Mitsubishi Electronics MUY-D36NA, MUZ-D36NA, U1, MUZ-D30NA, MUY-D30NA service manual Muz

No.	Symptom	Indication		Abnormal point / Condition	Condition		Correspondence
		LED1	LED2
		(Red)	(Yellow)
20		Once	Lighting	Primary current protection	The input current exceeds 15 A.	• These symptoms do not mean any abnormality of
				Secondary current protection	The current of the compressor exceeds 15 A.
						the product, but check the following points.
				High-pressure protection	The indoor gas pipe temperature exceeds 113 °F (45 °C) dur-	• Check if indoor filters are clogged.
21		Twice	Lighting	(MUZ)	ing heating.	• Check if refrigerant is short.
				Defrosting in cooling	The indoor gas pipe temperature falls 37 °F (3 °C) or below	• Check if indoor/outdoor unit air circulation is short
						cycled.
					during cooling.
				Discharge temperature protec-	The discharge temperature exceeds 212 °F (100 °C) during	• Check refrigerant circuit and refrigerant amount.
22	Outdoor	3 times	Lighting			• Refer to 10-5.	"Check of LEV".
				tion	operation.
	unit oper-					• Refer to 10-5.	"Check of outdoor thermistors".
23	ates.	4 times	Lighting	Low discharge temperature	The frequency of the compressor is kept 80 Hz or more and	• Refer to 10-5.	"Check of LEV".
					the discharge temperature is kept under 102 °F (39 °C) for
				protection		• Check refrigerant circuit and refrigerant amount.
					more than 20 minutes.
						• This symptom does not mean any abnormality of
				Cooling high-pressure protec-	The outdoor heat exchanger temperature exceeds 136 °F (58	the product, but check the following points.
24		5 times	Lighting			• Check if indoor filters are clogged.
				tion	°C) during operation.	• Check if refrigerant is short.
						• Check if indoor/outdoor unit air circulation is short
						cycled.
25	Outdoor	9 times	Lighting	Inverter check mode	The unit is operated with emergency operation switch.	–
	unit oper-
26	ates	Lighting	Lighting	Normal	–	–

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