Carrier 58BB User Manual

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Page 1

Carrier

Installation, Start-Up

and Service Instructions

Downflow Gas-Fired Furnaces

INTRODUCTION

The design of the 58BB,BD Downflow GasFired Furnaces is A.G.A. certified for close clear ance, “hide-a-way” installation. These units meet requirements for under-the-house warm air delivery for either concrete slab or crawl space construc

tion. See Fig. 1 and Table 1 for furnace dimensions and physical data. See Table 2 for blower data.

Table 1 — Dimensions and Physical Data

58ВВ,В

FURNACE 58 MODEL SERIES^ APPROX SHIP. WT (lb) DIMENSIONSlin.)

Width A Length B Height C

With Plenum D

Supply Air Opening E

Return Air Open Front to Vent Cl H

Front to Conn. Cl J

Vent Diom K Min Floor Opening L

Input (1000 Btuh) Bonn Cop. (1000 Btuh) T emp

Series 100,400

Rise

Series 200,500

(F)** ESP’

Series 100,400

(in.

Series 200,500

wg)

FILTERStt No.

Size (in.)

080 100 120

100^200,400,500

16У4

20У4

18Ув

"ТаУв'"

']4% ^

18%

^2%

2% ”

01::

]4%

Natural or

100

70-100

120 ^9¿-

'64

' 45-Ю0

,12|.15 [.20

:50' '

16x16x1

080 100 125 150

200,500

, J54„

16У4

56 V

^ 14%"

i'Jl

14У4

’ropane (3as

100

'so'

45-100

16x18x1

208 244

20У4 24У4

-- -28 ' ¿0*

18%

22%

18%

22%

18% "

18%

22%“

125

150

loó

18>

floor

OPENING

ESP — External Static Pressure

*Add 1-1/4 in when installed on combustible flooring with non

combustible base

fAdd 18 1/2 in. when installed with 28AE900051 cooling coil

plenum; 22 1/2 in when installed with 28AE900061 plenum (series 200 and 500 units only)

t Ratings shown for elevations up to 2000 ft For elevations above

2000 ft, deduct 4% of input capacity for each 1000 ft above sea

level

**Air temp rise may be calculated using the following formula:

At =

0 24 X specific wt of air x 60 x cfm

bonnet capacity

tf58BB units use throwaway filters; 58BD units use permanent

cleanable filters

(s) (?) Сягг!яг Piirnnratinn 1Q79

______

1 08 x cfm

bonnet capacity_____________

AIR FLOW

¡SERVICE aEARANCE

58BB,BD

NOTE; Aiiow safety ciesrance of 1 in. from sdes, top, and

type B vent; 6 in. from unlisted vent; 1 in. at rear.

Fig. 1 — Dimensions

Furnaces may be matched with certain 28 Series cooling coils to form combination heating/ cooling systems (see Table 3) and employed with humidifiers and electronic air cleaners to form complete controlled-environment systems.

. COD D D ГЛ OO I

Page 2

Table 2 — Blower Data

BLOWER FURNACE 58 SERIES MOTOR

Nom Size (in.) Hp

PPD BL BMPS* ESP (in. wg)t Air Delivery (max cfm)1

BL — Belt Length BMPS — Blower Motor Pulley Setting (turns open from closed position) ESP — External Static Pressure PPD — Pulley Pitch Diameter (range 2.1 — 2 9 in )

100,400

.20

730"

080

9x8

„.30

650

BB DIRECT DRIVE

200,500 100,400

J0x8

.20

1100501020

890'

9x8

100 120

200,500 100,400

J0x8

.20

1180

.50

1080

1070

*Do not close blower motor pulley beyond setting shown fFilter in place :fWith motor set at "High" speed NOTE; Referto Application Data literature for fan performance curves.

