Bryant Cooling cont, Integrated control, motor, units 589A048,060, 208/230, IFM does not run

Models: 589A 588A

1 52
Download 52 pages 50.86 Kb
Page 49
Image 49

Cooling (cont)

SYMPTOM

 

CAUSE

REMEDY

 

 

 

 

Integrated control

 

Blower wheel not secured to shaft

Properly tighten blower wheel to shaft.

motor

 

 

 

 

Insufficient voltage at motor

Determine cause and correct.

(units 589A048,060

 

 

 

 

208/230 v)

 

Power connectors not properly

Connectors should snap easily; do not

IFM does not run.

 

seated

force.

 

 

 

 

Integrated control

 

Motor programmed with a delay

Allow a few minutes for motor to shut off.

motor (units

 

pro®le

 

589A048,060

 

 

 

 

With thermostat in OFF the voltage

If measured voltage is more than 1¤2, the

208/230 v)

 

on G,Y1,Y/Y2,W with respect to

thermostat is incompatible with motor. If

IFM runs when it

 

 

common, should be 1¤2 of actual

voltage is less than 1¤2, the motor has failed.

should be off.

 

low voltage supply

 

 

 

 

 

 

 

 

Integrated control

 

Water dripping into motor

Verify proper drip loops in connector wires.

motor (units

 

 

 

589A048,060

 

 

 

 

Connectors not ®rmly seated

Gently pull wires individually to be sure they

208/230 v) IFM

 

 

 

are crimped into the housing.

operation is

 

 

intermittent.

 

 

 

IFM Ð Evaporator (Indoor) Fan Motor

 

 

Heating

SYMPTOM

CAUSE

 

REMEDY

 

 

 

Burners will not ignite.

Water in gas line

Drain. Install drip leg.

 

No power to furnace

Check power supply fuses, wiring, or circuit breaker.

 

No 24-v power supply to control

Check transformer.

 

circuit

NOTE: Some transformers have internal overcurrent

 

 

protection that requires a cool-down period to reset.

 

Miswired or loose connections

Check all wiring and wirenut connections.

 

Burned-out heat anticipator in

Replace thermostat.

 

thermostat

 

 

 

Broken thermostat wire

Run continuity check. Replace wire if necessary.

 

Misaligned spark electrodes

Check ¯ame ignition and sense electrode positioning.

 

 

Adjust as necessary.

 

No gas at main burners

1.

Check gas line for air. Purge as necessary.

 

 

 

NOTE: After purging gas line of air, wait at least

 

 

 

5 minutes for any gas to dissipate before attempt-

 

 

 

ing to light unit.

 

 

2.

Check gas valve.

Inadequate heating.

Dirty air ®lter

Clean or replace ®lter as necessary.

 

Gas input to furnace too low

Check gas pressure at manifold. Match with that on

 

 

unit nameplate.

 

Unit undersized for application

Replace with proper unit or add additional unit.

 

Restricted air¯ow

Clean or replace ®lter. Remove any restriction.

 

Blower speed too low

Use faster speed tap if available, or install alternate

 

 

motor.

 

Limit switch cycles main burners

Check rotation of blower, thermostat heat antic-

 

 

ipator settings, temperature rise of unit. Adjust as

 

 

necessary.

Poor ¯ame characteristics.

Incomplete combustion results in:

1.

Tighten all screws around burner compartment.

 

Aldehyde odors, carbon monox-

2.

Cracked heat exchanger. Replace.

 

ide, sooting ¯ame, ¯oating ¯ame

3. Unit over®red. Reduce input (change ori®ces or

 

 

 

adjust gas line or manifold pressure).

 

 

4.

Check burner alignment.

Ð49Ð

Page 49
Image 49
Bryant Cooling cont, Integrated control, units 589A048,060, 208/230, IFM does not run, motor units, should be off