Chromalox PQ410-4 service manual Limited Warranty

14.STANDARD HEAT TRANSFER SYSTEM TROUBLE SHOOTING CHART

	Problem	Cause	Corrective Action
		System temperature too high for oil	See fluid manufacturer’s data for
		causing vapor lock	maximum oil temperature
		Vapors lock due to steam or air in oil	Bleed air & steam from system, change
	Insufficient suction pressure (0 or		oil if problem continues
J	vacuum), pump noisy, gauges
		Net positive suction pressure too low	Raise expansion tank to increase suction
	vibrating, discharge pressure low		head, static head should be 4-5 psig.
	(below 20 psig)
			(See expansion tank location No. 6)
		Strainer plugged	Remove and clean strainer
		Valve closed	Check all valves
	High discharge pressure over 40 psig,	System piping blocked or restricted	Check all valves, check strainer
K	pressure gauges fluctuating rapidly,		Check process piping sizing, check for
	pump noisy, expansion tank normal,	Process piping blocked or restricted	closed valves or improperly installed
	system operating on bypass relief		automatic valves, check all bleed
	valve		valves for air or steam
		Steam or water in oil	Bleed system, change oil
		Expansion tank too low	Expansion tank should be mounted 15 ft.
L	Expansion tank overflows or “burps”		above system
	(over 220°F)
		Expansion tank line too short	Lengthen expansion tank line to cool oil
			and provide cold oil seal
		Tank too small for system	Check volume on process piping
		Over-temperature control open	Set thermostat above process temperature
M	Control relay #1 will not close		and reset
		Pressure switch not closed	See N
		Switch set wrong	Set pressure switch to approximately 5 psi
			over suction gauge pressure
N			Check pump & motor rotation, see arrow
	Pressure switch will not close	Pump running backwards	on motor, reverse phase lead on circuit
			breaker
		Not enough or no fluid in system	Check fluid levels in expansion tank,
			make sure all valves are open
		Pump cavitating	See O
			Bleed system periodically until all air or
		Air or steam in system	stem is removed
			Insufficient bleed valves in process
O
	Pump noisy and/or cavitation		piping to remove trapped air
		Contaminated oil	Change oil
		Pump damaged by overtightened
		packing gland	Replace pump
		Insufficient suction pressure	Suction pressure should be 4-5 psig

Limited Warranty:

Please refer to the Chromalox limited warranty applicable to this product at

http://www.chromalox.com/customer-service/policies/termsofsale.aspx.

2150 N. RULON WHITE BLVD., OGDEN, UT 84404

Phone: 1-800-368-2493 www.chromalox.com