Mitsubishi Electronics PUY-A12NHA2-BS, PUZ-A42NHA2-BS, PUZ-A30NHA2, PUY-A36NHA2 To the next

Error Code	Abnormal point and detection method	Case	Judgment and action
	Communication error with communica-	1 Data of transmission proces-	Turn off the power supply of outdoor unit and
	tion processor	sor or unit processor is not	indoor unit and FRESH MASTER or LOSSNAY
	Defective communication between unit	transmitted normally because	at the same time for 2 minutes or more, and
	processor and transmission processor	of accidental trouble such as	turn the power on again. System returns to nor-
	Note) The address and attribute display at	noise or thunder surge.	mal if abnormality was accidental malfunction.
A6	remote controller indicate the con-	2 Address forwarding from unit	If the same abnormality generates again,
(6606)	troller that detected abnormality.	processor is not transmitted	abnormality-generated controller may be defec-
		normally because of defective	tive.
		transmission processor hard-
		ware.
	NO ACK signal	Common factor that has no rela-	Always try the followings when the error
	1. Transmitting side controller detects	tion with abnormality source.	“A7” occurs.
	abnormal if a massage was transmitted	1 The unit of former address
	but there is no reply (ACK) that a mes-	does not exist as address	1 Turn off the power supply of outdoor unit and
	sage was received. Transmitting side	switch has changed while the	indoor unit and FRESH MASTER or LOSS-
		unit was energized.	NAY at the same time for 2 minutes or more,
	detects abnormality every 30 seconds, 6
		2 Extinction of transmission wire	and turn the power on again. If malfunction
	times continuously.	voltage and signal is caused by	was accidental, the unit returns to normal.
	Note) The address and attribute displayed
		over-range transmission wire.	2 Check address switch of abnormality gener-
	at remote controller is indicate the
		• Maximum distance ······200m	ated address.
	controller that did not reply (ACK).
		[656ft]	3 Check disconnection or looseness of abnor-
		• Remote controller line ··(12m	mality generated or abnormality detected
		[39ft])	transmission wire (terminal block and con-
		3 Extinction of transmission wire	nector)
		voltage and signal is caused by	4 Check if tolerance range of transmission wire
		type-unmatched transmission	is not exceeded.
		wire.	5 Check if type of transmission wire is correct
		Type ······	or not.
		With shield wire-
		CVVS, CPEVS	If there were some troubles of 1-5above,
		With normal wire (no shield)-	repair the defective, then turn off the power
		VCTF, VCTFK, CVV	supply of outdoor unit and indoor unit and
		CVS, VVR, VVF, VCT	FRESH MASTER or LOSSNAY at the same
		Diameter····1.25mm2 [AWG16]	time for 2 minutes or more, and turn the power
		or more	on again.
		4 Extinction of transmission wire	• If there was no trouble with 1-5above in sin-
		voltage and signal is caused	gle refrigerant system (one outdoor unit), con-
		by over-numbered units.	troller of displayed address or attribute is
		5 Accidental malfunction of	defective.
		abnormality-detected controller	• If there was no trouble with 1-5above in dif-
		(noise, thunder surge)	ferent refrigerant system (2 or more outdoor
A7		6 Defective of abnormality gen-	units), judge with 6.
(6607)		erated controller	6 If address of abnormality source is the
	2. If displayed address or attribute is out-	1 Contact failure of transmission	address that should not exist, there is the
	door unit, Indoor unit detects abnormali-	wire of outdoor unit or indoor	unit that memorizes nonexistent address
	ty when indoor unit transmitted to out-	unit	information. Delete useless address informa-
	door unit and there was no reply (ACK).	2 Disconnection of transmission	tion with manual setting function of remote
		connector (CN2M) of outdoor	controller.
		unit	Only the system FRESH MASTER or LOSS-
		3 Defective transmitting receiv-	NAY are connected to, or the system that is
		ing circuit of outdoor unit or	equipped with group setting of different
		indoor unit	refrigerant system.
			If there was no trouble with 1-6above,
			replace the controller board of displayed
	3. If displayed address or attribute is	1 During group operation with
			address or attribute.
	indoor unit, remote controller detects	indoor unit of multi- refrigerant
			If the unit does not return to normal, multi-con-
	abnormality when remote controller	system, if remote controller
			troller board of outdoor unit may be defective
	transmitted to indoor unit and there was	transmit to indoor unit while
			(repeater circuit).
	no reply (ACK).	outdoor unit power supply of
			Replace multi-controller board one by one to
		one refrigerant system is
			check if the unit returns to normal.
		turned off or within 2 minutes
		of restart, abnormality is
		detected.
		2 Contact failure of transmission
		wire of remote controller or
		indoor unit
		3 Disconnection of transmission
		connector (CN2M) of indoor
		unit
		4 Defective transmitting receiv-
		ing circuit of indoor unit or
		remote controller
			Continued to the next page.

43