Friedrich XQ10M10, EQ08M11, XQ06M10, XQ05M10, XQ08M10 service manual Low voltage

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	Set t-stat to coldest position. Test t-stat &
	inoperative or electronic control
		replace if inoperative
	board is bad
	Compressor hums but cuts off on	Hard start compressor. Direct test compressor.
Compressor	overload	If compressor starts, add starting components
does not run
	Open or shorted compressor	Check for continuity & resistance
	windings
	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
	thermistor or electronic board	inoperative switch or electronic board.
	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
	Thermistor or electronic board is bad,	Set to coldest position. Test t-stat or electronic
	T-stat open or inoperative	control board & replace if necessary.
	Dirty filter	Clean as recommended in Owner’s Manual
	Dirty or restricted condenser or	Use pressure wash or biodegradable cleaning
Does not cool or	evaporator coil	agent to clean
only cools slightly	Poor air circulation	Adjust discharge louvers. Use high fan speed
	Fresh air or exhaust air door open	Close doors. Instruct customer on use of this
	on applicable 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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