Friedrich 2007 service manual Cooling only Room AIR Conditioners Troubleshooting Tips

COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem	Possible Cause	Action
	Low voltage	Check voltage at compressor. 115V & 230V units
		will operate at 10% voltage variance
	T-stat not set cold enough or inoperative	Set t-stat to coldest position. Test t-stat & replace
		if inoperative
	Compressor hums but cuts off on B10 overload	Hard start compressor. Direct test compressor. If
		compressor starts, add starting components
Compressor
does not run	Open or shorted compressor windings	Check for continuity & resistance
	Open overload	Test overload protector & replace if inoperative
	Open capacitor	Test capacitor & replace if inoperative
	Inoperative system switch	Test for continuity in all positions. Replace if
		inoperative
	Broken, loose or incorrect wiring	Refer to appropriate wiring diagrams to check
		wiring

Problem	Possible Cause	Action
	Inoperative system switch	Test switch & replace if inoperative
	Broken, loose or incorrect wiring	Refer to applicable wiring diagram
Fan motor	Open capacitor	Test capacitor & replace if inoperative
does not run	Fan speed switch open	Test switch & replace if inoperative
	Inoperative fan motor	Test fan motor & replace if inoperative (be sure
		internal overload has had time to reset)

Problem	Possible Cause	Action
	Undersized unit	Refer to industry standard sizing chart
	T-stat open or inoperative	Set to coldest position. Test t-stat & replace if
		necessary
	Dirty filter	Clean as recommended in Owner's Manual
	Dirty or restricted condenser or evaporator coil	Use pressure wash or biodegradable cleaning
Does not cool or		agent to clean
only cools slightly	Poor air circulation	Adjust discharge louvers. Use high fan speed
	Fresh air or exhaust air door open on applicable	Close doors. Instruct customer on use of this
	models	feature
	Low capacity - undercharge	Check for leak & make repair
	Compressor not pumping properly	Check amperage draw against nameplate. If not
		conclusive, make pressure test

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