_^0

760

9xj0

.30

920

200,500

jo>i!0

.50

.20

1250

1200

080,100

10x8

"36"

.20

980 1120

BD BELT DRIVE

200,500

12x9

^ Al

.20 .50

.50

260 1380

125 150

J2xU

^ 1

" "41 ‘

_4_

.20

1620 1800

J„„

.50

Table 3 — Furnace-Coil-Plenum Combinations

FURNACE

58BB080, 58BB100, 58BB120

58BD080, 58BD100

58BD125

58BD150

NOTE; Adapters not required.

28AF002 28AE,AF003 28AE,AF004

28AE,AF003 28AE,AF004 28AE,AF005

28AE,AF005 28AE006

COIL

PLENUM

28AE900051

28AE900061

Series 100 and 200 units are tested and approved for use with natural gas. Series 400 and 500 are factory built and approved for use with

100% propane gas. Firing of these units with any

other gas or mixture is not approved.

Furnaces are shipped fully assembled, including built-in draft diverters. Heating/cooling models are equipped with a printed circuit control center, which provides a central control connection point for furnace components and field-added acces sories. All internal electric and gas controls are factory assembled and wired.

When unpacking unit, should any in-transit damage be observed, file claim with transportation agency.

This publication covers furnace and non

combustible base installation. It also shows ter minal connections used for wiring accessories to furnace. For accessory installation details, refer to

applicable installation literature.

INSTALLATION

Location Selection

When selecting a location for the furnace,

observe the following:

1. Install furnace close to chimney and as central ized as possible with respect to distribution system.

2. Locate cooling coil (if used) downstream from furnace.

3. Ensure adequate door clearance for service access.

4. Ensure adequate ventilation. (See Combustion Air.)

5. Follow local and national utility codes.

a. Allow safety clearance of 1 in. from sides,

top and type B vent; 6 in. from unlisted

vent; 0 in. at rear.

b. Provide service clearance of 30 in. at front

of unit.

c. Downflow furnaces are not approved for

installation directly on combustible floors.

Unless furnace is set on a concrete slab floor, use of a noncombustible base is required. (See Fig. 2.) Noncombustible base

is available as an accessory package. If

furnace is combined with a cooling coil, plenum can serve as the noncombustible base.

d. If furnace is to be installed on the first floor

of a house built over a crawl space, make sure that unit and noncombustible base (if required) will rest on supported floor joists. Otherwise, vibrations could be set up, result ing in unnecessary and undesirable noises.

e. Make sure that a positive air seal is made on

all four sides of the furnace.

Page 3

Fig. 2 — Installation of Noncombustible Base On

Combustible Flooring

f. If cooling coil is to be used with furnace,

provision should be made downstream of the coil to collect and drain any condensate that may blow off the coil.

^ g. Consult NFPA No. 54; Installation of Gas

Appliances Gas Piping 1969.

Installation Procedures

Install ductwork, filters, and vents; complete

external piping and wiring; and provide for com

bustion and recirculating air.

Fig. 3 - Installation of Filters in Return Air Duct

Page 4

DUCTWORK RECOMMENDATIONS

1. Install locking-type dampers in all branch or individual ducts to balance out system.

2. Use tapered fittings or starter collars between ducts and plenum.

3. Use flexible duct connection (asbestos cloth)

between furnace and discharge plenum.

4. Install acoustical insulation in warm air plenum;

install sound traps in short run ducts.

5. Run return air connections under floor or I'un full size return from space outside enclosed

area. If outdoor air is used, combination of

outdoor and return air requires duct design and diverting dampers so installed that volume of

circulating air entering furnace cannot be re

duced or restricted below that which would normally enter thru circulating air intake of

furnace

Table 4 — Pipe Sizing*, Capacity For Natural Gas,

Cu Ft/Hr

PIPE SIZE

132 92 73 63 56 50

’4

U/4

*Based on pressure drop of 0 3 in. wg, 0 6 sp gr gas fWithout elbows

NOTE: For pipe sizing capacity for LP gases, refer to NFPA No. 54

278 520

1050 730 590

X — J

PIPE

LENGTH (ft)t

20 30 40

190

152 130

350 285 245

500

___

115 105 96 90 215 195 180 170 440 400 370

_-,J

vent outlet terminates in an approved cap with

a venting capacity not less than that of the

vent. (See Table 1 for vent sizes.)

