Emerson VE, VH, DE, DH manual Compressor and refrigeration system troubleshooting

Troubleshooting

Table 23 Compressor and refrigeration system troubleshooting (continued)

Symptom	Possible Cause	Check or Remedy
	Defective or improperly set	Increase superheat or replace valve
	expansion valve
Refrigerant flooding	Evaporator fan motor or belt	Correct problem or replace fan motor and/or belts.
	Low condensing pressure	Check head pressure control device
	Slipping belts	Inspect and adjust
Blown valve plate or	Liquid refrigerant floodback or	See Symptom: Flooding
cylinder head in comp.	flooded start
	Blown valve plate or cylinder	Replace gaskets. Retorque cylinder head bolts to
	head gasket.	compressor manufacturer's specs.
	Leaky valve plate or worn valve	Replace valve plate assembly
	seats
Low compressor
	Leaky suction valves	Pump down, remove cylinder head examine valve and valve
capacity or inability to
		seats. Replace if necessary
pull down system
	Broken connecting rods or	Replace compressor.
	pistons
	Leaking liquid line solenoid valve	Replace valve if clean; clean out valve if dirty.
	or dirt in valve
	Slugging due to floodback of	See Symptom: Flooding
	refrigerant
	Bearings wiped because of loss	See Oil Pressure. Check for defective oil failure control.
	of oil
Compressor noisy
	Loose compressor or piping	Tighten clamps.
	support
	Broken connecting rods, valves	Replace compressor
	or other running gear
Pipe rattle	Loose pipe connections	Check pipe connections
	Blown valve plate or cylinder	See Symptom: Blown Valve Plate
	head gasket
	Broken suction or discharge	Replace valves and valve plate, if necessary.
	valve
Compressor running hot	Compression ratio too high	Check setting of high and low pressure switches. Check
		condenser-- is it plugged? Check that all evaporator and
		condenser fans are operating properly.
	Excessive blow-by into
	crankcase -work rings, valves, or	Replace gasket, valve plate, or compressor
	blown gasket
	Low-pressure switch erratic in	Check tubing to switch to see if clogged or crimped Check
	operation	for proper switch operation
	Insufficient refrigerant in system	Check for leaks, fix, and add refrigerant
Compressor cycles	Suction service valve closed	Open valve.
	Insufficient water flowing through
intermittently
	condenser or clogged	Adjust water regulating valve to condenser. Clean
	condenser, or dirty air cooled	condenser.
	condenser coils
	Discharge service valve not fully	Open valve
	open

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