Mitsubishi Electric PUZ-A12NKA7 Service Manual page 55

10-6-3. Check method of power circuit board
PUZ-A24NHA7
PUZ-A24NHA7-BS
Power board check
Is the voltage of main incoming power
198–253 V AC?
Yes
Is the voltage of CNDC(PNK) on outdoor
controller circuit board 280–380 V DC?
Yes
Is the voltage to the compressor
(U-V,U-W and V-W) balanced?
Yes
Normal
U-V 10V-270V AC
V-W 10V-270V AC
W-U10V-270V AC
U
V
Comp
W
Outdoor Controller
OCH636A
PUZ-A30NHA7
PUZ-A30NHA7-BS
Note: To check the voltage of the parts on this board with a tester is difficult due to its location.
No
No
Turn off the incoming power supply
and check the resistance of PTC1
and PTC2 on the noise filter circuit board.
PTC1 or PTC2 = open ?
• Replace the power board.
No
Power board
DCL
7 6 5 4 3 2 1
CNDC
(PNK)
1
3
Controller
280V-380V DC
Board
PUY-A24NHA7
PUY-A24NHA7-BS
Test points are limited.
• Check the breaker and power supply.
No
(normal)
• Check wiring.
• Check power board.
Yes (open)
• Check wiring.
• Check model setting switch SW6
• Replace the power board.
TIME CHART
ON
Power supply
OFF
ON
52C relay
OFF
ex. 48 Hz
COMP (Hz)
0 Hz
370–390 V
290/325 V
Bus bar voltage
0 V
(DC)
power on starts
208/230V
±10% AC
TB1
L1 L2
208/230V
10% AC
±
55
PUY-A30NHA7
PUY-A30NHA7-BS
on the outdoor controller circuit board.
208/230 V
min Hz
290/325 V
stop
Circuit diagram