Mitsubishi Electronics MUZ-GE12NA, MUY-GE12NA How to check miswiring and serial signal error

M How to check miswiring and serial signal error

Turn OFF the power supply.
Is there rated voltage in the power supply?
						Check the power supply.
			No
		Yes
	Turn ON the power supply.
							No
Is there rated voltage between outdoor terminal block S1 and S2?									Check the wiring.
		Yes
Press EMERGENCY OPERATION switch once.
Does the OPERATION INDICATOR lamp light
up? <Confirmation of the power to the indoor
unit>				No
		Yes			Is there any miswiring,
Is serial signal error indicated 6 minutes later?					poor contact, or wire
					disconnection of the						Correct them.
				No						Yes
		Yes			indoor/outdoor connect-
					ing wire?
								No

	A
	Turn OFF the power supply.
B	Check once more if the indoor/outdoor
	connecting wire is not miswiring.
	Short-circuit outdoor terminal block S2
	and S3. 1
	Turn ON the power supply.

1. Miswiring may damage indoor electronic control P.C. board during the operation.

Be sure to confirm the wiring is correct before the opera- tion starts.

3. Be sure to check this within 3 minutes after turning ON. After 3 minutes, LED blinks 6 times. Even when the inverter P.C. board or the outdoor electronic control P.C. board is normal, LED blinks 6 times after 3 minutes.

Is the bus-bar voltage of the inverter P.C. board or the outdoor electronic control P.C. board normal. (Refer

to "TEST POINT DIAGRAM AND VOLTAGE" in this manual.) No

Yes

Check of power supply. (Refer to 10-5..)

Does the LED on the inverter P.C. board or the outdoor electronic control P.C.					Replace the inverter P.C. board or the outdoor
board repeat "3.6-second-OFF and 0.8-second-ON quick blinking"?		3			electronic control P.C. board. 2
				No
	Yes			(Lighted
					2. Be careful of the residual voltage of smoothing
				or not
				lighted)	capacitor.
Turn OFF the power supply.
Remove the short-circuit between outdoor terminal block S2 and S3.
Turn ON the power supply.
				Check the wiring
Is there rated voltage between indoor terminal block S1 and S2?				If there are any error of the indoor/outdoor connecting wire:
				such as the damage of the wire, intermediate connection,
<Confirmation of power voltage>			No
				and/or poor contact to the terminal block, replace the indoor/
	Yes			outdoor connecting wire.

	Is there amplitude of 10 to 20 VDC between indoor terminal block S2
	and S3? <Confirmation of serial signal>			No
		Yes
	A	Is there 2 VDC or less between CN10A (+)
• Turn OFF inverter-controlled lighting
		and JPG (GND)(-) on the indoor electronic
equipment.		control P.C. board?
• Turn OFF the power supply and then		Yes	No
turn ON again.
• Press EMERGENCY OPERATION		Is there 2 VDC or less between			Is there 2 VDC or less between
switch.
		CN10A	(+) and JPG (GND)(-) on		CN10A	(+) and JPG (GND)(-) on
	• Reinstall	the indoor electronic control P.C.			the indoor electronic control P.C.		Yes
		board?			board?
	either the unit		No	Yes		No
	or the light
	away from	Replace the indoor power		Replace the indoor elec-
Is serial signal	each other.	P.C. board and the indoor		tronic control P.C. board.
error indicated 6	No • Attach a filter	terminal P.C. board
minutes later?	on remote
Yes	control receiv-
	ing section
	of the indoor
B	unit.

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