase 22–1/8 19 23–3/4 20–3/8

Combustible Flooring with CD5 or CK5 Coil Assembly or

KCAKC Coil Box

PLENUM OPENING FLOOR OPENING

ABCD

12–5/16 19 13–5/16 20

15–1/2 19 16–1/2 20

19 19 20 20

22–1/2 19 23–1/2 20

A96283

—7—

FURNACE

(OR COIL CASING

WHEN USED)

COMBUSTIBLE

FLOORING

FURNACE

CD5 OR CK5

COIL ASSEMBLY

OR KCAKC

COIL BOX

COMBUSTIBLE

FLOORING

DOWNFLOW

SUBBASE

SHEET METAL

PLENUM

FLOOR

OPENING

Fig. 6—Furnace, Plenum, and Subbase Installed on a Com-

A96285

bustible Floor

9.) The furnace can be suspended from each corner by hanger bolts (4 each 3/8-in. all-thread rod) cut to desired length, 1- X 3/8–in. flat washer, 3/8–in. lockwasher, and 3/8–in. nut. Dimples are provided for hole locations. (See Fig. 1.)

Since horizontal crawlspace installation is very similar to attic installation, refer to Section VI, “Horizontal Attic Installation”. The installation of a sheet metal shield in front of louvered control panel is covered in Section VI.

For crawlspace installation, this same sheet metal shield must be installed above louvered control panel. Extend sheet metal shield over furnace top far enough to cover gas pipe entry hole.

SHEET METAL

PLENUM

FLOOR

OPENING

Fig. 7—Furnace, Plenum, and Coil Assembly or Coil Box

A96284

Installed on a Combustible Floor

VIII. FILTER ARRANGEMENT

WARNING: Never operate unit without filter access

door removed. Failure to follow this warning could result in fire, personal injury, or death.

LINE CONTACT ONLY PERMISSIBLE BETWEEN LINES FORMED BY INTERSECTIONS OF THE TOP AND TWO SIDES OF THE FURNACE JACKET AND BUILDING JOISTS, STUDS, OR FRAMING.

MANUAL SHUTOFF

GAS VALVE

SEDIMENT

TRAP

GAS ENTRY

″

SHEET METAL

Fig. 8—Typical Attic Installation

—8—

MIN

TYPE-B VENT

30-IN. MIN WORK AREA

A97516

The 2 factory-supplied filters are shipped in the blower compartment. After return-air duct has been connected to furnace, install filters in a V-formation inside return-air plenum. See Fig. 11 and Table 4 for horizontal applications. Horizontal filter retainers must be field supplied. See Fig. 12 for downflow applications.

IX. GAS PIPING

Gas piping must be installed in accordance with national and local codes. Refer to the current edition of the NFGC.

Canadian installations must be installed in accordance with NSCNGPIC and all authorities having jurisdiction.

Refer to Table 5 for recommended gas pipe sizing. Risers should be used to connect to the furnace and the meter.

Fig. 9—Horizontal Installation on Blocks

CAUTION: If a flexible connector is required or al-

lowed by the authority having jurisdiction, black iron pipe shall be installed at the gas valve and extend a minimum of 2 in. outside the furnace casing.

WARNING: Use the proper length of pipes to avoid stress on the gas control manifold. Failure to follow this warning can result in a gas leak, causing fire, explosion, personal injury, or death.

A95235

ANGLE IRON OR EQUIVALENT

(B)

(A)

ROD LOCATION USING DIMPLE LOCATORS (SEE DIMENSIONAL DWG FOR LOCATIONS)

(A) PREFERRED ROD LOCATION (B) ALTERNATE ROD LOCATION

Fig. 10—Horizontal Crawlspace Installation on Hanger Rods

/8-IN. HEX NUT

& WASHER (4)

REQD PER ROD

(B)

(A)

(B)

NOTES:

⁄8-IN. ROD

(A)

(B)

1. A 1 In. clearance minimum between top of furnace and combustible material.

2. The entire length of furnace must be supported when furnace is used in horizontal position.

A96633

—9—

;

;;;

;

;;

;;;;;;

AIRFLOW

12″

TABLE 5—MAXIMUM CAPACITY OF PIPE*

NOMINAL IRON

PIPE SIZE

(IN.)

1/2 0.622 175 120 97 82 73 3/4 0.824 360 250 200 170 151

1 1.049 680 465 375 320 285 1–1/4 1.380 1400 950 770 660 580 1–1/2 1.610 2100 1460 1180 990 900

* Cubic ft of gas per hr for gas pressures 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

4″

10-2 NFPA 54/ANSI Z223.1-1996.

INTERNAL DIAMETER

(IN.)

LENGTH OF PIPE (FT)

10 20 30 40 50

FIELD-SUPPLIED FILTER RETAINERS

Fig. 11—Horizontal Filter Arrangement

TABLE 4—FILTER INFORMATION (IN.)

FURNACE CASING

WIDTH 14-3/16 (2)16X20X1 15–3/8

17-1/2 (2)16X20X1 14–3/4

21 (2)16X20X1 13–3/4

24-1/2 (2)16X20X1 12–1/2

INSTALLATION

POSITION

OF FILTERS

RETURN-AIR

PLENUM

FILTER SIZE AND QUANTITY D

AIRFLOW

A82173

WARNING: Never purge a line into a combustion chamber. Never use matches, candles, flame, or other sources of ignition for to check for gas leakage. Use a soap-and-water solution to check for gas leaks. Failure to follow this warning could result in fire, explosion, personal injury, or death.

Joint compounds (pipe dope) should be applied sparingly and only to the male threads of the joints. This pipe dope must be resistant to the action of propane gas.

An accessible manual shutoff valve MUST be installed upstream of the furnace gas controls and within 72 in. of the furnace. A 1/8-in. NPT plugged tapping, accessible for test gage connection, MUST be installed immediately upstream of the gas supply connection to the furnace and downstream of the manual shutoff valve. Place a ground joint union between the gas control manifold and the manual shutoff.

Install a sediment trap in the riser leading to the furnace. The trap can be installed by connecting a tee to the riser leading from the furnace. Connect a capped nipple into the lower end of the tee. The capped nipple should extend below the level of the gas controls. (See Fig. 13.)

ACCESS DOOR

Fig. 12—Downflow Filter Arrangement

CAUTION: Connect the gas pipe to the furnace using a

backup wrench to avoid damaging gas controls.

