Mitsubishi Electronics MUZ-GB50VA service manual Outdoor unit failure mode table

3. Outdoor unit failure mode table

MUZ-GB50VA

The left lamp of	Abnormal point	LED indication		Condition	Correspondence	Indoor/outdoor
OPERATION INDICATOR		(Outdoor P.C. board)				unit failure mode
	(Failure mode / protection)
lamp (Indoor unit)		LED 1	LED 2			recall function
OFF	None (Normal)	-	-
2-time flash	Outdoor power system	Lighting	Lighting	When over current protection stop is	• Check the connection
				continuously performed three times	of the compressor
				within 1 minute after the compressor	connecting wire.
				gets started, or when converter	• Refer to 10-6.A
				protection stop or bus-bar voltage	"How to check
				protection stop is continuously	inverter / compressor".
				performed three times within 3	• Check the stop valve.
				minutes after start-up.
3-time flash	Discharge temperature	Lighting	Once	When thermistor shorts or opens	• Refer to 10-6.B"Check
	thermistor			during compressor running.	of outdoor thermistors".
	Defrost thermistor	Lighting	Once
	Ambient temperature thermistor	Lighting	Twice
	Fin temperature thermistor	Lighting	3 times
	P.C. board temperature	Lighting	4 times		• Replace the outdoor
	thermistor				electronic control
					P.C. board.
	Outdoor heat exchanger	Lighting	9 times		• Refer to 10-6.B"Check
	temperature thermistor				of outdoor thermistors".
4-time flash	Over current	Once	Goes	When 28A current flow into intelligent	• Reconnect compressor
			out	power module.	connector.
					• Refer to 10-6.A"How to
					check inverter/
					compressor."
					• Check the stop valve.
5-time flash	Discharge temperature	Lighting	Lighting	When discharge temperature exceeds	•Check refrigerant circuit
				116°C during operation.	and refrigerant amount.
				Compressor can restart if discharge	• Refer to 10-6.G"Check
				temperature thermistor reads 100: or	of LEV".
				less 3 minutes later.
6-time flash	High pressure	Lighting	Lighting	When the outdoor heat exchanger	•Check refrigerant circuit
				temperature exceeds 70:	and refrigerant amount.
				during cooling or the indoor gas	• Check the stop valve.
				pipe temperature exceeds 70:
				during heating.
7-time flash	Fin temperature	3 times	Goes	When the fin temperature exceeds	• Check around outdoor
			out	87: during operation.	unit.
					• Check outdoor unit air
					passage.
					• Refer to 10-6.D"Check
	P.C. board temperature	4 times	Goes	When the P.C. board temperature	of outdoor fan motor".
			out	exceeds 70: during operation.
8-time flash	Outdoor fan motor	Lighting	Lighting	When failure occurs continuously	• Refer to 10-6.D"Check
				three times within 30 seconds after	of outdoor fan motor".
				the fan gets started.
9-time flash	Nonvolatile memory data	Lighting	5 times	When nonvolatile memory data	• Replace the outdoor
					electronic control
				cannot be read properly.
					P.C. board.
10-time flash	Discharge temperature	Lighting	Lighting	When the frequency of the	•Check refrigerant circuit
				compressor is kept 80Hz or	and refrigerant amount.
				more and the discharge	• Refer to 10-6.G"Check
				temperature is kept under 39:	of LEV".
				for more than 20 minutes.

NOTE : Blinking patterns of this mode differ from the ones of Troubleshooting check table (10-4.).

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