Mitsubishi Electric MUY-TP-VF Series Service Manual page 24

C How to check miswiring and serial signal error
Initializing the determination of the power
receiving system
The microprocessor may have mistaken the
unit as a model receiving power from the
outdoor unit. Follow the procedure below to
start the determination of the power receiv-
ing system all over again.
1. Hold down the emergency operation
switch for 30 seconds. (Do not release the
switch even though a buzzer beeps once
in about 5 seconds. Keep holding down
the switch until a buzzer beeps again for
1 second after 30 seconds. Figure 1)
2. Turn off the power supply.
3. Wait for about 30 seconds.
4. Turn on the power supply.
5. Press the emergency operation switch.
6. The relay 52C will be turned on in 3 min-
utes.
Figure 1
Buzzer
0.5-second
ON
OFF
Beeps Beeps
Emergency
operation switch
ON
OFF
5-second
30-second
ON
A
• Turn OFF inverter-controlled lighting
equipment.
• Turn OFF the power supply and then
turn ON again.
• Press the emergency operation switch.
• Reinstall ei-
After the relay
ther the unit
52C is turned on
or the light
3 minutes later, is
away from
miswiring or the
No
each other.
serial signal error
• Attach a filter
indicated?
on remote
Yes
control
receiving
section of
the indoor
B
unit.
OBH816
Turn OFF the power supply.
Is there rated voltage in the
power supply?
1. Turn ON the power supply.
2. Press the emergency operation switch.
Has the relay 52C been turned on 3 minuets later ?
No
[The relay will be turned on in 3 to 7 seconds by
bridging the timer short mode point (Refer to 11-7.).]
Has the miswiring or the serial error
been indicated?
Is there any miswiring, poor
contact, or wire disconnec-
tion of the indoor/outdoor
connecting wire?
1-second
Turn OFF the power supply. Make sure again that the
indoor/outdoor connecting wire is correctly connected.
With the indoor/outdoor connecting wire connected, bridge
between S2 and S3 on the outdoor terminal block. 1
<Preparation of the remote controller>
Beeps
While pressing both OPERATION SELECT button and
B TOO COOL button on the remote controller at the same
time, press RESET button.
First, release RESET button.
Hold down the other two buttons for another 3 seconds.
Make sure that the indicators on the LCD screen shown in
the right figure are all displayed. Then release the buttons.
(Setting up the failure mode recall function)
OFF
Aim the remote controller at the indoor unit, and press OPER-
ATE (OFF/ON) button. The relay 52C will be turned on, and the
outdoor unit will be energized.
Is the rated supply voltage applied
between the S1 and S2 on the
outdoor terminal block? (Check of
supply voltage)
Is there approximately 250 V DC – 370
V DC between DB61 (+) and DB61
(–) on the inverter P.C. board in the
outdoor unit? (Voltage check of the
inverter P.C. board in the outdoor unit)
Does the LED on the inverter P.C.
board in the outdoor unit repeat
"3.6-second-OFF and 0.8-second-
ON quick blinking" for 3 minutes
after the outdoor unit is energized?
(Check the blinking pattern within 3
minutes after LED is turned on. Af-
ter 3 minutes, LED will blink 6 times
whether the inverter P.C. board in
the outdoor unit is normal or not.)
Replace the indoor electronic control
P.C. board.
3 Be sure to release the failure-mode recall function after checking.
No
Yes
Yes
No
Indication of miswiring
Yes
Indication of serial signal error
OPERATION
INDICATOR lamp
Continuous blinks
Correct them.
Yes
No
A
No
Yes
No
2 Be careful of 140
Yes
V DC – 280 V DC
residual charge in
the capacitor on the
main inverter circuit.
No
Yes
3
24
Check the power supply.
NOTE: Use the wireless remote controller of
MSZ-HJ25VA-
E2
alog OBB647.).
The remote controller has the indication
of "HEAT" and a button for it, but HEAT
mode cannot be used since MSY-TP
series are cooling only model.
The remote controller has the indication
of "ECONO COOL" and a button for
it, but ECONO COOL mode cannot be
used since it is not available on MSY-
TP series.
1 Make sure that the wiring is correct. If the pro-
cedure is performed without correcting miswir-
ing, it may lead to damage to the P.C. board.
Is there any problem in the
indoor/outdoor connecting wire,
such as the damage of the wire,
intermediate connection, poor
contact with the terminal block?
No
Replace the
inverter P.C.
board in the
outdoor unit. 2
Replace the
inverter P.C.
board in the
outdoor unit. 2
(Refer to parts cat-
Replace
the indoor/
outdoor con-
necting wire.
Yes