A88486

GAS

SUPPLY

MANUAL SHUTOFF VALVE (REQUIRED)

SEDIMENT TRAP

UNION

A89414

Fig. 13—Typical Gas Pipe Arrangement

Piping should be pressure tested in accordance with local and national plumbing and gas codes before the furnace has been attached. If the pressure exceeds 0.5 psig (14-in. wc), the gas supply pipe must be disconnected from the furnace and capped

—10—

TABLE 6—ELECTRICAL DATA

UNIT

SIZE

024050 115–60–1 127 104 6.6 14 42 15 036050 115–60–1 127 104 8.1 14 34 15 024070 115–60–1 127 104 6.7 14 42 15 036070 115–60–1 127 104 8.4 14 33 15 036096 115–60–1 127 104 9.2 14 30 15 048096 115–60–1 127 104 10.2 14 28 15 048115 115–60–1 127 104 10.1 14 28 15 060115 115–60–1 127 104 13.3 12 33 20 066115 115–60–1 127 104 15.2 12 29 20 060135 115–60–1 127 104 14.3 12 31 20

* Permissible limits of voltage range at which unit will operate satisfactorily.

† Time-delay type is recommended. ‡ Length shown is a measured 1 way along wire path between unit and service panel for maximum 2 percent voltage drop.

VOLTS— HERTZ—

PHASE

OPERATING

VOLTAGE RANGE

Maximum* Minimum*

MAXIMUM

UNIT

AMPS

MIN

WIRE

GAGE

MAXIMUM

WIRE LENGTH (FT)‡

FUSE OR CKT BKR

MAXIMUM

AMPS†

before the pressure test. If the test pressure is equal to or less than

0.5 psig (14-in. wc), turn off electric shutoff switch located on the gas valve before the test. It is recommended that the ground joint union be loosened before pressure testing.

After all connections have been made, purge the lines and check for gas leakage with regulated gas supply pressure.

X. ELECTRICAL CONNECTIONS

This section covers the electrical connections necessary to install the 376C503 furnace.

A. 115–V Wiring

Refer to the unit rating plate or Table 6 for equipment electrical requirements. The control system requires an earth ground for proper operation.

CAUTION: Do not connect aluminum wire between disconnect switch and furnace. Use only copper wire.

Make all electrical connections in accordance with the current edition of the National Electrical Code (NEC) ANSI/NFPA 70-1999 and any local codes or ordinances that might apply. For Canadian installations, all electrical connections must be made in accordance with Canadian Electrical Code CSA C22.1, or authorities having jurisdiction.

NOTE: Proper polarity must be maintained for 115-v wiring. If polarity is incorrect, control board status code indicator light will flash rapidly and the furnace will not operate.

WARNING: The cabinet MUST have an uninterrupted or unbroken ground according to NEC, ANSI/NFPA 70-1999 and Canadian Electrical Code, CSA C22.1 or local codes to minimize personal injury if an electrical fault should occur. This may consist of electrical wire or conduit approved for electrical ground when installed in accordance with existing electrical codes. Do not use gas piping as an electrical ground. Failure to follow this warning could result in electrical shock, fire, or death.

B. 24–V Wiring

Make field 24-v connections at the 24-v terminal strip. (See Fig.

14.) Connect terminal Y as shown in Fig. 15 or proper cooling operation in cooling mode. Use only AWG No. 18, color-coded, copper thermostat wire.

The 24-v circuit contains an automotive-type, 3-amp fuse located on the main control board. Any direct shorts during installation, service, or maintenance could cause this fuse to blow. If fuse replacement is required, use ONLY a 3-amp fuse of identical size.

C. Accessories

1. Electronic Air Cleaner (EAC) Two quick-connect terminals marked EAC-1 and EAC-2 are provided for EAC connection. (See Fig. 14.) These terminals are energized with 115-v, (1.5-amp maximum) during blower motor operation.

2. Humidifier (HUM) A quick-connect terminal (HUM) and screw terminal (C

OM)

are provided for 24-v humidifier connection. (See Fig. 16.) HUM terminal is energized with 24-v (0.5-amp maximum) after inducer pressure switch closes.

WARNING: DO NOT connect furnace control HUM terminal to HUM (humidifier) terminal on Thermidistat™, Zone Controller or similar device. See Thermidistat, Zone Controller, thermostat, or controller manufacturer’s instructions for proper connection. A failure to follow this warning could result in fire.

NOTE: A field-supplied, 115-v controlled relay connected to EAC terminals may be added if humidifier operation is desired during blower operation.

XI. VENTING

Refer to the national or local installation code such as NFGC in the United States, or the NSCNGPIC in Canada for proper vent sizing and installation requirements. Use the enclosed Installation Instructions (Single-Stage Vent Tables for Category I Fan-Assisted Furnaces) for a quick, easy reference. After fully assembling the vent connector to the furnace flue collar, securely fasten the vent connector to the collar with two fieldsupplied, corrosion-resistant, sheet metal screws located 180° apart and midway up the collar. The horizontal portion of the venting system shall maintain a minimum of 1/4-in. upward slope per linear ft and it shall be rigidly supported every 5 ft or less with hangers or straps to ensure that there will be no movement after installation.

START-UP PROCEDURES, ADJUSTEMENT, AND

SAFETY CHECK

I. GENERAL NOTE: Proper polarity must be maintained for 115-v wiring. If

polarity is incorrect, control status indicator light will flash rapidly and furnace will not operate. The furnace must have a 115-v power supply properly connected and grounded. Proper polarity must be maintained for correct operation. Thermostat wire connections at R, W, C, and Y must be made at the 24-v terminal block on the furnace control. The gas service pressure must not exceed 0.5 psig (14-in. wc), but must be no less than 0.16 psig (4.5-in. wc).

—11—

BLOWER OFF DELAY ADJUSTMENT SWITCH

TEST/TWIN

SEC-1

3-AMP FUSE

COOL

HEAT

115-VAC (L1)

POWER SUPPLY

HOT SURFACE

IGNITOR CONNECTOR

→

Before operating the furnace, check each manual reset switch for continuity. If necessary, press the button to reset the switch.

The blower compartment door must be in place to complete the 115-v circuit to the furnace.

CAUTION: This furnace is equipped with 2 manual reset limit switches in the gas control area. The switches will open and shut off power to the gas valve if a flame rollout or an overheating condition occurs in the gas control area. DO NOT bypass the switches. Correct inadequate combustion air supply problem and reset the switches.

II. SEQUENCE OF OPERATION

CAUTION: Furnace control must be grounded for

proper operation, or control will lockout. Control is grounded through green wire routed to gas valve and burner bracket screw.

Using the schematic diagram shown in Fig. 16, follow the sequence of operation through the different modes. Read and follow the wiring diagram very carefully.

NOTE: If there is a power interruption and any thermostat call, the control will initiate a 90-sec blower only on period before starting another cycle.

