Bryant 581B036--072, 581C024--060 Heating Service Analysis, Problem Cause Remedy

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Table 40— Heating Service Analysis

 

 

 

PROBLEM

CAUSE

REMEDY

Burners Will Not

Misaligned spark electrodes.

Check flame ignition and sensor electrode positioning. Adjust as needed.

Ignite.

 

 

No gas at main burners.

Check gas line for air purge as necessary. After purging gas line of air, allow gas

 

 

to dissipate for at least 5 minutes before attempting to relight unit.

 

 

Check gas valve.

 

Water in gas line.

Drain water and install drip leg to trap water.

 

No power to furnace.

Check power supply, fuses, wiring, and circuit breaker.

 

No 24 v power supply to control circuit.

Check transformer. Transformers with internal overcurrent protection require a

 

 

cool-down period before resetting. Check 24-v circuit breaker; reset if neces-

 

 

sary.

 

Miswired or loose connections.

Check all wiring and wirenut connections.

 

Burned-out heat anticipator in thermostat.

Replace thermostat.

 

Broken thermostat wires.

Run continuity check. Replace wires, if necessary.

Inadequate Heating.

Dirty air filter.

Clean or replace filter as necessary.

 

Gas input to unit too low.

Check gas pressure at manifold. Clock gas meter for input. If too low, increase

 

 

manifold pressure or replace with correct orifices.

 

Unit undersized for application.

Replace with proper unit or add additional unit.

 

Restricted airflow.

Clean filter, replace filter, or remove any restrictions.

 

Blower speed too low.

Use high speed tap, increase fan speed, or install optional blower, as suitable

 

 

for individual units, Adjust pulley.

 

Limit switch cycles main burners.

Check rotation of blower, thermostat heat anticipator settings, and temperature

 

 

rise of unit. Adjust as needed.

 

Too much outdoor air.

Adjust minimum position.

 

 

Check economizer operation.

Poor Flame

Incomplete combustion (lack of

Check all screws around flue outlets and burner compartment. Tighten as nec-

Characteristics.

combustion air) results in:

essary.

 

Aldehyde odors, CO (carbon monoxide),

Cracked heat exchanger.

 

sooting flame, or floating flame.

 

 

Overfired unit — reduce input, change orifices, or adjust gas line or manifold

 

 

pressure.

 

 

Check vent for restriction. Clean as necessary.

 

 

Check orifice to burner alignment.

Burners Will Not

Unit is locked into Heating mode for a

Wait until mandatory one-minute time period has elapsed or reset power to

Turn Off.

one minute minimum.

unit.

Table 41—Perfect HumidityAdaptive Dehumidification System Subcooling Mode Service Analysis

PROBLEM

CAUSE

 

REMEDY

Subcooling Mode (Liquid Reheat)

No power to control transformer from

Check power source and evaporator-fan relay. Ensure all

Will Not Energize.

evaporator-fan motor.

wire connections are tight.

 

No power from control transformer to liquid line

1.

Fuse open; check fuse. Ensure continuity of wiring.

 

solenoid valve.

2.

Low-pressure switch open. Cycle unit off and allow

 

 

 

low-pressure switch to reset. Replace switch if it will

 

 

 

not close.

 

 

3. Transformer bad; check transformer.

 

Liquid line solenoid valve will not operate.

1.

Solenoid coil defective; replace.

 

 

2.

Solenoid valve stuck open; replace.

 

Liquid line solenoid valve will not open.

Valve is stuck closed; replace valve.

Low System Capacity.

Low refrigerant charge or frosted evaporator coil.

1.

Check charge amount. Charge per Fig. 55---58.

 

 

2.

Evaporator coil frosted; check and replace low-pres-

 

 

 

sure switch if necessary.

Loss of Compressor Superheat

Thermostatic expansion valve (TXV).

1.

Check TXV bulb mounting, and secure tightly to suc-

Conditions with Subcooling/Reheat

 

2.

tion line.

Dehumidification Coil Energized.

 

Replace TXV if stuck open or closed.

Table 42—Perfect HumidityAdaptive Dehumidification System Hot Gas Reheat Mode Service Analysis

PROBLEM

CAUSE

 

REMEDY

Reheat Mode Will Not Energize.

No power to control transformer from

Check power source and evaporator-fan relay. Ensure all

 

evaporator-fan motor.

wire connections are tight.

 

No power from control transformer to hot gas

1.

Fuse open; check fuse. Ensure continuity of wiring.

 

line solenoid valve

2.

