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b. Check all wiring between the ignitor control and the gas

valve. Check to make sure the ground connections are
intact.

c. If the wiring is intact, check for 24 volts across terminals

“PV” and “COMMON” on the ignitor control. If 24 volts
is not present, replace the ignitor control.

d. If 24 volts is present, remove the pilot burner and

remove the pilot orifice from the pilot burner. The orifice
is removed in the direction opposite the flow of gas.
Inspect the orifice for obstruction. If it is clear, replace
the main gas valve.

5. The sparker sparks at the pilot burner but the pilot does not

ignite and a gas odor is detected at the draft motor outlet.

a. Adjust the pilot adjust screw on the gas valve as

described in “PILOT CHECKOUT”.

b. Check the supply pressure as described in “POST

START CHECK LIST”. Make adjustments as necessary.

c. Check the pilot orifice for obstruction as described in

Item 4. Clean as needed but the problem should not be
the gas valve.

6. The pilot burner ignites but the sparker continues to spark

and the main burners do not ignite.

a. Make the same checks and adjustment as described in

Item 5.

 b.Make sure that the pilot burner is not bent or damaged.

c. Make sure that the ground connections at the pilot

burner, gas valve and ignitor control are intact. Check
the high tension wire for good electrical connection. If
all are intact, replace the ignitor module.

7. The pilot burner lights and the spark stops but the main

burners do not light.

a. Check electrical connections between the ignitor con-

trol and the gas valve. If intact, check for 24 volts across
terminals “MV” and “COMMON” terminals. If no voltage
detected, replace ignitor control. If voltage is present,
replace gas valve.

8. Furnace lights with roll out or one burner has delayed

ignition.

a. Make sure that the pilot burner is aligned properly with

the carryover as described in “PILOT CHECKOUT”.

b. Make sure that the carryovers on adjoining burners are

screwed fast and are level with respect to one another.

9. Main burners light but exhibit erratic flame characteristics.

a. Adjust air shutters as described in “BURNER AIR

SHUTTER  ADJUSTMENT”.

b. Check the main burner orifices for obstruction and

alignment. Removal procedure is described in
“BURNER INSTRUCTIONS”. Clean or replace burner
orifices and burners as needed.

REPLACEMENT PARTS

COMPRESSOR SECTION

Hermetic compressor

Compressor mounting

MOTOR SECTION

Blower motor

Fan motor

Ventor motor

ELECTRICAL SECTION

Ignition control

Relay board

Contactor

Circuit breaker

Temperature controls

Capacitors

Relays

Transformers

Connectors

GAS HEAT SECTION

Heat exchanger

Gas valve

Pilot

Flame sensor

Spark ignitor

Gas manifold

Gas burner

AIR MOVING SECTION

Blower wheel

Blower wheel housing

REFRIGERANT SECTION

Evaporator coil

Evaporator coil header

Expansion valve assembly

Condenser coil

Condenser coil header

FABRICATED PARTS SECTION

Panels

Posts

Covers Drain pans

Base rails

Air hoods

MISCELLANEOUS SECTION

Air inlet hood screen

Fan guard

Air filters

TO OBTAIN PARTS INFORMATION: Replacement parts and information from OUR current parts list for this unit are available to
your servicing contractor through our local distributor. The name and address of our nearest distributor may be obtained by
consulting the Yellow Pages of a local telephone directory.
IMPORTANT: In order to supply the correct part or information from the parts list, our distributor will need to be provided with the
complete model number listed on the rating plate located on your unit. See page 2 for Product Nomenclature.
WARNING: IMPROPER INSTALLATION, ADJUSTMENT, SERVICE OR MAINTENANCE CAN CAUSE INJURY OR PROPERTY
DAMAGE. CONSULT A QUALIFIED INSTALLER, SERVICE AGENCY OR YOUR LOCAL GAS SUPPLIER FOR INFORMATION
OR ASSISTANCE.

530.18-N10Y

Unitary Products Group

19

Summary of Contents for D3CG090

Page 1: ...ting of replacement parts on this equipment All forms referenced in this instruction may be ordered from Publications Distribution Center Unitary Products Group P O Box 1592 York Pa 17405 APPROVALS De...

Page 2: ...ication Data 3 2 Gas Heat Application Data 5 3 Pipe Sizing 5 4 Physical Data 8 5 Supply Air Blower Perf 7 1 2 10 Ton 10 6 Supply Air Blower Perf 12 1 2 Ton 11 7 Accessory Static Resistances 11 8 Blowe...

