Mitsumi electronic PKA-A12HA4, PKA-A18HA4 Cause, Countermeasure, Pipe temperature thermistor

Error Code	Abnormal point and detection method	Cause	Countermeasure
	Pipe temperature thermistor/	Defective thermistor	– Check resistance value of thermistor.
	Condenser-Evaporator (TH5)	characteristics	For characteristics, refer to (P1) above.
	The unit is in 3-minute resume protec-	Contact failure of connector	Check contact failure of connector (CN44) on
	tion mode if short/open of thermistor is	(CN44) on the indoor controller	the indoor controller board. Refer to 9-7.
	detected. Abnormal if the unit does not	board (Insert failure)	Turn the power on and check restart after
	get back to normal within 3 minutes. (The	Breaking of wire or contact	inserting connector again.
	unit returns to normal operation, if it has	failure of thermistor wiring	Operate in test run mode and check pipe <con-
	been reset normally.)	Temperature of thermistor is	denser/evaporator> temperature with outdoor
			controller circuit board. If pipe
	Constantly detected during cooling,
			<condenser/evaporator> temperature is exclu-
	drying, and heating operation (except
			sively low (in cooling mode) or high (in heating
	defrosting)	defective refrigerant circuit.
			mode), refrigerant circuit may have defect.
		Defective indoor controller
P9			Operate in test run mode and check pipe <con-
		board
			denser/evaporator> temperature with outdoor
			control circuit board. If there is
			extreme difference with actual pipe
			<condenser/evaporator> temperature, replace
			indoor controller board.
			There is no abnormality if none of above comes
			within the unit.
			Turn the power off and on again to operate.
			In case of checking pipe temperature	)
			with outdoor controller circuit board,
			be sure to connect A-control service
			(tool (PAC-SK52ST).
	Forced compressor stop	Drain pump trouble	Check the drain pump.
	(due to water leakage abnormality)	Drain defective	Check whether water can be drained.
	The unit has a water leakage abnor-	· Drain pump clogging
	mality when the following conditions, a)	· Drain pipe clogging
	and b), are satisfied while the above-	Open circuit of float switch	Check the resistance of the float switch.
	mentioned detection is performed.	Contact failure of float switch	Check the connector contact failure.
	a) The intake temperature subtracted	connector
	with liquid pipe temperature detects to	Dew condensation on float switch	Check the float switch leadwire mounted.
	be less than -10 [14	·Drain water descends along	Check the filter clogging.
	30 minutes. (When the drain sensor	lead wire.
PA	is detected to be NOT soaked in the	·Drain water waving due to filter
(2500)	water, the detection record of a) and b)	clogging.	Check the piping connection.
	will be cleared.)	Extension piping connection
	b) Drain float switch detects to be in the	difference at twin, triple, quad-
	water for more than 15 minutes.	ruple system.
	*Once the water leakage abnormality is	Miswiring of indoor/outdoor	Check the indoor/outdoor connecting wires.
	detected, abnormality state will not be	connecting at twin, triple, quad-
	released until the main power is reset.	ruple system.	Check the room temperature display of
		Room temperature thermistor/
		liquid pipe temperature thermis-	remote controller.
		tor detection is defective.	Check the indoor liquid pipe temperature dis-
			play of outdoor controller board.
	Remote controller transmission	Contact failure at transmission	Check disconnection or looseness of indoor
	error(E0)/signal receiving error(E4)	wire of remote controller	unit or transmission wire of remote controller.
	Abnormal if main or sub remote con-	All remote controllers are set	Set one of the remote controllers “main”
	troller cannot receive any transmission	as “sub” remote controller. In	if there is no problem with the action above.
	normally from indoor unit of refrigerant	this case, E0 is displayed on	Check wiring of remote controller.
	address “0” for 3 minutes.	remote controller, and E4 is
	(Error code : E0)	displayed at LED (LED1, LED2)	(Do not use cable 3 or more.)
	Abnormal if sub remote controller could	on the outdoor controller circuit	• The number of connecting indoor units:
	not receive for any signal for 2 minutes.	board.	max. 16 units
	(Error code: E0)	Miswiring of remote controller	• The number of connecting remote control-
	Abnormal if indoor controller board	Defective transmitting receiving	ler: max. 2 units
		circuit of remote controller	When the above-mentioned problem of	~
	cannot receive any data normally from	Defective transmitting receiving	are not applied,
E0	remote controller board or from other	circuit of indoor controller board	Diagnose remote controllers.
or	indoor controller board for 3 minutes.	of refrigerant addresses “0”.	a) When “RC OK” is displayed, remote con-
E4	(Error code: E4)	Noise has entered into the	trollers have no problem. Turn the power
	Indoor controller board cannot receive	transmission wire of remote	off, and on again to check. If abnormality
	any signal from remote controller for 2	controller.	generates again, replace indoor controller
	minutes. (Error code: E4)		board.
			b) When “RC NG” is displayed, replace
			remote controller.
			c) When “RC E3” or “ERC 00-06” is dis-
			played, noise may be causing abnormality.
			If the unit is not normal after replacing
			indoor controller board in group control,
			indoor controller board of address “0”
			may be abnormal.

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