Och636A - Mitsubishi Electric PUZ-A12NKA7 Service Manual

10-9. TEST POINT DIAGRAM
Outdoor controller circuit board
PUZ-A12NKA7
PUZ-A18NKA7
PUY-A12NKA7
PUY-A18NKA7
PUZ-A12NKA7-BS
PUZ-A18NKA7-BS
PUY-A12NKA7-BS
PUY-A18NKA7-BS
Note: PUZ-A12//18NKA checks solder side.
AC in (L, N)
N L
21S4
4-way valve
Connect to AC Reactor
P
L1
Diode (DS1)
N1
N
P N1 L1 N
Diode (DS2)

OCH636A

Brief Check of POWER MODULE
Usually, they are in a state of being short-circuited if they are broken.
Measure the resistance in the following points (connectors, etc.). If they
are short-circuited, it means that they are broken.
1. Check of Diode (DS1, DS2)
P - L1, P - N1, N - L1, N - N1
2. Check of Q1
P - N
3. Check of IPM
P - N , P - U , P - V , P - W , N - U , N - V , N - W
P-N keeps being shirt-circuited until the smoothing condenser is
charged by a tester.
Note: T he marks, P , N , L , L1, N1, U , V and W shown in the
diagram are not actually printed on the board.
Communication power supply
D71 Voltage
CNSW
24 V DC
Connect to switch
board
P U V W N
N P
IPM
Q1
65
<CAUTION> TEST POINT CNF11 is high voltage.
CNDM
1–2: I nput of low-level sound
priority mode
1–3: I nput of external contact point
CN51
External signal output
• Compressor operating signal
• Drain hose heater operating signal
LEV-A,B
Linear expansion valve
TH4
Thermistor <Discharge>
TH3
Thermistor <Liquid>
TH6/7
Thermistor
<2-Phase Pipe/Ambient>
TH32
Thermistor <Suction>
TH33
Thermistor
<Comp. surface>
CNF1
Connect to the fan motor
7
1–4: 250–330 V DC
6
5 5–4: 15 V DC
4 6–4: 0–6.5 V DC
7–4: 15 V DC (When stopped)
7.5 V DC (When operated)
1
(0–15 V pulse)
CN3
Thermistor <Heat sink>
63H
High pressure switch
Connect to compressor
W
(U, V, W)
V
Voltage among phases 5–180 V
U