Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 103

■ Outdoor power circuit board
TBU, TBV, TBW
Connect the compressor (MC)
Voltage among phases:
10-230V AC
TBP2
Connect to the DCL
TAB connector
on X52CA
Connect to the RS
resistor
TBP1
Connect to the DCL
OCH800A_103
Brief check of the power module
If they are short-circuited, it means that they are broken.
Measure the resistance in the following points (connectors, etc.).
1. Check of the diode module (DB1 or DB2)
[L1]–[P1], [L2]–[P1], [L3]–[P1], [L1]–[N1], [L2]–[N1], [L3]–[N1]
2. Check of IPM (IC700)
[P2]–[U], [P2]–[V], [P2]–[W], [N2]–[U], [N2]–[V], [N2]–[W]
Note: The marks [L1], [L2], [L3], [N1], [N2], [P1], [P2], [U], [V], and [W]
shown in the diagram are not actually printed on the board.
IPM (IC700)
[P2]
[W]
[V]
[U]
[N2]
[P1] [N1] [P1]
[L1] [L2] [L3] [L3]
CN2
Connect to the outdoor controller circuit board (CN2)
– : Power circuit board → Transmitting signal to
the controller board (0–5 V DC)
– : Zero cross signal (0–5 V DC)
– : Not used
– : 15 V DC
– : 15 V DC
[ : (−) , ,
[N1]
[L2] [L1]
, : (+)]
Diode module
(DB1, DB2)
TBL3
TBL2
TBL1
Connect to the
outdoor noise
filter circuit board
(LO1,LO2,LO3)
208/230 V AC
CN6
Thermistor
<Heat Sink>
(TH8)
CN4
Connect to the
outdoor circuit
board (CN4)