Mitsubishi Electric PUZ-A18NHA6 Service Manual page 59

10-6-5. Check method of power circuit board
PUZ-A18/24NHA6
PUY-A12/18/24NHA6
Power circuit 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 280–350V DC?
Yes
Is the voltage to the compressor
(U-V,U-W and V-W) balanced?
Yes
Normal
198–253 V AC
Noise
Filter
Circuit
Board
LI NI
TB1 L N
198–253 V AC
PUZ-A18/24NHA6-BS
PUY-A12/18/24NHA6-BS
Note: To check the voltage of the parts on this board with a tester is difficult due to its location.
Test points are limited.
No
No
No
Power circuit board
7
6
5
4
3
2
1
Check the breaker and power supply.
Check wiring.
Check power circuit board.
Check noise filter circuit board.
Check wiring.
Check model setting switch SW6
on the outdoor controller circuit board.
Replace the power circuit board.
U-V 10–250 V AC
U
V-W 10–250 V AC
W-U 10–250 V AC
V
Comp
W
7 6 5 4 3 2 1
CNDC
(PNK)
3
Conv.
1
Circuit
290–350 V DC
Circuit diagram