Panasonic R410A Service procedures, Symptoms and Parts to Inspect, Remote, Alarm, Clear condition

						4. Service procedures
4-2. Symptoms and Parts to Inspect
	Remote	Alarm	Judgment condition	Clear condition		Judgment and
	controller	contents				correction
	alarm display
	P03	Abnormal discharge	Stops when temp. exceeds	Recovery at restart	1. Check refrigerant cycle
		temperature	232 ˚F.		(gas leak).
		• Discharge temp.			2. Electronic control valve
		detected at or			trouble
		above the specified			3. Check tubing sensor (TD).
		value.
	P04	High pressure	Stops when pressure	Recovery at restart	1. Check the high pressure
		switch is activated.	exceeds 600 psi.		switch connector is
		Compressor motor	Stops when temp. exceeds		securely connected.
		thermal protector is	230 ˚F.		2. Check the ourdoor unit heat
		activated.			exchanger is not clogged
					(cooling operation).
					3. Check the indoor unit air
					filter has not become
					clogged (heating operation)
	P05	Missing phase	Current value sent from MDC	Recovery at restart	1. Check R/S/T power.
		detected. (CT	on outdoor unit control PCB is		2. Check inverter control PCB.
		disconnected or AC	low.		3. Check outdoor unit control
		power trouble)	No AC power input for 3		PCB.
			minutes or longer: pre-trip - 5
	P15	Insufficient gas level	The following conditions	Recovery at restart	Check refrigerant cycle
		detected.	continue for 1 minute.		(gas leak).
			• Discharge temp. is 203 ˚F or
			higher.
			• Electronic control valve is at
			step 480.
			• Current value from MDC is
			2.0 A or less.
	P19	4-way valve locked	Indoor heat exchanger temp.	Recovery at restart	1. Check 4-way valve.
		• Judgment occurs	drops although compressors		2. Check 4-way valve wiring.
		after compressor	are ON in heating mode:		3. Check outdoor unit control
		has been ON for 5	[min(E1, E2)] ≤ 50 ˚F.		PCB.
		minutes.	Indoor heat exchanger temp.
			rises although compressors are
			ON in cooling mode:
			E2 ≥ 104 ˚F.
	P20	High-pressure	If MAX (C1,C2) is 142°F or	Recovery at restart	1. Refrigerant cycle
		protection trouble	higher, the compressor stops		overload operation
			one. The compressor restarts		2. Outdoor coil temperature
			three time, and if the		sensor C1 or C2		4
			temperature does not
			decrease to less than 142°F,
			the alert “P20” is displayed.
	P22	Outdoor unit fan	Inverter stops after alarm is	Recovery at restart	1. Position detection trouble
		motor trouble	detected		2. Overcurrent protection
		• Inverter protection			circuit at outdoor unit fan
		circuit was			motor was activated.
		activated, or lock			•	Check outdoor unit control
		was detected, at				PCB.
		outdoor unit fan			•	Refer to outdoor unit fan
		motor.				judgment methods.
	P26	Inverter protection	Inverter stops after alarm is	Recovery at restart	1. Stops immediately when
		circuit was	detected. Alarm is output		restarted.
		activated, or G-Tr	when inverter stops (pre-trip)		•	Layer short in the
		short-circuit (short	consecutively 4 times.			compressor
		time: 0.8 s or less)			2. Check inverter control
		in inverter control			PCB.
					•	Wiring trouble

4-5