G R Y

Com

24V HUM

115-VAC (L2) NEUTRAL CONNECTION

INDUCER MOTOR CONNECTOR

24-V THERMOST AT TERMINALS

HUMIDIFIER TERMINAL (24-VAC 0.5 AMP MAX)

LED OPERATION & DIAGNOSTIC LIGHT

HARNESS CONNECTOR

24-V TRANSFORMER SEC-2 SPARE-1 BLOWER SPEED

SELECTION TERMINALS SPARE-2

EAC-1 (BLACK) EAC-ELECTRONIC AIR CLEANER

TERMINALS (115-VAC 1 AMP MAX) EAC-2 (WHITE)

Fig. 14—Furnace Control

1. Heating mode

NOTE: Ignition sequence will repeat 3 additional time before a lockout occurs. Lockout automatically resets after 3 hr, or can be manually reset by turning 115–v off (not at thermostat) for 3 sec minimum, then on again.

A00292

When the thermostat “calls for heat,” the R-W circuit closes. The furnace control performs a self-check, verifies the pressure switch contacts are open, and starts inducer motor.

a. Prepurge period—As the inducer motor comes up to

speed, the pressure switch contacts close to begin a 15-sec prepurge period.

b. Igniter warm-up—At the end of the prepurge period, the

igniter is energized for a 17-sec igniter warm-up period.

c. Ignition sequence—When the igniter warm-up period is

completed, the gas valve opens, permitting gas flow to the burners where it is ignited. After 5 sec, the igniter is de-energized and a 2-sec flame-sensing period begins.

d. HUM terminal is energized with the gas valve. See

Accessories in the Electrical Connections section.

e. Flame-sensing—When burner flame is sensed, the con-

trol begins the blower on delay period and continues holding the gas valve open. If burner flame is not sensed, the control closes the gas valve and repeats ignition cycle.

—12—

f. Blower on delay—Forty-five sec after burner flame is

proven, the blower motor is energized on heating speed. Simultaneously, terminals HUM and C

OM-24V for hu-

midifier, and EAC-1 and EAC-2 for EAC are energized. If jumper is on pin 6 and pin 9, blower on delay period is 66 sec.

g. Blower off delay—When the thermostat is satisfied, the

circuit between R-W is broken, de-energizing the gas valve stopping gas flow to the burners. The blower motor and EAC remain energized 90, 135, 180, or 225 sec (depending on the blower off-time selection). The furnace is factory set for a 135-sec blower off delay period.

h. Post-purge—The inducer motor remains energized 5 sec

after the burners are extinguished. If jumper is on pin 6 and pin 9, the post-purge period is 15 sec.

2. Cooling mode When the thermostat “calls for cooling,” R-G and R-Y circuits close. The R-Y circuit starts the outdoor condensing unit and the combined R-Y and R-G circuits start the furnace blower motor on cooling speed. The EAC-1 terminal is energized with 115–v when the blower is operating on cooling speed. When the thermostat is satisfied, R-G and R-Y circuits are broken. The furnace blower and EAC continue operating on cooling speed for an additional 90 sec.

NOTE: EAC-1 terminal in energized with 115-v whenever blower is operating.

3. Continuous blower mode When the R-G circuit is made, the blower motor operates on heating speed. During a call for heat, the blower stops, allowing the furnace heat exchangers to heat up more quickly, then restarts at the end of the 45-sec blower on delay period. If jumper is on pin 6 and pin 9, the blower on delay is 66 sec. The blower reverts to continuous operation after the heating cycle is completed.

When the thermostat “calls for cooling,” the blower operates on cooling speed. When the thermostat is satisfied, the blower operates an additional 90 sec before reverting back to continuous operation on heating speed.

4. Heat pump mode When installed with a heat pump, the furnace control automatically changes the timing sequence to avoid long blower off time during demand defrost cycles. When the W-Y or W-Y-G thermostat inputs are received at the same time, the control changes the blower to heating speed or starts the blower if it was off, and begins a heating cycle. The blower remains on until the end of the prepurge period, then shuts off until the end of the ignition warm-up and trial for ignition periods (a total of 24 sec). The blower then comes back on at heating speed. When the W input signal disappears, the control begins the normal inducer post-purge period and the blower changes to cooling speed after a 1-sec delay. If the W-Y-G signals disappear at the same time, the blower remains on for the selected heating blower off delay period and the inducer goes through its normal post-purge period. If the W-Y inputs should disappear, leaving the G signal input, the control goes into continuous blower and the inducer remains on for the normal post-purge period. Anytime the control senses false flame, the control locks out of the heating mode. This occurs because the control cannot sense the W input due to the false flame signal, and as a result, sees only the Y input and goes into cooling mode blower off delay. All other control functions remain in standard format.

NOTE: EAC-1 terminal is energized whenever blower operates. HUM terminal is only energized when gas valve is energized.

FIVE WIRE

THREE-WIRE

HEATING-ONLY

BLOWER DOOR SWITCH

BLK

WHT

115-V FIELD-

SUPPLIED

DISCONNECT

BLK

WHT

GND

AUXILIARY J-BOX

FIELD 24-V WIRING FIELD 115-, 208/230-, 460-V WIRING FACTORY 24-V WIRING FACTORY 115-V WIRING

GND

FURNACE

NOTE 2

O N T

R O

24-V

TERMINAL

BLOCK

WCR GY

NOTE 1

NOTES: Connect Y-terminal in furnace as shown for proper blower operation.

1. Some thermostats require a "C" terminal connection as shown.

2. If any of the original wire, as supplied, must be replaced, use

3. same type or equivalent wire.

THERMOSTAT TERMINALS

CONDENSING UNIT

TWO WIRE

Fig. 15—Heating and Cooling Application Wiring Diagram

FIELD-SUPPLIED DISCONNECT

208/230- OR 460-V THREE PHASE

208/230-V SINGLE PHASE

GND

A99521

—13—

Fig. 16—Furnace Wiring Diagram

A00304

PCB

BLOWER OFF DELAY

SELECTION CHART

90 SEC 135 SEC 180 SEC 225 SEC

GVR

HI/LO

RELAY

SEC-1

SEC-2

PL1

321 6

LED

TEST/TWIN

BLOWER

OFF

DELAY

G R Y W C

HUM

HSIR IDR BLW R

BLOWER SPEED SELECT

FU1

COOL

HEAT

PL3

PL2

VAC

120

PR1

1 2

1 2 3

PR2

24 VAC-3A

FUSE

SPARE-2

SPARE-1

EAC-1

EAC-2

1.5 AMP

PL5

WHT

BLK

WHT

BLK

HSI

BLK

WHT

WHT (COM)

RED (LO)

BLU (MED LO)

NOTE #7

START

BLWM

YEL (MED HI)

BLK (HI)

BRN

TRAN

BLU

RED

BLK

WHT

WHT (COM)

CAP

RED

ORN

FUSED DISCONNECT

SWITCH (WHEN REQ’D)