350

FILTERS — Filters are shipped from factory in blower compartment of furnace. (See Fig. 3.) To gain access, remove top front panel and filter

compartment doors located at right- and left-hand sides of vent. Install by raising filters above rightand left-hand side of blower and positioning on

filter rack as shown in Fig. 3. As an aid in filter removal, an access panel could be field fabricated in the front of the return air supply plenum.

VENTS — Vent furnace to permanent chimney or thru roof with vent of approved design. (Type B vent is recommended.) Observe local ordinances.

1. Size flue pipe connections same as furnace vent connection. (See Fig. 1 and Table 1.)

2. Run pipe as directly as possible with minimum number of turns.

3. Maintain minimum pitch of 1/4 in. per linear ft on horizontal runs. Pitch should not exceed 75% of vertical vent.

4. Maintain minimum angle of 60 degrees from vertical for vent pipe crossovers in attic.

5. Rigidly support pipe with hangers or straps.

6. Do not connect into a chimney serving an

open fireplace.

7. If chimney is used, total equivalent straight

length of flue piping between furnace and flue pipe connection at chimney must not be greater than 75% of vertical height of chimney above flue pipe connection.

8. Install flue pipe to extend thru chimney wall but not beyond inside wall of flue.

9. Minimum vertical stack height is 5 ft. Extend flue pipe at least 3 ft above roof and 2 ft above any object within a 15-ft radius. Ensure that

10. Insulate flue pipe where it passes near com bustible material. Underwriter’s Laboratories

(UL) require that uninsulated flue pipe be installed with a minimum clearance of 6 in. from combustible materials. Vent piping,

which meets with National Board of Fire Underwriter’s Specifications for type B vents, may be installed with a clearance of 1 in. from

combustible materials.

If other gas appliances are vented into

common flue, flue area must equal largest vent area

plus one-half total areas of other vent conneetors.

GAS PIPING — Install piping per national and local

codes, and NFPA No. 54.

1. Furnish gas line from main gas supply to

furnace.

2. Size supply pipe per volume of gas used and allowable pressure drop. (See Table 4.) Supply

pipe size must at least equal that of furnace gas connection.

■ 3. Refer to NFPA No. 54 for additional suggested

methods of piping.

a. Install drop pipe adjacent to, but not in

front of furnace.

b. Install manual shutoff valve on gas piping

per local codes.

c. Install tee in pipe at same elevation as gas

inlet connection to unit; provide ground

joint union between tee and furnace

controls. d. Extend drip leg and cap it. e. Test for pressure and leaks.

CAUTION: Never rise open flame for testjxig.

Page 5

WIRING — Fig. 4 shows the printed circuit control

center, which is factory-installed on heating/ cooling furnaces. Fig. 5 illustrates the field power

LOW VOLTAGE TERMINAL STRIP

40-VA TRANSFORMER

(STANDARD

COMPONENT)

and control wiring for heating only furnaces; Fig. 6

illustrates the field power and control wiring for the heating/coohng models.

When wiring units, make sure that all national and local codes are followed. Check against loose wiring connections.

HUMIDIFIER RELAY

RECEPTACLE (SEE NOTE 2)

PLUG-IN BLOWER RELAY (STANDARD

COMPONENT)

When making aluminum conductor connections to copper conductors or terminals, use only con nectors which are UL approved for the application. (UL approved connectors will be tin plated, have separator bars for placement between conductors to prevent direct contact between aluminum and copper, and have large bearing surfaces to minimize unit pressures for minimum cold flowing of the aluminum and subsequent loosening of the joint.)

LINE VOLTAGE CONNECTIONS

After insulation has been stripped from alumi

num conductor, coat conductor end with corrosion

inhibitor (Burndy “Penetrox A” or equivalent),

and wire brush aluminum surface thru inhibitor.

