Mitsubishi Electric MUZ-GL09NA-U1 Service Manual page 58

MUZ-GL18/24NA
MUZ-GL18/24NAH
MUY-GL18/24NA
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 the outdoor service manual.)
Does the LED on the inverter P.C. board or the outdoor electronic control P.C.
board repeat "3.6-second-OFF and 0.8-second-ON quick blinking"? 3
Is there amplitude of 10 to 20 VDC between the indoor terminal block
S2 and S3? <Confi rmation of serial signal>
A
• Turn OFF inverter-controlled lighting
equipment.
• Turn OFF the power supply and then
turn ON again.
• Press EMERGENCY OPERATION
switch.
• Reinstall
either the unit
or the light
away from
Is serial signal each other.
• Attach a fi lter
error indicated 6
No
on remote
minutes later?
control receiv-
Yes
ing section
of the indoor
unit.
B
OBH733D
Turn OFF the power supply.
Is there rated voltage in the power supply?
Turn ON the power supply.
Is there rated voltage between outdoor terminal block S1 and S2?
Press EMERGENCY OPERATION switch once.
Does the OPERATION INDICATOR lamp light
up? <Confi rmation of the power to the indoor
unit>
Is serial signal error indicated 6 minutes
later?
Turn OFF the power supply.
Check once more if the indoor/outdoor
B
connecting wire is not miswiring.
Bridge the outdoor terminal block S2 and
S3. 1
Turn ON the power supply.
Turn OFF the power supply.
Remove the bridge between outdoor terminal block S2 and S3.
GL18
Turn on the power supply.
Yes
Is there 2 VDC or less between CN10A
and GND (-) on the indoor electronic control
P.C. board?
Yes
Is there 2 VDC or less between
CN10A
the indoor electronic control P.C.
board?
Replace the indoor power
P.C. board.
No
Yes
Yes
No
Yes
No
Yes
A
1. Miswiring may damage indoor electronic control P.C.
board during the operation.
Be sure to confi rm 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.
(Except for outdoor unit of multi system type)
Yes
No
(Lighted
Yes
or not
lighted)
GL24
Replace the indoor electronic control P.C. board.
No
(+)
No
(+) and GND (-) on
No Yes
Replace the indoor elec-
tronic control P.C. board.
58
Check the power supply.
No
Check the wiring.
Is there any miswiring,
poor contact, or wire
disconnection of the Correct them.
Yes
indoor/outdoor connect-
ing wire?
No
No
Replace the inverter P.C. board or the outdoor
electronic control P.C. board. 2
2. Be careful of the residual voltage of smoothing
capacitor.
Is there 2 VDC or less between
CN10A (+) and GND (-) on
the indoor electronic control P.C.
board?
No
Yes