NOTE #4

FU2

BLK

WHT

LEGEND

ALS AUXILIARY LIMIT SWITCH, OVERTEMP. -MANUAL RESET, SPST-(N.C.) BLWR BLOWER MOTOR RELA Y, SPST-(N.O.) BLWM BLOWER MOTOR BVSS BLOCKED VENT SHUTOFF SWITCH, SPST - (N.C.) CAP CAP ACITOR CPU MICROPROCESSOR AND CIRCUITRY DSS DRAFT SAFEGUARD SWITCH EAC-1 ELECTRONIC AIR CLEANER CONNECTION (115 VAC 1.5 AMP MAX.) EAC-2 ELECTRONIC AIR CLEANER CONNECTION (COMMON) FL FUSIBLE LINK FRS FLAME ROLLOUT SW . -MANU AL R ESET, SPST-(N.C.) FSE FLAME PROVING ELECTRODE FU1 FUSE, 3 AMP, A UT OM OTIVE BLADE TYPE, FACTORY INST ALLED FU2 FUSE OR CIRCUIT BREAKER CURRENT INTERRUPT DEVICE

(FIELD INSTALLED & SUPPLIED) GV GAS VALVE-REDUNDANT OPERATORS GVR GAS VALVE RELAY , DPST -(N.O.) HI/LO BLOWER MOTOR SPEED CHANGE RELAY, SPDT HSI HOT SURFAC E IGN ITOR (115 VAC ) HSIR HOT SURFACE IGNITOR RELAY, SPST-(N.O.) HUM 24VAC HUMIDIFIER CONNECTION (.5 AMP. MAX.) IDM INDUCED DRAFT MOTOR IDR INDUCED DRAFT RELAY, SPST-(N.O.) ILK BLOWER ACCESS PANEL INTERLOCK SWITCH, SPST -(N.O.) JB JUNCTION BOX LED LIGHT-EMITTING DIODE FOR STATUS CODES LGPS LOW GAS PRESSURE SWITCH, SPST-(N.O.) LS LIMIT SWITCH, A UT O RESET, SPST(N.C.) OL AUTO-RESET INTERNAL MOTOR OVERLOAD TEMP. SW.

PCB PRINTED CIRCUIT BOARD PL1 9-CIRCUIT CONNECTOR PL2 2-CIRCUIT PCB CONNECTOR PL3 3-CIRCUIT ID M CONNECT O R PL5 2-CIRCUIT HSI/PCB CONNECTOR PRS PRESSURE SWITCH, SPST-(N.O.) TEST/TWIN COMPONENT TEST & TWIN TERMINAL TRAN TRANSFO RM ER -115VAC/24VAC

JUNCTION UNMARKED TERMI NAL PCB TERMINAL FACTORY WIRING (115VAC) FACTORY WIRING (24VAC) FIELD WIRING (115VAC) FIELD WIRING (24VAC) CONDUCTOR ON PCB FIELD WIRING TERMINAL FIELD GROUND EQUIPMENT GROUND FIELD SPLICE PLUG RECEPTACLE

BLWR

HI/LO

TO 115VAC FIELD DISCONNECT

NOTE #4

EQUIPMENT GROUND

SPARE-2

HEAT

SPARE-1

COOL

NOTE #7

COM

HSIR

EAC-1

START

COM

MED HI

MED LO

BLWM

SCHEMATIC DIAGRAM

(NATURAL GAS & PRO PANE)

EAC-2

HSI

PL52

PL2

PL3

PR2

115VA C

PR1

TRAN

24VAC

IDR

TEST/TWIN

FU1

NOTE #6

CAP

PL1

FSE

CPU

HSIR

IDR

BLWR

GVR-2

SEC-1

HI/LO

GVR

SEC-2

NOTES:

322869-101 REV. H

1. If any of the original equipment wire is replaced use wire rated for 105°C.

2. Inducer (IDM) and blower (BLWM) motors contain internal auto-reset thermal overload s witches (OL).

3. Blower motor speed selections are for a verage conditions, see installation instructions for details on optimum speed selection.

4. Use only copper wire between the disconnect sw itch and the furnace junction bo x (JB ).

5. This wire must be connected to furnace sheetmetal for control to detect flame.

6. Replace only with a 3 amp fuse.

7. Yellow lead not on all motors.

8. Blower-on delay, gas heating 45 seco nds , cooling or heat pu m p 2 se co nds .

9. Blower-off delay, gas heating 90, 135, 180 or 225 sec on ds , co oling or heat pu m p 90 seco nds . (135 seconds only on some models)

10. Ignition-lock o u t will occur a f te r f o u r c o n s ecutive u nsucce s s f u l t ria ls -f o r -ignition. C ontrol will auto-reset after thre e hours.

11. When us e d , a uxiliary lim it s witch (ALS) is on s ome do wnflow models only. W h en used, FL is o n upflow models only.

12. Some models may have spad e quic k co nn e ct terminals.

13. Factory connected when LGPS is not used.

14. Factory connected when BVSS is not used. BVSS used when Chimney Adapter Accessory Kit is installed .

15. Gas valve leads are interchangeable on single stage valves .

BLK

SW2

SW1

7 1

HUM

IDM

ILK

DSS

BVSS

PRS

ILK

NEUTRAL

IDM

(WHEN USED)

NOTE #14

NOT USED NOT USED

NOT USED

FSE

BLU

PRS

DSS

BVSS

(WHEN USED)

NOTE #14

WHT

(NOT ON ALL MODELS)

NOTE #9

FRS1

FRS2

NOTE #12

ORN

ALS

(WHEN USED)

ORN

NOTE #11

LGPS

(WHEN USED)

NOTE #13

NOTE #14

NOTE #11

GVR-1

NOTE #14

ALS

(WHEN USED)

NOTE #13

LGPS (WHEN USED)

NOTE #13

YEL

FRS1

FRS2

(WHEN USED) NOTE #11

GRN/YEL

GND

NOTE #5

GRN/YEL

NOTE #5

GRN/YEL

NOTE #15

—14—

III. START-UP PROCEDURES

1. Purge gas lines—After all connections have been made, purge the lines and check for leaks.

WARNING: Never purge a line into a combustion chamber. Never use matches, candles, flame, or other sources of ignition to check for gas leakage. Use a soap-and-water solution to check for gas leaks. Failure to follow this warning could result in fire, explosion, personal injury, or death.

2. Component test—The furnace control allows all components, except gas valve, to be run for a short period of time. This feature helps diagnose a system problem in case of a component failure. To initiate component test procedure, short (jumper) the TEST 3/16-in. quick connect terminal on control (adjacent to diagnostic light) and the C

OM-24V

terminal on furnace thermostat connection block for approximately 2 sec. (See Fig. 14.)

NOTE: Component test feature will not operate if any thermostat signal is present at control.

Component test sequence is as follows.

a. Momentarily jumper TEST and C

OM-24V terminals until

LED goes off. b. LED will display previous status code 4 times. c. Inducer motor starts and continues to run for entire

component test. d. Hot surface igniter is energized for 15 sec, then de-

energized.

e. Blower motor operates on cooling speed for 10 sec, then

stops. f. Blower motor operates on heating speed for 10 sec, then

stops. g. Inducer motor stops.

