Bryant 580G manual Vii. Filter Drier, Viii. Thermostatic Expansion Valve Txv, X. Relief Devices

VII. FILTER DRIER

Replace whenever refrigerant system is exposed to atmosphere.

VIII. THERMOSTATIC EXPANSION VALVE (TXV)

Each circuit has one. It is nonadjustable and is factory set to maintain 10 to 13° F superheat leaving the evaporator coil. Controls ¯ow of liquid refrigerant to the evaporator coils.

IX. PROTECTIVE DEVICES

A. Compressor Protection

Overcurrent

Each compressor has one manual reset, calibrated trip, mag- netic circuit breaker. Do not bypass connections or increase the size of the circuit breaker to correct trouble. Determine the cause and correct it before resetting the breaker.

Overtemperature

Each 06D type compressor has an internal protector to pro- tect it against excessively high discharge gas temperatures.

Crankcase Heater

Each compressor has a crankcase heater to prevent absorp- tion of liquid refrigerant by oil in the crankcase when the com- pressor is idle. Since power for the crankcase heaters is drawn from the unit incoming power, main unit power must be on for the heaters to be energized.

IMPORTANT: After a prolonged shutdown or service job, energize the crankcase heaters for 24 hours before starting the compressors.

B. 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. If the evaporator-fan motor is replaced with a different horsepower motor, resizing of the circuit breaker is required. Contact Application Engineering.

C. Condenser-Fan Motor Protection

Each condenser-fan motor is internally protected against overtemperature.

D. High- and Low-Pressure Switches

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

E. Freeze Protection Thermostat (FPT)

Freeze protection thermostats are located on the evaporator coil for each circuit. One is located at the top and bottom of each circuit. They detect frost build-up and turn off the com- pressor, allowing the coil to clear. Once the frost has melted, the compressor can be reenergized.

X. RELIEF DEVICES

All units have relief devices to protect against damage from excessive pressures (i.e., ®re). These devices are installed on the suction line, liquid line, and on the compressor.

XI. CONTROL CIRCUITS

A. 24-V Circuit

This control circuit is protected against overcurrent by a 3.2-amp circuit breaker (CB4). Breaker can be reset. If it trips, determine cause of trouble before resetting.

B. 115-V Circuit

This control circuit is protected against overcurrent by a 5.0-amp circuit breaker (CB3). Breaker can be reset. If it trips, determine cause of trouble before resetting.

XII. COMPRESSOR LOCKOUT LOGIC

If any of the safeties trip, the circuit will automatically reset (providing the safety has reset) and restart the compressor in 15 minutes. If any of the safeties trip 3 times within a 90-minute period, then the circuit will be locked out and will require manual resetting by turning off either the unit dis- connect or the control circuit breaker.

XIII. REPLACEMENT PARTS

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

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