ATS CyberChiller Series Compressor Short Cycles, Head Pressure is too Low, Suction Pressure too Low, System Short of Capacity, Compressor Fails to Start

CyberChiller Series Installation, Operation & Maintenance Manual

SYMPTOM PROBABLE CAUSE RECOMMENDATION

Head Pressure is too Low a. Loss of refrigerant (indicated by bubbles in the sight glass).

Repair leak and recharge system.

Suction Pressure too Low	a. Expansion valve stuck in the open	Repair or replace valve.
	position (indicated by abnormally cold
	suction line).
	b. Low charge, flash gas in liquid line	Repair leak and recharge system.
	(indicated by bubbles in sight glass).
	c. Clogged drier/strainer (feels cool to	Replace drier/strainer.
	the touch).
	d. Obstructed expansion valve (indicat	Replace valve.
	ed by loss of capacity).
	e. Loss of control fluid from expansion	Replace valve or control head.
	valve control head (indicated by
	bubbles in the sight glass).
Compressor Fails to Start	a. Temperature setpoint too high.	Adjust to desired temperature.
	b. Compressor internal protector	Check compressor for short circuit or
	is open.	ground.
	c. Complete loss of refrigerant charge	Locate and repair leak. Recharge
	(low pressure safety switch).	system.
	d. Condenser pressure too high (high	Check condenser for obstructions.
	pressure safety switch).
	e. Minimum off time has not expired.	Wait for time to expire.

System Short of Capacity a. Low refrigerant (indicated by bubbles in sight glass).

b. Expansion valve stuck or obstructed (short cycling or continuous running).

c. Clogged drier/strainer (feels cold).

Check for leaks Repair and recharge system.

Remove valve and clear obstruction or replace valve.

Replace with new drier/ strainer.

Compressor Short Cycles a. Low line voltage causing	Check power source for cause of low
compressor to overheat.	line voltage.
b. Reduced flow rate.	Check pump and strainer.
c. Lack of refrigerant	Check for leak. Repair and recharge
	system.

(©October, 2006) 4-4