3. To operate furnace, follow procedures on operating instruction label attached to furnace.

4. With furnace operating, set thermostat below room temperature and observe that furnace goes off. Set thermostat above room temperature and observe that furnace restarts.

IV. ADJUSTMENTS

1. Set gas input rate Furnace gas input rate on rating plate is for installations at altitudes up to 2000 ft. Furnace input rate must be within ±2 percent of input on furnace rating plate.

a. Determine natural gas orifice size and manifold pressure

for correct input. (1.) Obtain average yearly gas heat value (at installed

altitude) from local gas supplier.

(2.) Obtain average yearly gas specific gravity from

local gas supplier.

(3.) Verify furnace model. Table 7 can only be used for

model 376CAV Furnaces.

(4.) Find installation altitude in Table 7.

NOTE: For Canada altitudes of 2000 to 4500 ft, use U.S.A. altitudes of 2001 to 3000 ft in Table 7.

(5.) Find closest natural gas heat value and specific

gravity in Table 7.

(6.) Follow heat value and specific gravity lines to point

of intersection to find orifice size and manifold pressure settings for proper operation.

EXAMPLE: (0–2000 ft altitude) Heating value = 1025 Btu/cu ft Specific gravity = 0.62 Therefore: Orifice No. 43*

Manifold pressure 3.6-in. wc * Furnace is shipped with No. 43 orifices. In this example all main burner orifices are the correct size and do not need to be changed to obtain proper input rate.

(7.) Check and verify burner orifice size in furnace.

NEVER ASSUME ORIFICE SIZE. ALWAYS CHECK AND VERIFY.

NOTE: If orifice hole appears damaged or it is suspected to have been redrilled, check orifice hole with a numbered drill bit of correct size. Never redrill an orifice. A burr-free and squarely aligned orifice hole is essential for proper flame characteristics.

BURNER

ORIFICE

A93059

CAUTION: DO NOT redrill orifices. Improper drilling (burrs, out-of-round holes, etc.) can cause excessive burner noise and misdirection of burner flames. This can result in flame impingement of burners and heat exchangers causing failures.

b. Adjust manifold pressure to obtain input rate.

(1.) Remove regulator adjustment seal cap. (See Fig.

17.)

(2.) Turn adjusting screw, counterclockwise (out) to

decrease manifold pressure or clockwise (in) to increase manifold pressure.

NOTE: This furnace has been approved for a manifold pressure of 3.2-in. wc to 3.8-in. wc when installed at altitudes up to 2000 ft. For altitudes above 2000 ft, the manifold pressure can be adjusted from 2.0-in. wc to 3.8-in. wc.

CAUTION: DO NOT bottom out gas valve regulator adjusting screw. This can result in unregulated manifold pressure and result in excess overfire and heat exchanger failures.

(3.) After correct manifold pressure is obtained, replace

gas valve regulator adjustment screw cap and verify adjusted gas input rate using method outlined in item c.

—15—

TABLE 7—MODEL 376CAV ORIFICE SIZE† AND MANIFOLD PRESSURE FOR CORRECT INPUT

(TABULATED DATA BASED ON 23,000 BTUH PER BURNER, DERATED 4 PERCENT FOR EACH 1000 FT ABOVE SEA LEVEL)*

ALTITUDE

RANGE

(FT)

2000

U.S.A. and Canada

ALTITUDE

RANGE

(FT)

U.S.A.

Altitudes

2001

3000

Canada

Altitudes

2000

U.S.A. and Canada

4500

ALTITUDE

RANGE

(FT)

3001

4000

U.S.A. Only

ALTITUDE

RANGE

(FT)

4001

5000

U.S.A. Only

* For size 060135 only, input is 22,500 Btuh per burner. Deduct 0.1-in. wc from manifold pressure shown in table. Change orifice size if manifold pressure falls below 3.2-in. wc on altitudes up to 2000 ft, otherwise change orifice size if manifold pressure falls below 2.0-in. wc. †Orifice sizes shown in SHADING are factory installed.

AVG GAS

HEAT VALUE

(BTU/CU FT)

850 41 3.6 41 3.7 41 3.8 40 3.6 40 3.8 875 42 3.8 41 3.5 41 3.6 41 3.7 41 3.8 900 42 3.5 42 3.7 42 3.8 41 3.5 41 3.6 925 42 3.4 42 3.5 42 3.6 42 3.7 42 3.8 950 42 3.2 42 3.3 42 3.4 42 3.5 42 3.6

975 43 3.7 43 3.8 42 3.2 42 3.3 42 3.4 1000 43 3.5 43 3.6 43 3.7 42 3.2 42 3.3 1025 43 3.3 43 3.4 43 3.6 43 3.7 43 3.8 1050 43 3.2 43 3.3 43 3.4 43 3.5 43 3.6 1075 44 3.5 44 3.6 43 3.2 43 3.3 43 3.4 1100 44 3.3 44 3.4 44 3.5 43 3.2 43 3.3

AVG GAS

HEAT VALUE

(BTU/CU FT)

775 42 3.7 42 3.8 41 3.5 41 3.6 41 3.8

800 42 3.4 42 3.6 42 3.7 42 3.8 41 3.5

825 42 3.2 42 3.3 42 3.5 42 3.6 42 3.7

850 43 3.7 43 3.8 42 3.3 42 3.4 42 3.5

875 43 3.5 43 3.6 43 3.7 42 3.2 42 3.3

900 43 3.3 43 3.4 43 3.5 43 3.7 43 3.8

925 43 3.1 43 3.2 43 3.4 43 3.5 43 3.6

950 43 3.0 43 3.1 43 3.2 43 3.3 43 3.4

975 43 2.8 43 2.9 43 3.0 43 3.1 43 3.2 1000 43 2.7 43 2.8 43 2.9 43 3.0 43 3.1 1025 43 2.6 43 2.6 43 2.7 43 2.8 43 2.9

AVG GAS

HEAT VALUE

(BTU/CU FT)

750 42 3.4 42 3.6 42 3.7 42 3.8 41 3.5

775 42 3.2 42 3.3 42 3.5 42 3.6 42 3.7

800 43 3.7 43 3.8 42 3.2 42 3.3 42 3.4

825 43 3.5 43 3.6 43 3.7 43 3.8 42 3.2

850 43 3.3 43 3.4 43 3.5 43 3.6 43 3.7

875 43 3.1 43 3.2 43 3.3 43 3.4 43 3.5

900 43 2.9 43 3.0 43 3.1 43 3.2 43 3.3

925 43 2.8 43 2.9 43 3.0 43 3.0 43 3.1

950 43 2.6 43 2.7 43 2.8 43 2.9 43 3.0

975 43 2.5 43 2.6 43 2.7 43 2.7 43 2.8 1000 43 2.4 43 2.4 43 2.5 43 2.6 43 2.7

AVG GAS

HEAT VALUE

(BTU/CU FT)

