Bryant 575C, 575B Iv. Compressor Lockout Device, V. PRELIMINARY OIL CHARGE 541A, A. Add Oil

IV. COMPRESSOR LOCKOUT DEVICE

The compressor lockout (CLO) device prevents the compres- sor from starting or running in a high pressure, loss-of- charge or freezestat open situation. Reset the CLO device by setting the thermostat to eliminate cooling demand and return it to the original set point. If the system shuts down again for the same fault, determine the possible cause before attempting to reset the CLO device.

V. PRELIMINARY OIL CHARGE (541A)

The compressor is factory charged with oil (see Table 1). When oil is checked at start-up, it may be necessary to add or remove oil to bring it to the proper level. Add oil only if necessary to bring oil into view in sight glass. Use only Bryant-approved compressor oil. One recommended oil level adjustment method is as follows:

A. Add Oil

Close suction service valve and pump down crankcase to 2 psig. Wait a few minutes and repeat until pressure remains steady at 2 psig. Remove oil fill plug above the sight glass, add oil through plug hole, and replace plug. Run compressor for 20 minutes and check oil level.

NOTE: Use only Bryant-approved compressor oil. Approved sources are:

Petroleum Specialties, Inc.. . . . . . . . . . . . . . . . . . . Cryol 150A

Texaco, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Capella WF-32

Witco Chemical Co.. . . . . . . . . . . . . . . . . . . . . . . . .Suniso 3GS

Do not use oil that has been drained out, or oil that has been exposed to atmosphere.

B. Remove Oil

Pump down compressor to 2 psig. Loosen the 1/4-in. pipe plug at the compressor base and allow the oil to seep out past the threads of the plug. Retighten plug when level is correct.

NOTE: The crankcase is slightly pressurized. Do not remove the plug, or the entire oil charge will be lost.

Small amounts of oil can be removed through the oil pump discharge connection while the compressor is running.

VI. START UNIT

The field disconnect is closed, the fan circuit breaker is closed, and the space thermostat is set above ambient so that there is no demand for cooling. Only the crankcase heater will be energized.

Next, close the compressor circuit breaker and then reset space thermostat below ambient so that a call for cooling is ensured.

NOTE: Do not use circuit breaker to start and stop the com- pressor except in an emergency.

After starting, there is a delay of at least 3 seconds before compressor starts.

VII. ADJUST REFRIGERANT CHARGE

CAUTION: Never charge liquid into the low- pressure side of system. Do not overcharge. During charging or removal of refrigerant, be sure indoor-fan system is operating.

CAUTION: Charge unit on cooling cycle only. If unit is charged on heating cycle, overcharging may occur.

Refer to Charging Charts Fig. 19A-19C and Table 8. Do not exceed maximum refrigerant charge. Vary refrigerant until the conditions of the chart are met. Note that charging charts are different from type normally used. Charts are based on charging the units to the correct subcooling for the various operating conditions. Accurate pressure gage and temperature sensing device are required.

Connect the pressure gage to the service port on the liquid line service valve. Mount the temperature sensing device on the liquid line, close to the liquid line service valve and insulate it so that outdoor ambient temperature does not affect the reading. Indoor airflow must be within the normal operating range of the unit. Operate unit a minimum of 15 minutes. Ensure pressure and temperature readings have stabilized. Plot liquid pressure and temperature on chart and add or reduce charge to meet curve. Adjust charge to conform with charging chart, using the liquid pressure and temperature to read chart.

If the sight glass is cloudy, check refrigerant charge again. Ensure all fans are operating. Also ensure maximum allow- able liquid lift has not been exceeded. If charged per chart and if the sight glass is still cloudy, check for a plugged filter drier or a partially closed solenoid valve. Replace or repair, as needed.

VIII. CHECK HEATING CYCLE OPERATION

Place thermostat selector switch at HEAT and reset the space set point above ambient temperature so that a call for heating is ensured. Compressor will start within 5 minutes. Observe system operation.

IX. CHECK COMPRESSOR OIL LEVEL (541A)

After adjusting the refrigerant charge, allow the system to run fully loaded for 20 minutes. Running oil level should be within view in the crankcase sight glass. Stop compressor at the field power supply disconnect and check the crankcase oil level. Add oil only if necessary to bring the oil into view in the sight glass. If oil is added, run the system for an addi- tional 10 minutes, then stop and check oil level. If the level remains low, check the piping system for proper design for oil return; also check the system for leaks.

If the initial check shows too much oil (too high in the sight glass) remove oil to proper level. See Preliminary Oil Charge section for proper procedure for adding and removing oil.

When the above checks are complete, repeat the procedure with the unit operating at minimum load conditions. Unload the compressor by disconnecting the field-control circuit lead

at TB2 Y2 .

Reconnect the field-control circuit lead when checks are complete.

X. FINAL CHECKS

Ensure all safety controls are operating, control panel covers are on, and the service panels are in place.

Table 8 — Maximum Refrigerant Charge

	UNIT		R-22
			(lb)
575B		072	27.0
575C		090	34.2
		120	34.2
541A		180	62.0

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