Mitsubishi Heavy Industries SRK20ZJX-S Service Manual page 74

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
BK Black
Power supply
BL Blue
1 Phase
RD Red
220-240V 50Hz
WH White
OR Orange
BR Brown TB1
YE Yellow
Y／G Yellow／Green
TB2
UNIT A
UNIT B
UNIT C
◆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／
250V 20A
BK BK
R
L IN
WH WH
S
N IN
Y／G
G1
Y／G
G
Y／G
BK
1
WH
2 CNA
RD
3
BK
1
WH
2 CNB
BR
3
BK
1
WH
2
CNC
BL
3
CNHEAT CN20S G2
Y／G
WH RD
HEATER 20S
CNMAIN
PWB 2（SUB）
CNEEV1 CNEEV3 CNTH
2
WH RD BL
M M M
TH4
EEV EEV EEV
A B C
◆Inspection power transistor
Remove the fasten terminal and test
output voltage
BK
R
R
O
WH
S
S
O
T1
WH
S-1 S-2
T2
RD
C-2
C-1
5
CNSUB
2
CN20V U
CN20V
V
W
PWB 1（MAIN）
CNFAN
CNTH
2 2 2
◆Inspection of outdoor
fan motor
See page 109.
TH1 TH2 TH3
YE
R
OR
RD
WH
M
3～
BK
CM
M
FMo