After cleaning, recoat aluminum conductor with inliibitor, and make up connection. (Coat entire connection.)

If applicable, wrap connection for moisture

andjor electrical protection.

Field Power Wiring — (See Fig. 5 and Fig. 6.)

NOTES: 1 All factory-wired connections are !4~in quick-connect terminals:

all field-connection points are screw terminals.

2 Optional component, humidifier relay, is plugged into receptacle

HR when low voltage humidifier is added to system.

Fig. 4 — Printed Circuit Control Center,

Cover Removed

Heating Only Models

1. Connect separate 115-volt, single-phase, 60-Hz

power supply thru hole in side of unit casing to

115-volt pigtails.

2. If required by local codes, install fuse and manual switch between main box and furnace.

Heating/Cooling Models (With Printed Circuit Control Center)

1. Connect separate 115-volt, single-phase, 60-Hz power supply to terminals Lj and L2 on the printed circuit control center. (See Fig. 4.)

2. If required by local codes, install fuse and manual switch between main box and furnace.

3. When adding an electronic air cleaner to the system, connect air cleaner to terminals EACi and EAC2. These terminals supply 115-volt power to the electronic unit.

4. When adding a line-voltage humidifier to the system, connect humidifier to terminals HUi and HU2.

Humidifier has its own control wiring, which is independent of the furnace, except for the power connections provided at HUj and HU2-

5. When replacing a single-speed motor with a dual-speed motor, be sure to remove jumper between HI and LO on the control center.

Field Control Wiring — (See Fig. 5 and Fig. 6.) Heating Only Models

1. Connect two 24-volt leads from accessory thermostat to low-voltage pigtails R and W.

2. For constant fan operation, turn summer switch, located on the furnace junction box, to the “On” position.

Heating/Cooling Models (With Printed Circuit Control Center)

1. For heating with constant fan control, connect leads from room thermostat subbase to ter minals W, G, and R on the low voltage terminal strip. (See Fig. 4.) This hook-up is

used when heating only with manual fan control at the thermostat is desired.

2. Connect accessory thermostat to furnace and cooling unit. Connect terminals W, G, R and Y on the thermostat subbase to identically labeled terminals on the low voltage terminal strip. Connect yellow and black low voltage leads from the remote condensing unit to the two C terminals on the low voltage terminal strip.

Page 6

3. When adding a low voltage humidifier to the system, install a plug-in humidifier relay in receptacle HR on the control center. Connect humidifier directly to terminals H and H on the low voltage terminal strip. Connect leads from low voltage humidistat, in the conditioned space, to terminals HS and HS on the low voltage terminal strip.

IMPORTANT; Set adju.stabie heat antic ipator (if provided) to agree with ampere value of combination ga.s vaive. Failure to make adjxisiment will result in unsatisfac tory temperature control.

VALVE

Essex XA^lpho'Taico) T;F 555 ünîftoi 700Û

|heat ANTSOPATOR

\ SETTWÇ i • 0.4So

1 G.20o

^ COMBUSTION AIR ^ See NFPA No. 54.

1. If furnace is installed in a confined area, such as a closet or utility room, provide air for combustion.

a. Provide two air openings to interior space of

equal area, one located near the top of the enclosure and one at the bottom.

b. Make sure that openings have free area not

less than lOOsqin. in area, plus an addi tional 1 sq in. for each 1000 Btuh in excess of 100,000 Btuh input.

c. Where openings to interior spaces are im

practical, follow the methods outlined in NFPA No. 54.

2. If furnace is installed in an unconfined area, such as in a full basement, it can normally be assumed that infiltration will provide sufficient air in building of conventional frame, brick or stone construction. In buildings of unusually tight construction, provide a permanent open ing to the outdoors with a minimum free area of not less then 1 sq in. per 4000 Btuh total input ratings of all appliances in space.

