Mitsubishi Heavy Industries SRK20ZJX-S Service Manual page 60

CAUTION- HIGH VOLTAGE
High voltage is produced in the control box. Don't touch
electrical parts in the control box for 5 minutes after the
unit is stopped.
Color Marks
Mark Color
Power supply
BK Black
1 Phase
RD Red
220-240V 50Hz
WH White
OR Orange
BR Brown
TB1
YE Yellow
L
Y／G Yellow／Green
N
TB2
1 BK
2
UNIT A
3
TB3
1
2
UNIT B
3
◆Power source and serial
signal inspection
① to ②: AC 220/230/240V
② to ③ : Normal if the voltage
oscillates between DC 0
and approx. 20V
FUSE
250V 15A
BK BK
R
IN
WH
WH
S
IN
Y／G
G1
Y／G
G
Y／G
WH
CNA
RD
PWB 2（SUB）
BK
WH
CNB
BR
CNHEAT CN20S G2
Y／G
WH RD WH
HEATER 20S
◆Inspection of electronic
expansion valve
See page 62.
R
O
S
O
S-1
C-1
CNMAIN
CN20V
CNEEV1 CNTH
2
RD
M M
EEV EEV TH4
A B
◆Inspection of resistance value of sensor
Remove the connector and check the resistance value.
See the section of sensor characteristics on page 52.
◆Inspection power transistor
Remove the fasten terminal and test
output voltage
BK
R
WH
S
YE
T1
WH
S-2 R
OR
T2
RD
C-2
5
CNSUB
2
CN20V U RD
V WH
M
3～
BK
W
CM
PWB 1（MAIN）
M
CNFAN
FM0
CNTH
2 2 2
◆Inspection of outdoor
fan motor
See page 62.
TH1 TH2 TH3