Bryant 581A B. High-Pressureand Low-PressureSwitches, C. Freeze Protection Thermostat FPT

B. High-Pressure and Low-Pressure Switches

If either switch trips, or if the compressor overtemperature switch activates, that refrigerant circuit will be automati- cally locked out by the CLO. To reset, manually move the thermostat setting.

C. Freeze Protection Thermostat (FPT)

An FPT is located on the top and bottom of the evaporator coil. They detect frost build-up and turn off the compressor, allowing the coil to clear. Once the frost has melted, the compressor can be reenergized by resetting the compressor lockout.

D. Evaporator Fan Motor Protection

A manual reset, calibrated trip, magnetic circuit breaker protects against overcurrent. Do not bypass connections or increase the size of the breaker to correct trouble. Determine the cause and correct it before resetting the breaker.

E. Condenser-Fan Motor Protection

Each condenser-fan motor is internally protected against overtemperature.

Fuses are also located in the control box and feed power to the condenser fan motors. Always replace blown fuses with the correct size fuse as indicated on the unit fuse label.

XIII. RELIEF DEVICES

All units have relief devices to protect against damage from excessive pressures (i.e., fire). These devices protect the high and low side.

XIV. CONTROL CIRCUIT, 24-V

Each control circuit is protected against overcurrent by a

3.2amp circuit breaker. Breaker can be reset. If it trips, determine cause of trouble before resetting. See Fig. 40-42 for wiring.

SEE DETAIL “C”

XV. REPLACEMENT PARTS

A complete list of replacement parts may be obtained from any Bryant distributor upon request.

XVI. DIAGNOSTIC LEDs

The IGC control board has a LED for diagnostic purposes. The IGC error codes are shown in Table 33.

Table 33 — IGC LED Indications

ERROR CODE	LED INDICATION
Normal Operation	On
Hardware Failure	Off
Fan On/Off Delay Modified	1 Flash
Limit Switch Fault	2 Flashes
Flame Sense Fault	3 Flashes
Five Consecutive Limit Switch Faults	4 Flashes
Ignition Lockout Fault	5 Flashes
Inducer Switch Fault	6 Flashes
Rollout Switch Fault	7 Flashes
Internal Control Fault	8 Flashes
Software Lockout	9 Flashes
LEGEND
IGC — Integrated Gas Unit Controller
LED — Light-Emitting Diode

NOTES:

1.There is a 3-second pause between error code displays.

2.If more than one error code exists, all applicable error codes will be displayed in numerical sequence.

3.Error codes on the IGC will be lost if power to the unit is interrupted.

Fig. 39 — Spark Gap Adjustment

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