3. Consult local codes for special requirements. CAUTION: Whenever gas appliance is installed

in any area where corrosive atmosphere or chlorine or chlorinated compounds are present, bring combustion air into combustion area of furnace from outdoor source. Failure to do this can cause excessive corrosion in furnace heat exchanger.

CIRCULATING AIR SUPPLY

Consult local

ordinances and NFPA No. 54.

1. Do not take circulating air from same space as combustion air Supply may be any mixture of outdoor and return air with minimum tempera ture of 50 F.

LEGEND (Common for Fig. 5 and Fig. 6)

___ Field Power Wiring (115 Volt)

. Factory Power Wiring (115 Volt)

— Printed Circuit Control Center Wiring (11 5 Volt)

----------Field Control Wiring (24 Volt)

---------- Factory Control Wiring (24 Volt) —.— Printed Circuit Control Center Wiring (24 Volt)

Screw Terminal — Field-Connection Points (115 Volt and

24 Volt) ’4-in Quick-ConnectTerminal - Factory-Wired Connections

(115 Volt and 24 Volt)

NOTES; 1 To change tow speed, pull out speed selector plug and plug in with

desired speed marking facing away from motor shaft.

2 To change motor speed, move red lead to desired terminal on

motor

CAUTION: Do not move w/iire wire. Do iwt operate or>

"High" speed unless cooiiog coii ie used.

3 Wire ¿itocA: 58BD motor leads as indicated forwhiteand red 58BB

motor leads 4 Knockout provided for field installation 5 Total electrical load is less than 1 2 amps

6 Whenever replacing original wire supplied with furnace, use

AWM (90 C with 3/64-in thick insulation for 24-volt and 4/64-in thick insulation for 115-volt) wire or its equivalent

7 Motor(s) furnished with thermal overload protection

Fig. 5 — 58BB.BD Field Power and Control Wiring,

Heating Only Diagram

2. Install ducts and diverting dampers so that

volume of circulating air entering furnace is unrestricted.

3. Bring return air connection thru top of furnace.

Where there is no complete return duct system, run return air duct full size to location outside

enclosed area. Return air plenum must extend a

sufficient height above 14 in. required for filter

removal to provide for attachment of return air duct or grille.

Page 7

VALVE

(SEE NOTE 5 )

SLO'WER MOTOR

LOjS

TERMINAL JUMPER

Refer to Fig 5 for legend and notes

8R I 8R„

blower; Slower

RELAY I RELAY

--------------------------------------------

58BD WIRING

115-VOLT

POWER SUPPLY '

FIELD-ADDED LINE VOLTAGE HUMIDISTAT AND HUMIDIFIER

¡•EHZ]-

HUo HU

----------------------------------------------

' rnu WWW ' (HUMID RELAY ! ^ ^ I

COM . FIELD ADDED) I F2 F| .

1—'0}~-*ll*—§—1

I vs. « FAW I

FAN

SWITCH

SWITCH ,

--------------------

■^FIELD-ADDED ELECTRONIC AIR CLEANER

—lU-

------------------

‘■‘pR,

SEC I

"TlÈLD^bDÉD'n

PLOW VC

rL-, HUM

vaIve valve

V'»—0—0w

--------------CDs

VOLTAGE I

HUMIDIFIER j

-------

--------

_________

((FIELD-ADDED i HUMIDIFIER RELAY)

■ LIMIT

-----

(«HH»

---------

HR HS .'T

----------

^~~vOQQ .T"*^

SEC£j

FIELD-ADDED LOW

^VOLTAGE HUMIDISTAT

-------------

----

-(^ ^

LIMIT

58BB SCHEMATIC

AUX LIMIT

(IF USED) —•=№•—

(CONTACTOR IN

REMOTE CONDENSING UNIT)

1 115 VOLT (

-J 24 VOLT ^

l^jHS H .

---------TRANS

-----------

PILOT

BLOV

(BLOWER RELAY)

115-VOLT

I POWER SUPPLY

'Ll

4),

Fig. 6 — 58BB,BD Field Power and Control Wiring, Heating/Cooling With Accessories Diagrams

Page 8

START-UP AND SERVICE

IMPORTANT; Remove shippmg pad from

motor moiintkig angle before operating blower.

