Victory Refrigeration VM-1, VM-2, VM-2SL manual 29

TROUBLESHOOTING & SERVICING REFRIGERATION SYSTEM

	PROBLEM		POSSIBLE CAUSE		REMEDY
1.	Condensing unit fails to start - no	1.	Line disconnect switch open.	1.	Close start or disconnect switch.
	hum.	2.	Fuse removed or blown.	2.	Replace fuse.
		3.	Overload protector tripped.	3.	Determine reason and
		4.	Control stuck in open position.		correct/replace control.
				4.	Repair or replace control.
		5.	Wiring improper or loose.	5.	Check wiring against diagram.
2.	Condensing unit fails to start -	1.	Improperly wired.	1.	Check wiring against diagram.
	hums, but trips on overload	2.	Low voltage to unit.	2.	Determine reason and correct.
	protector.	3.	Starting capacitor defective.	3.	Determine reason and replace.
		4.	Relay failing to close.	4.	Determine reason and
		5.	Compressor motor has a winding		correct/replace if necessary.
				5.	Replace compressor.
			open or shorted.	6.	Replace compressor.
		6.	Internal mechanical trouble in
			compressor.
3.	Condensing unit starts, but fails	1.	Improperly wired.	1.	Check wiring against diagram.
	to switch off of “start” winding.	2.	Low voltage to unit.	2.	Determine reason and correct.
		3.	Relay failing to open.	3.	Determine reason and
					correct/replace if necessary.
		4.	Run capacitor defective.	4.	Determine reason and replace.
		5.	Excessively high discharge	5.	Check discharge shut-off valve,
			pressure.		possible overcharge, or
					insufficient cooling on condenser.
		6.	Compressor motor has a winding	6.	Replace compressor.
			open or shorted.	7.	Replace compressor.
		7.	Internal mechanical trouble in
			compressor.
4.	Condensing unit starts and runs,	1.	Additional current passing through	1.	Check wiring diagram. Check for
	but short cycles on overload		overload protector.		added fan motors, pumps, etc. con-
	protector.	2.	Low voltage to unit (or		nected to wrong side of protector.
			unbalanced if three phase.)	2.	Determine reason and correct.
		3.	Overload protector defective.	3.	Check current , replace protector.
		4.	Run capacitor defective.	4.	Determine reason and replace.
		5.	Excessive discharge pressure.	5.	Check ventilation, restrictions in
					cooling medium, restrictions in
		6.	Suction pressure too high.		refrigeration system.
				6.	For salad models, temperature
					control differential set to close-
		7.	Compressor too hot - return gas.		increase differential.
				7.	Check refrigerant charge (fix leak)
		8.	Compressor motor has a winding		add if necessary.
				8.	Replace compressor.
			shorted.
5.	Condensing unit runs but short	1.	Overload protector.	1.	See (4) above.
	cycles on...	2.	Thermostat.	2.	Differential set too close - widen.
		3.	High pressure cut-out due to:	3.	a. Check air or water supply to
			a. Insufficient air or water supply.
					condenser-correct.
			b. Overcharge.		b. Reduce refrigerant charge.
					c. Purge.
			c. Air in system.	4.
		4.	Low pressure cut-out due to:		a. Replace.
			a. Liquid line solenoid leaking.
					b. Replace.
			b. Compressor valve leak.
			c. Undercharge.		c. Fix leak, add refrigerant.
			d. Restriction in expansion		d. Replace device.
			device.
6.	Condensing unit operates for	1.	Shortage of refrigerant.	1.	Fix leak, add charge.
	prolonged periods or	2.	Control contacts stuck or frozen	2.	Clean contacts or replace control.
	continuously.		closed.	3.	Allow unit sufficient time for
		3.	Excessive heat load placed into
			cabinet.		removal of latent heat.
		4.	Prolonged or too frequent door	4.	Plan or organize schedule to
			openings.		correct condition.
		5.	Evaporator coil iced.	5.	Defrost.
		6.	Restriction in refrigeration	6.	Determine location and remove.
			system.	7.	Clean condenser.
		7.	Dirty condenser.
		8.	Filter dirty.	8.	Clean or replace.

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