Chromalox PQ410-4 service manual Standard Heat Transfer System Trouble Shooting Chart

14.STANDARD HEAT TRANSFER SYSTEM TROUBLE SHOOTING CHART

	Problem	Cause	Corrective Action
		Main power feed off	Turn on main power
		Circuit breaker off	Turn on circuit breaker
A
	Power light off	Control transformer
		Primary fuse blown	Replace fuse
		Secondary fuse blown	Replace fuse
		Transformer bad	Check and/or replace
		Pilot light blown	Replace bulb
		Float switch open	Add oil to system
B	Power light on, pump will not start		If no float switch, jumper terminals 4 & 5
		Motor overloads tripped	Reset overloads, check running current
		Motor starter bad	Check motor starter coil
C	Power light on, pump light on, motor	Motor fuse blown	Replace fuse, check motor overloads
	not running	Motor burned out	Replace motor, check motor for overload
		Broken belt	Check and replace belt
D	Power light on, pump light on, motor	Broken coupling	Check and replace coupling
			Turn off system and rotate pump by hand
	running, pump not running
		Pump jammed by slag or foreign object	if jammed, disassemble and clean pump.
			Check and clean strainer.
	Power light on, pump light on,	Control relay #1 not closed	See M
E
	motor running, pump running heat	Heat on-off switch in off position	Turn switch to on
	will not come on
		Process control ITC-1 set too low	Set process control to desired temperature
			See items, pump noisy, see O;
		No oil flow	insufficient suction pressure, see J:
			high discharge pressure, see K
F
	Insufficient heat	Process piping too small or restricted	Check process piping, check heat transfer
			area of platen, etc.
		Heater fuses blown	Check and replace fuses
		Heater elements burned out	Check continuity and resistance of
			elements
		Excessive operating pressure over	See K
		40 psig
		Packing gland loose	Check and adjust packing gland nuts per
			manufacturer’s recommendations
G
	Pump packing gland leaking	Wrong pump specified	Use mechanical seals or sealless pumps
			where no oil leaks can be tolerated
			Mechanical seals on pumps should be
		Improper cooling of seals	water cooled over 350°F.
			Failure to do so will cause seal failure
			and leaks.
H			Check piping and flange alignment
	System leaks when filling	Rough handling during shipment	retighten and torque all bolts to
			specifications
		Expansion and contraction due to	Check all flange bolts and connections
I	System leaks at temperature and after	temperature has loosened connections	retighten and torque to manufacturer’s
			specifications
	cool down
		Wrong gasket materials	Replace gaskets as necessary, use spiral
			wound or Grafoil® gaskets

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