Initial Start-Up

When first lighting furnace pilot:

1. Open all warm air registers.

2. Set room thermostat to lowest setting.

3. If humidifier is installed with system, open water supply valve.

4. If line voltage switch is provided in furnace circuit, turn it to “Off” position.

5. Turn gas cock dial (see Fig. 7 and Fig. 8) to “Off” position.

6. Wait approximately 5 minutes to allow gas wliich may have accumulated in burner com

partment to escape.

7. Turn gas cock dial to “Pilot” position.

8. On Unitrol 7000 valves, depress and hold gas

cock dial while lighting pilot burner. If valve is equipped for 100% shutoff, allow pilot to burn approximately one-half minute before releasing dial (Unitrol 7000 valve) or before depressing automatic pilot reset button (Essex TF 555 valve). If pilot does not remain lighted,

repeat operation allowing longer period before

releasing dial or depressing button. If neces

sary, adjust pilot. (See Pilot Burner

Adjustment.)

9. Turn gas cock dial to “On” position.

10. Set room thermostat at desired temperature position.

IMPORTANT; For the Unitroi 7000 models

equipped with a pressure regulator, do not

adjust gas input between “Pilot” and “On” positions on the gas cock dial.

Pilot Burner Adjustment

Remove pilot adjustment cap. (See Fig. 7.)

Adjust pilot key to provide properly sized

flame. (Ignition flame should extend outward and upward approximately 1.5 in. from the stem of the pilot.) Turn screw clockwise for high flame or counterclockwise for low flame.

Replace pilot adjustment cap.

Combustion Air Adjustment

Primary air shutters are provided on all furnaces

to enable adjustment of the primary air supply to get proper flame characteristics. Adjust the air shutters as follows;

1. After furnace has been operating for 15 minutes, loosen air shutter screw on each burner face.

Close air shutter until yellow tips appear in

flame. Then, open air shutter until yellow tips disappear and flame has soft blue cone.

Secure air shutters in position by tightening each air shutter screw.

Blower Speed Adjustment

Adjust on installation for nameplate tempera

ture rise. (See Table 1.)

1. For direct drive speed change (58BB furnaces), perform the following;

a. Rotate speed-change plug or move line lead

from fan switch to desired speed terminal.

When plug is rotated, desired speed marking

should face away from motor shaft.

Speeds on plug are marked. High (•), Medium-High (••), Medium-Low (•••), and Low (••••)

b. For speed selection on direct drive model

with terminal connections, change terminal

at motor. (See Fig. 5 and Fig. 6.)

GAS COCK DIAL

PILOT CONNECTION

REGULATOR ADJUSTMENT SCREW CAP

ESSEX TF 555

(Used on 58BB Furnaces)

•"Available only on valves equipped for 100% shutoff.

GAS COCK DIAL

OUTLET (NOT VISIBLE)

AUTOMATIC PILOT RESET BUTTON*

PRESSURE TAP (NOT VISIBLE)

PILOT ADJUSTMENT CAP

VENT

PILOT CONNECTION

PILOT

ADJUSTMENT

CAP

thermocouple

CONNECTION

Fig. 7 — Combination Gas Valves

UNITROL 7000

(Used on 58BD Furnaces)

VENT

(NOT VISIBLE)

REGULATOR ADJUSTMENT SCREW CAP

-outlet

(NOT VISIBLE)

PRESSURE TAP

(NOT VISIBLE)

Page 9

1 •>

58BB NATURAL GAS BURNERS

WITH ESSEX TF 555 GAS VALVE

58BD NATURAL GAS BURNERS

WITH UNITROL 7000 GAS VALVE

58BB PROPANE GAS BURNERS

WITH ESSEX TF 555 GAS VALVE

Fig. 8 — 58BB,BD Gas Burners and Manifold Assemblies

2. For belt drive speed change (58BD furnaces), perform the following;

a. Loosen setscrew on adjustable hub of motor

sheave.

b. Rotate hub clockwise to increase or

counterclockwise to decrease speed and tighten setscrew on flat hub section.