725 42 3.2 42 3.3 42 3.5 42 3.6 42 3.7

750 43 3.7 43 3.8 42 3.2 42 3.3 42 3.4

775 43 3.4 43 3.6 43 3.7 43 3.8 42 3.2

800 43 3.2 43 3.3 43 3.5 43 3.6 43 3.7

825 43 3.0 43 3.1 43 3.2 43 3.4 43 3.5

850 43 2.9 43 3.0 43 3.1 43 3.2 43 3.3

875 43 2.7 43 2.8 43 2.9 43 3.0 43 3.1

900 43 2.6 43 2.6 43 2.7 43 2.8 43 2.9

925 43 2.4 43 2.5 43 2.6 43 2.7 43 2.8

950 43 2.3 43 2.4 43 2.5 43 2.5 43 2.6

0.58 0.60 0.62 0.64 0.66

Orifice

no.

Orifice

no.

Orifice

no.

Orifice

no.

Manifold

Pressure

0.58 0.60 0.62 0.64 0.66 Manifold

Pressure

0.58 0.60 0.62 0.64 0.66 Manifold

Pressure

0.58 0.60 0.62 0.64 0.66 Manifold

Pressure

Orifice

no.

Orifice

no.

Orifice

no.

Orifice

no.

SPECIFIC GRAVITY OF NATURAL GAS

Manifold

Pressure

SPECIFIC GRAVITY OF NATURAL GAS

Manifold

Pressure

SPECIFIC GRAVITY OF NATURAL GAS

Manifold

Pressure

SPECIFIC GRAVITY OF NATURAL GAS

Manifold

Pressure

Orifice

no.

Orifice

no.

Orifice

no.

Orifice

no.

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Orifice

no.

Orifice

no.

Orifice

no.

Orifice

no.

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Orifice

no.

Orifice

no.

Orifice

no.

Orifice

no.

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

—16—

TABLE 7—MODEL 376CAV ORIFICE SIZE† AND MANIFOLD PRESSURE FOR CORRECT INPUT (CONTINUED)

(TABULATED DATA BASED ON 23,000 BTUH PER BURNER, DERATED 4 PERCENT FOR EACH 1000 FT ABOVE SEA LEVEL)*

ALTITUDE

RANGE

(FT)

5001

6000

U.S.A. Only

ALTITUDE

RANGE

(FT)

6001

7000

U.S.A. Only

ALTITUDE

RANGE

(FT)

7001

8000

U.S.A. Only

ALTITUDE

RANGE

(FT)

8001

9000

U.S.A. Only

AVG GAS

HEAT VALUE

AT ALTITUDE

(BTU/CU FT)

700 43 3.7 43 3.8 42 3.2 42 3.3 42 3.4 725 43 3.4 43 3.6 43 3.7 43 3.8 42 3.2 750 43 3.2 43 3.3 43 3.4 43 3.5 43 3.6 775 43 3.0 43 3.1 43 3.2 43 3.3 43 3.4 800 43 2.8 43 2.9 43 3.0 43 3.1 43 3.2 825 43 2.7 43 2.7 43 2.8 43 2.9 43 3.0 850 43 2.5 43 2.6 43 2.7 43 2.8 43 2.8 875 43 2.4 43 2.4 43 2.5 43 2.6 43 2.7 900 43 2.2 43 2.3 43 2.4 43 2.5 43 2.5 925 43 2.1 43 2.2 43 2.3 43 2.3 43 2.4 950 48 3.8 43 2.1 43 2.1 43 2.2 43 2.3 975 48 3.6 48 3.7 43 2.0 43 2.1 43 2.2

1000 48 3.4 48 3.5 48 3.6 48 3.7 43 2.1

AVG GAS HEAT VALUE AT ALTITUDE

(BTU/CU FT)

650 43 3.7 43 3.8 42 3.2 42 3.3 42 3.5 675 43 3.4 43 3.5 43 3.7 43 3.8 42 3.2 700 43 3.2 43 3.3 43 3.4 43 3.5 43 3.6 725 43 3.0 43 3.1 43 3.2 43 3.3 43 3.4 750 43 2.8 43 2.9 43 3.0 43 3.1 43 3.2 775 43 2.6 43 2.7 43 2.8 43 2.9 43 3.0 800 43 2.4 43 2.5 43 2.6 43 2.7 43 2.8 825 43 2.3 43 2.4 43 2.5 43 2.5 43 2.6 850 43 2.2 43 2.2 43 2.3 43 2.4 43 2.5 875 43 2.0 43 2.1 43 2.2 43 2.3 43 2.3

AVG GAS HEAT VALUE AT ALTITUDE

(BTU/CU FT)

625 43 3.4 43 3.6 43 3.7 43 3.8 42 3.2 650 43 3.2 43 3.3 43 3.4 43 3.5 43 3.6 675 43 3.0 43 3.1 43 3.2 43 3.3 43 3.4 700 43 2.7 43 2.8 43 2.9 43 3.0 43 3.1 725 43 2.6 43 2.6 43 2.7 43 2.8 43 2.9 750 43 2.4 43 2.5 43 2.6 43 2.6 43 2.7 775 43 2.2 43 2.3 43 2.4 43 2.5 43 2.5 800 43 2.1 43 2.2 43 2.2 43 2.3 43 2.4 825 48 3.7 43 2.0 43 2.1 43 2.2 43 2.2 850 48 3.5 48 3.6 48 3.7 43 2.1 43 2.1

AVG GAS HEAT VALUE AT ALTITUDE

(BTU/CU FT)

600 43 3.2 43 3.3 43 3.4 43 3.5 43 3.6 625 43 3.0 43 3.1 43 3.2 43 3.3 43 3.4 650 43 2.7 43 2.8 43 2.9 43 3.0 43 3.1 675 43 2.5 43 2.6 43 2.7 43 2.8 43 2.9 700 43 2.4 43 2.4 43 2.5 43 2.6 43 2.7 725 43 2.2 43 2.3 43 2.3 43 2.4 43 2.5 750 43 2.0 43 2.1 43 2.2 43 2.3 43 2.3 775 48 3.6 48 3.7 43 2.1 43 2.1 43 2.2 800 48 3.4 48 3.5 48 3.6 48 3.7 43 2.0

0.58 0.60 0.62 0.64 0.66

Orifice

No.

Orifice

No.

Orifice

No.

Orifice

No.

Manifold

Pressure

0.58 0.60 0.62 0.64 0.66 Manifold

Pressure

0.58 0.60 0.62 0.64 0.66 Manifold

Pressure

0.58 0.60 0.62 0.64 0.66 Manifold

Pressure

Orifice

No.

