Panasonic CU-2S18NBU-1 service manual Indoor high Check indoor heat Exchanger

Diagnosis	Abnormality
	or	LED	LED	LED	LED	LED	LED	Abnormality	Protection	Problem	Check location
display	Protection	6	5	4	3	2	1	Judgment	Operation
	control
										Indoor high	• Check indoor heat
	Indoor high										exchanger
				○	○	○		―	―	pressure
H98	pressure										• Air filter dirty
										protection
	protection									(Heating)	• Air circulation
											short circuit
	Indoor										• Check indoor heat
										Indoor freeze	exchanger
	operating unit			○	○	○
H99								―	―	protection	• Air filter dirty
	freeze
	protection									(Cooling)	• Air circulation
											short circuit
	4-way valve			○	○	○	○	4 times		4-way valve	• 4-way valve
F11	switching							happen within	―	Switching	• Lead wire and
	abnormality							30 minutes		abnormal	connector
											• Check indoor/
											outdoor
										Wrong wiring and	connection wire
											and pipe
	Indoor standby							3 times		connecting pipe,
											• Indoor heat
			○							expansion valve
F17	units freezing							happen within	―		exchanger sensor
										leakage, indoor
	abnormality							40 minutes		heat exchanger	lead wire and
											connector
										sensor open circuit
											• Expansion valve
											lead wire and
											connector
	Power factor							4 times		Power factor
	correction		○				○				• Outdoor PCB
F90								happen within	―	correction circuit
	(PFC) circuit										faulty
	protection							10 minutes		abnormal
	Refrigeration		○			○		2 times		Refrigeration	• Insufficient
F91	cycle							happen within	―		refrigerant or valve
										cycle abnormal
	abnormality							20 minutes			close
	Compressor		○			○	○	4 times		Compressor	• Power transistor
F93	abnormal							happen within	―	abnormal	module faulty or
	revolution							20 minutes		revolution	compressor lock
	Compressor							4 times		Compressor
	discharge		○		○						• Check
F94	pressure							happen within	―	discharge pressure	refrigeration
	overshoot							30 minutes		overshoot	system
	protection
	Outdoor cooling							4 times		Cooling high	• Check
			○		○		○				refrigeration
F95	high pressure							happen within	―	pressure
											system
	protection							20 minutes		protection	• Outdoor air circuit
	Power transistor							4 times		Power transistor	• PCB faulty
F96	module		○		○	○			―
								happen within			• Outdoor air circuit
	overheating									module overheat
	protection							30 minutes			(fan motor)
	Compressor		○		○	○	○	3 times		Compressor	• Insufficient
F97	overheating							happen within	―
										overheat	refrigerant
	protection							30 minutes
	Total running							3 times			• Check
			○	○						Total current	refrigeration
F98	current							happen within	―		system
										protection
	protection							20 minutes			• Power source or
											compressor lock
	Outdoor direct		○	○			○	Continuous		Power transistor	• Power transistor
F99	current (DC)							happen for 7	―	module current	module faulty or
	peak detection							times		protection	compressor lock

LED 1 illuminate is indicated that outdoor unit is operating normally. If the LED 1 is switched off or flashing, check the power supply and self-diagnosis indication.

●---------- Illuminate ○ ---------- Flashing

Blank ---------- OFF

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