Belt Adjustment

Adjustment is correct if one-finger pressure

depresses center of belt 1 inch. Each blower speed

change on a 58BD furnace requires a belt

adjustment.

1. Loosen locknut.

2. Turn adjusting screw on motor mounting bracket in to tighten or out to loosen.

3. Tighten locknut.

58BD PROPANE GAS BURNERS WITH UNITROL 7000 GAS VALVE

Fan and Limit Control

1. Constant air circulation provides even temper: ture control. The lower the fan switch settin; the longer the fan will continue to run afti burners turn off.

2. After running furnace for 15 minutes, restri^ the return air supply by blocking the filters ( by closing the return registers.

3. Allow furnace to shut down on high hmit. F: must continue to run.

4. Remove restriction. Burners should come on a few minutes.

5. Adjust “Off” setting per installation needs.

“On” setting is 25 F above “Off” settii

differential is not adjustable.

Page 10

Input Adjustment

1. Turn off all other gas appliances on same meter.

2. Set thermostat high enough to ignite burners.

3. Check cu ft of gas burned per minute. Multiply value by 60 minutes to determine input (in thousands of Btuh). Rating should be within

5% of nameplate input rating.

4. To adjust input, remove combination gas valve

cap covering regulator adjusting screw. (See Fig. 7.)

TROUBLESHOOTING

5. With a small screwdriver, rotate adjustment screw clockwise to increase or counterclockwise to decrease pressure. Do not change pressure more than ± 0.3 in. wg.

6. Replace regulator adjustment screw cap. IMPORTANT; Refer to operating and main-

tenance instruction Eterature to ensure better, longer, and more reEable service from your new Carrier furnace.

Burner Will Not Operate

POWER FAILURE — Power switch off — set to on, blown fuse — replace, defective wiring — replace

NO POWER TO CONTROLS - Thermostat set too low, dirty or defective — reset, clean or replace as

applicable; defective transformer — replace; faulty

limit switch — replace; blown fusestat ~ replace

BURNER WILL NOT IGNITE ^ Low gas pressure or no gas to unit — check if manual shutoff valve is

closed, check gas supply, check for clogged gas line and clean or repair, adjust gas pressure with all appliances operating; faulty thermocouple — check

with millivoltmeter and replace if necessary; pilot

light extinguished — locate cause and relight, dirty

pilot — clean

Burner Operates, But Heating Inadequate

UNIT UNDERSIZED — Size selected incorrectly —

never overfire, replace with properly sized unit

FUEL INPUT TOO LOW — Wrong orifice size —

replace orifice; regulator set too low — readjust. THERMOSTAT OPENS TOO SOON - Wrong

anticipator setting ~ readjust; thermostat out of

cahbration — recalibrate; thermostat set wrong — check and reset as necessary; wrong thermostat location — relocate.

LIMIT SWITCH CYCLES BURNER - Dirty filters

-- clean or replace, faulty fan switch or motor —

repair or replace; blower speed too low — readjust;

fan switch set too high — readjust; duct system

restricted — remove restriction.

Poor Combustion and Flame Characteristics

SMOKY FLAME — Insufficient air — adjust air inlet; flue restriction — remove restriction; down- draft — eliminate downdraft using flue caps on vents

NOISY BURNER — Too much air — adjust air

inlet, incorrect input — make correction as required

Page 11

For replacement items use Carrier Specified Parts.

Manufacturer reserves the right to change any product specifications without notice.

CARRIER AIR CONDITIONING COMRANY • SYRACUSE, NEW YORK

Tab 10 Form 58BB.BD-3SI Supersedes 58BB,BD-2SI Printed in U S A. 10-72 Codes E and MS Catalog No 535-828