Orifice

No.

Orifice

No.

Orifice

No.

SPECIFIC GRAVITY OF NATURAL GAS

Manifold

Pressure

SPECIFIC GRAVITY OF NATURAL GAS

Manifold

Pressure

SPECIFIC GRAVITY OF NATURAL GAS

Manifold

Pressure

SPECIFIC GRAVITY OF NATURAL GAS

Manifold

Pressure

Orifice

No.

Orifice

No.

Orifice

No.

Orifice

No.

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Orifice

No.

Orifice

No.

Orifice

No.

Orifice

No.

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Orifice

No.

Orifice

No.

Orifice

No.

Orifice

No.

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

Manifold

Pressure

—17—

TABLE 7—MODEL 376CAV ORIFICE SIZE† AND MANIFOLD PRESSURE FOR CORRECT INPUT (CONTINUED)

(TABULATED DATA BASED ON 23,000 BTUH PER BURNER, DERATED 4 PERCENT FOR EACH 1000 FT ABOVE SEA

ALTITUDE

RANGE

(FT)

9001

10,000

U.S.A. Only

AVG GAS HEAT VALUE AT ALTITUDE

(BTU/CU FT)

575 43 3.0 43 3.1 43 3.2 43 3.3 43 3.4 600 43 2.7 43 2.8 43 2.9 43 3.0 43 3.1 625 43 2.5 43 2.6 43 2.7 43 2.8 43 2.8 650 43 2.3 43 2.4 43 2.5 43 2.6 43 2.6 675 43 2.1 43 2.2 43 2.3 43 2.4 43 2.4 700 48 3.8 43 2.1 43 2.1 43 2.2 43 2.3 725 48 3.5 48 3.6 48 3.7 43 2.1 43 2.1 750 49 3.8 48 3.4 48 3.5 48 3.6 48 3.7 775 49 3.6 49 3.7 49 3.8 48 3.4 48 3.5

0.58 0.60 0.62 0.64 0.66

Orifice

No.

Manifold Pressure

Orifice

No.

SPECIFIC GRAVITY OF NATURAL GAS

Manifold Pressure

Orifice

No.

Manifold

Pressure

Orifice

No.

Manifold

Pressure

Orifice

No.

Manifold

Pressure

(4.) Burner flame should be clear blue, almost transpar-

ent. (See Fig. 18.)

c. Verify natural gas input rate by clocking gas meter.

NOTE: High -Altitude Adjustment UNITED STATES

At installation altitudes above 2000 ft, this furnace has been approved for a 4 percent derate for each 1000 ft above sea level. See Table 8 for derate multiplier factor.

Fig. 17—Redundant Automatic Gas Control Valve

→

BURNER FLAME

MANIFOLD

Fig. 18—Burner Flame

BURNER

A00238

A89020

—18—

TABLE 8—ALTITUDE DERATE MULTIPLIER FOR U.S.A.

ALTITUDE

(FT)

0—2000 0 1.00 2001—3000 8—12 0.90 3001—4000 12—16 0.86 4001—5000 16—20 0.82 5001—6000 20—24 0.78 6001—7000 24—28 0.74 7001—8000 28—32 0.70 8001—9000 32—36 0.66

9001—10,000 36—40 0.62

* Derate multiplier factor is based on midpoint altitude for altitude range.

EXAMPLE:

92,000 BTUH INPUT FURNACE INSTALLED AT 4300 FT.

Furnace Input

Rate at

Sea Level

92,000 0.82 75,440

PERCENT OF

DERATE

Derate

Multiplier

Factor

DERATE MULTIPLIER FACTOR FOR U.S.A.*

Furnace Input Rate

at Installation

Altitude

CANADA At installation altitudes from 2000 to 4500 ft, this furnace must be

derated 10 percent by an authorized Gas Conversion Station. To determine correct input rate for altitude, see example above and use 0.90 as derate multiplier factor.

a. Turn off all other gas appliances and pilots. b. Start furnace and let operate for 3 minutes. c. Measure time (in sec) for gas meter test dial to complete

1 revolution. d. Refer to Table 9 for cu ft of gas per hr. e. Multiply gas rate (cu ft/hr) X heating value (Btu/cu ft)

using natural gas heating value from local gas

utility/supplier.

EXAMPLE: (0–2000 ft altitude) Btu heating input = Btu/cu ft X cu ft/hr Heating value of gas = 1050 Btu/cu ft Time for 1 revolution of 2-cu ft dial = 82 sec Gas rate = 88 cu ft/hr (from Table 9) Btu heating input = 88 X 1050 = 92,400 Btuh In this example, the orifice size and manifold pressure adjustment is within ±2 percent of the furnace input rate.

d. To change blower motor speed selections for heating

mode, remove blower motor lead from control board HEAT terminal. (See Fig. 14.) Select desired blower motor speed lead from 1 of the other terminals and relocate it to HEAT terminal. See Table 10 for lead color identification. Reconnect original lead on SPARE terminal.

Follow this same procedure for proper selection of COOL speed selection.

TABLE 9—GAS RATE (CU FT/HR)

SECONDS

FOR 1

REVOLUTION

SIZE OF TEST DIAL

10 360 720 1800 50 72 144 360 11 327 655 1636 51 71 141 355 12 300 600 1500 52 69 138 346 13 277 555 1385 53 68 136 340 14 257 514 1286 54 67 133 333 15 240 480 1200 55 65 131 327 16 225 450 1125 56 64 129 321 17 212 424 1059 57 63 126 316 18 200 400 1000 58 62 124 310 19 189 379 947 59 61 122 305 20 180 360 900 60 60 120 300 21 171 343 857 62 58 116 290 22 164 327 818 64 56 112 281 23 157 313 783 66 54 109 273 24 150 300 750 68 53 106 265 25 144 288 720 70 51 103 257 26 138 277 692 72 50 100 250 27 133 267 667 74 48 97 243 28 129 257 643 76 47 95 237 29 124 248 621 78 46 92 231 30 120 240 600 80 45 90 225 31 116 232 581 82 44 88 220 32 113 225 563 84 43 86 214 33 109 218 545 86 42 84 209 34 106 212 529 88 41 82 205 35 103 206 514 90 40 80 200 36 100 200 500 92 39 78 196 37 97 195 486 94 38 76 192 38 95 189 474 96 38 75 188 39 92 185 462 98 37 74 184 40 90 180 450 100 36 72 180 41 88 176 439 102 35 71 178 42 86 172 429 104 35 69 173 43 84 167 419 106 34 68 170 44 82 164 409 108 33 67 167 45 80 160 400 110 33 65 164 46 78 157 391 112 32 64 161 47 76 153 383 116 31 62 155 48 75 150 375 120 30 60 150 49 73 147 367

Cu Ft2Cu Ft5Cu Ft

SECONDS

FOR 1

REVOLUTION

SIZE OF TEST DIAL

Cu Ft2Cu Ft5Cu Ft

2. Set temperature rise. Furnace must operate within range of temperature rise specified on the unit rating plate. Determine the air temperature rise as follows.

a. Place duct thermometers in return and supply ducts as

near furnace as possible. Be sure thermometers do not “see” heat exchangers so that radiant heat will not affect thermometer readings. This is particularly important with straight-run ducts.

b. When thermometer readings stabilize, subtract return-air

temperature from supply-air temperature to determine temperature rise.

c. Adjust air temperature rise by adjusting blower speed.