Low-pressure switch open. Cycle unit off and allow

 

 

 

low-pressure switch to reset. Replace switch if it will

 

 

 

not close.

 

 

3. Transformer bad; check transformer.

 

Hot gas line solenoid valve will not operate.

1.

Solenoid coil defective; replace.

 

 

2.

Solenoid valve stuck closed; replace.

 

Low refrigerant charge or frosted evaporator coil.

1.

Check charge amount. Charge per Fig. 55---58.

 

 

2.

Evaporator coil frosted; check and replace low-pres-

 

 

 

sure switch if necessary.

Loss of Compressor Superheat

Thermostatic expansion valve (TXV).

1.

Check TXV bulb mounting, and secure tightly to suc-

Conditions with Subcooling/Reheat

 

2.

tion line.

Dehumidification Coil Energized.

 

Replace TXV if stuck open or closed.

Excessive Superheat.

Liquid line solenoid valve will not operate.

Valve is stuck, replace valve.

 

Hot gas line solenoid valve will not close.

Valve is stuck; replace valve.

581B,C

57

Image 57
Contents Installation Instructions Provide Unit Support Install External Trap for Condensate DrainField Fabricate Ductwork Rig and Place UnitRoof Curb Details Install Gas Piping Install Flue HoodRoof Curb Alignment 581B 036-072 Base Unit Dimensions 581C 024-060 Base Unit Dimensions Field Control Wiring Field Power SupplyHeat Anticipator Settings Make Electrical ConnectionsBase Unit 581B Physical Data 581BUnit Size 581B Base Unit 581C Physical Data 581CUnit Size 581C Power Wiring Connections 581C024---060 Electrical Data 581CElectrical Data 581B Assembly Adjust Factory-Installed OptionsPerfect Humidity Adaptive Dehumidification System Manual Outdoor DamperTypical Perfect Humidity t Adaptive Dehumidification System Outdoor-Air Damper With Hood Attached Supply Air Sensor Temperature Resistance Values Supply Air Temperature SAT SensorTemperature F Outdoor Air Lockout SensorOutdoor Dry Bulb Changeover Economi$er IV Control ModesEconomi$er IV Sensor Usage Differential Dry Bulb ControlEconoMi$er IV Wiring Minimum Position Control Exhaust Set Point AdjustmentDamper Movement ThermostatsDemand Controlled Ventilation DCV Enthalpy Changeover Set Points Belt Drive Motors Dehumidification of Fresh Air with DCV ControlBelt Drive Motor Mounting CO2Sensor Standard SettingsAccessory Static Pressure 581B Fan Rpm at Motor Pulley Setting With High-Static MotorEvaporator-Fan Motor Data Standard Motor Evaporator-Fan Motor Data High-Static Motors581C Outdoor Sound Power Total Unit 581B Outdoor Sound Power Total UnitARI Octavebands Rating Unit Weighted ARI Octave Bands Unit Rating1100 Rpm Bhp1200 1300Rpm Bhp Watts Watts Rpm Bhp 1200 Rpm Bhp Watts1600 17001642 2333 1704 Rpm Bhp Watts 15002600 Watts Rpm Bhp 18002700 2800Bhp Watts Rpm 2700 2800 2900 3000Bhp 600 Bhp Watts 900 Watts RpmWatts Rpm Bhp 900 Bhp Watts 1700 1800 1900 20001900 2000 2100 2200 2300 2400 2500 800 350 904 438 999 535 1087 640 1169 753 913 569 913 569 1010 715 Refrigerant Service Ports Internal WiringUnit Preparation Gas PipingCompressor Rotation CoolingMain Burners Heating Safety ReliefVentilation Continuous Fan Operating SequenceSubcooling Mode Hot Gas Reheat ModeHeating Units With Economi$er Evaporator Coil CleaningCondenser Coil One-Row CoilsEconoMi$er IV Adjustment Condenser-Fan AdjustmentHigh Pressure Switch Loss-of-Charge SwitchPerfect Humidity System Charging Low Charge CoolingC06142 Flue Gas Passageways 581C 3 TON Charging Chart 581C 5 TON Charging Chart LED Error Code Description Limit SwitchRemoval and Replacement of Gas Train See Combustion-Air BlowerReplacement Parts OFM Economi$er IV Troubleshooting Unit TroubleshootingLED Error Code Service Analysis Economi$er IV Troubleshooting CompletionSymptom Cause Remedy LED OFFProblem Cause Remedy Heating Service AnalysisCooling Service Analysis Inputs Outputs EconoMi$er IV Input/Output LogicCatalog No. II581B---C---36---1 Preliminary Information