Page 3: ...holes provided in the base rails Spreaders whose length exceeds the largest dimension across the unit MUST be used across the top of the unit BEFORE LIFTING A UNIT MAKE SURE THAT ITS WEIGHT IS DISTRIB...

Page 4: ...re replaced on the unit to maintain an air tight seal THERMOSTAT The room thermostat should be located on an inside wall approximately 56 above the floor where it will not be subject to drafts sun exp...

Page 5: ...ocal codes or gas company requirements Refer to Table 3 The heating value of the gas may differ with locality The value should be checked with the local gas utility NOTE There may be a local gas utili...

Page 6: ...oad Maintaining proper gas pressure depends on three main factors 1 The vaporization rate which depends on a the temperature of the liquid and b the wetted surface area of the container or containers...

Page 7: ...ing 6 gasketed screws in each side plate 4 Secure the flange on the hood cover to the duct panel with 3 screws Use holes in the cover flange as a template and drill 3 holes 9 64 dia 26 drill into the...

Page 8: ...t 7 8 9 1 10 9 13 4 OUTDOOR FAN Two Per Unit PROPELLER DIA in 24 ea 24 ea 24 ea 24 ea FAN MOTOR HP 1 2 ea 1 2 ea 1 2 ea 3 4 ea NOM CFM TOTAL 2900 ea 3200 ea 3600 ea 4400 ea CONDENSER COIL ROWS DEEP 2...

Page 9: ...R CLEARANCES Front 24 Back 12 Less Economizer 36 With Economizer Left Side Filter Access 24 Less Economizer 54 With Economizer Right Side Cond Coil 24 Below Unit1 20 Above Unit2 72 with 36 maximum Hor...

Page 10: ...9 1 54 1 44 0 04 1 75 1 63 1070 0 86 1 46 1 36 0 54 1 68 1 57 0 20 1 89 1 76 0 04 2 11 1 97 1130 1 07 1 57 1 46 0 73 1 83 1 71 0 39 2 04 1 90 0 13 2 22 2 06 1175 1 27 1 67 1 56 0 94 1 92 1 79 0 58 2 1...

Page 11: ...0 2 72 2 54 0 11 3 03 2 83 1000 1 20 2 33 2 17 0 93 2 62 2 45 0 65 2 91 2 72 0 35 3 24 3 03 0 16 4 20 3 91 1050 1 42 2 55 2 37 1 14 2 86 2 67 0 85 3 17 2 96 0 62 4 06 3 79 0 39 4 53 4 22 1090 1 63 2 7...

Page 12: ...nd resets at 300 psig 10 3 A Low Pressure Switch Loss Of Charge to protect against loss of refrigerant charge Opens at 7 psig 3 and resets at 22 psig 5 If either one of the above safety controls opens...

Page 13: ...ture indicated in Table 10 It resets automatically The limit switch operates when a high temperature condition caused by inadequate supply air flow occurs thus shutting down the ignition control and c...

Page 14: ...djusting screw on the automatic gas valve Refer to Figure 12 Adjust as follows 1 Remove the cap on the regulator It s located next to the push on electrical terminals 2 To decrease the gas pressure tu...

Page 15: ...tions may require that this balancing be done by someone other than the equipment installer To check the supply air CFM after the initial balancing has been completed 1 Remove the dot plugs from the h...

Page 16: ...dial increment find the cubic feet of gas consumed per hour from Table 12 If the actual input is not within 5 of the furnace rating with allowance being made for the permissible range of the regulato...

Page 17: ...pplied along top of the burner COMBUSTION AIR DISCHARGE Visually inspect discharge outlet periodically to make sure that the buildup of soot and dirt is not excessive If necessary clean to maintain ad...

Page 18: ...osition a The draft motor has inherent protection If the motor shell is hot to the touch wait for the internal overload to reset b If the motor shell is cold with the room thermostat calling for heat...

Page 19: ...pilot burner is aligned properly with the carryover as described in PILOT CHECKOUT b Make sure that the carryovers on adjoining burners are screwed fast and are level with respect to one another 9 Ma...

Page 20: ...10 Code SBY 530 18 N10Y Unitary Products Group P O Box 1592 York Pennsylvania USA 17405 1592 Subject to change without notice Printed in U S A Copyright by York International Corporation 1995 All Rig...

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