Increase blower speed to reduce temperature rise. Decrease blower speed to increase temperature rise.

WARNING: Disconnect the electrical power before changing the speed tap. A failure to follow this warning could result in personal injury.

CAUTION: If Model 376CAV066115 is installed in

0.50-in. wc or lower static pressure ductwork, evaporator coil condensate blow off can occur during cooling operation. When installed in this manner, do not use high blower speed tap for cooling.

TABLE 10—SPEED SELECTOR

COLOR SPEED

Black High COOL

Yellow (When Present) Medium-High SPARE

Blue Medium-Low HEAT

Red Low SPARE

White Common L2/COM

FACTORY-

ATTACHED TO

CAUTION: Recheck temperature rise. It must be within

limits specified on unit rating plate. Recommended operation is at midpoint of rise or above.

3. Set thermostat heat anticipator. The thermostat heat anticipator must be set to match the amp draw of the electrical components in the R-W circuit. Accurate amp draw readings can be obtained at thermostat subbase terminals R and W. Fig. 19 illustrates an easy method of obtaining the actual amp draw. The amp reading should be taken after the blower motor has started. See the thermostat manufacturer’s instructions for adjusting the heat anticipator and for varying the heating cycle length.

NOTE: When using an electronic thermostat, set cycle rate for 3 cycles per hr.

V. CHECK SAFETY CONTROLS

The flame sensor, gas valve, and pressure switch were all checked in the Start-Up Procedures section as part of normal operation.

1. Check primary limit control. This control shuts off the combustion control system and energizes the circulating-air blower motor if the furnace overheats. The preferred method of checking the limit control is to gradually block off the return air after the furnace has been operating for a period of at least 5 minutes. As soon as the limit has shut off the burners, the return-air opening should be unblocked. By using this method to check the limit control, it can be established that the limit is functioning properly and operates if there is a motor failure.

2. Check blocked vent safeguard switch. The purpose of this control is to permit the safe shutdown of the furnace during certain blocked vent conditions.

a. Disconnect power to furnace and remove vent connector

from furnace outlet collar. Be sure to allow time for vent pipe to cool down before removing.

—19—

THERMOSTAT SUBBASE TERMINALS WITH THERMOSTAT REMOVED (ANITICIPATOR, CLOCK, ETC., MUST BE OUT OF CIRCUIT.)

HOOK-AROUND AMMETER

R Y W G

10 TURNS

FROM UNIT 24-V CONTROL TERMINALS

EXAMPLE:

5.0 AMPS ON AMMETER 10 TURNS AROUND JAWS

0.5 AMPS FOR THERMOSTAT

ANTICIPATOR SETTING

Fig. 19—Amp Draw Check With Ammeter

b. Restore power to furnace and set room thermostat above

room temperature.

c. After normal start-up, allow furnace to operate for 2

minutes, then block flue outlet 100 percent. Furnace should cycle off within 2 minutes.

d. Remove blockage and reconnect vent pipe to furnace

outlet collar.

e. Wait 5 minutes and then reset blocked vent safeguard

switch.

3. Check pressure switch. This control proves operation of draft inducer blower.

a. Turn off 115-v power to furnace. b. Remove control door and disconnect inducer motor lead

wires from wire harness.

c. Turn on 115-v power to furnace.

A96316

d. Set thermostat to “call for heat” and wait 1 minute.

When pressure switch is functioning properly, hot surface igniter should NOT glow and control diagnostic light flashes a status code 31. If hot surface igniter glows when inducer motor is disconnected, shut down furnace immediately. Determine reason pressure switch did not

function properly and correct condition. e. Turn off 115-v power to furnace. f. Reconnect inducer motor wires, replace control door, and

turn on 115-v power.

4. Check auxiliary limits (when used). a. Turn off 115-v power to furnace. b. Remove blower access door. c. Disconnect red motor lead at blower speed selector.

Mark terminal for proper re-connection. d. Replace blower access door. e. Turn on 115-v power to furnace. Be sure room thermo-

stat is calling for heat. f. Allow furnace to operate until auxiliary limit activates,

but DO NOT operate furnace longer than 4 minutes.

g. If furnace operates for 4 minutes, check/replace limit

switch(es). h. Turn off 115-v power to furnace. i. Remove blower access door. j. Reconnect red motor lead, reset switch, and replace door. k. Turn on 115-v power to furnace

VI. CHECKLIST

1. Put away tools and instruments and clean up debris.

2. Verify manual reset switches has continuity.

3. Ensure blower and control access doors are properly installed.

4. Cycle test furnace with room thermostat.

5. Check operation of accessories per manufacturer’s instructions.

6. Review User’s Guide with owner.

7. Leave literature packet near furnace.

—20—

CHECKLIST—INSTALLATION

LOAD CALCULATION

_________________ Heating Load (Btuh) _________________ Cooling Load (Btuh) _________________ Furnace Model Selection

AIR FOR COMBUSTION AND VENTILATION

_________________ Unconfined Space _________________ Confined Space

VENTING

_________________ NFGC (United States) _________________ NSCNGPIC (Canada) _________________ Local Codes _________________ 1/4-in. Upward Slope _________________ Joints Secure _________________ See Vent Table Instructions

CHECKLIST—START-UP

_________________ _________________ Temperature Rise Adjusted

_________________ Thermostat Anticipator Setting or _________________ Thermostat Cycle Rate (3 cycles per Hr)

_________________ Primary Limit _________________ Pressure Switches _________________ Draft Safeguard Switch _________________ Auxiliary Limit Switch(es)

_________________ Manufacturer _________________ Model number

(Set Within 2 percent of Rating Plate)

CHECK SAFETY CONTROLS OPERATION

Gas Input Rate

Thermostat

—21—

—22—

—23—

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.

Classroom Service Training plus "hands-on" the products in our labs can mean increased confidence that really pays dividends in faster troubleshooting, fewer callbacks. Course descriptions and schedules are in our catalog.

CALL FOR FREE CATALOG 1-800-962-9212

[ ] Packaged Service Training [ ] Classroom Service Training

—24—

Printed in U.S.A. 376c503 Catalog No. 5337–605

Bryant 376CAV Installation Instruction

Specifications and Main Features

Frequently Asked Questions

User Manual