Mitsubishi Heavy Industries SRRM40HENG-L, Handbook, Page: 177 / 1106

175
SCM-HG (4 room)
Check fuse. There should be conductivity.
Note (1) SCM80HENG-L : 250V 30A
SCM100HENG-L : 250V 50A
Display lamp inspection
For confirming
electrical discharge
Room A
Power source 1 Phase 50/Hz
Room B
Room C
Room D
Tester probe
∞
Normal condition
,
+ (WH) + (WH)
.
+ (GR) + (GR)
Signal display
Room D
CNH
(White)
Condenser
(C101)
CNJ
(Black)
CN2
(White)
Reactor
White
.
mark
Tester probe (BK)
Tester probe (RD)
White
Brown
Gray
Red
Blue
Orange
GR
Green
Blue
Surge absorber
Black
White
Black
White
Black
White
Brown
FUSE
Red
Yellow
Black
Black
Gray
Approx. DC 280 V
P(+) P1
DS
CT
AB
1
B
W
L
N
23
1
2
3
1
23
1
2
3
C
NF
NF1
D
R2
R1 S1
BK WH
BK WH
G
2
(1)
3
14
S2
R T N
–
P+
Condenser
Power transistor
Printed circuit board
U
Red White Black
V
W
CM
CNA2 (Red)
CNA1
(White)
CNG
(Black)
CNF
(White)
CNE
(Yellow)
CND
(Blue)
CNC
(Red)
CNB
(White)
CNI
(Black)
CNS
(Red)
Black
Outdoor temperature thermistor
Heat exchanger thermistor
Discharge pipe thermistor
Black
Black
CNP
(Yellow)
CNO
(Blue)
CNN
(Red)
CNM
(White)
Room C
Room B
Room A
LED3
LED1
EEV
A
EEV
B
EEV
C
EEV
D
SV
A
SV
B
SV
C
SV
D
SV DF
FM
01
FM
02
20S
63H
LED2
SWA
SWB
SWC
Unit model set switch
SWD
ON OFF
LED4
LED5
LED6
Abnormality
display
Operation
display
LED7
●
Power supply and serial
signal inspection
1
to
2
: AC220V
2
to
3
: Normal if the voltage oscil
-
lates between DC 0 and approx. 12V
●
Inspection of capacitor
Check the charging characteristics with a tester. (Needle should swing and return slowly. Change the polarity and check again. If the needle returns, it is normal.)
●
Inspection of electronic expansion valve
To test if there is voltage. (Voltage is only applied to the electronic expansion valve when the valve angle is being changed.) Red to white Red to Orange Brown to yellow Brown to blue If the expansion valve does not operate as shown above, it is defective.
●
Inspecting the solenoid valve
SVA to D: Each room is operating. ON (AC220V) SVDf: When defrosting ON (AC220V)
●
Display lamp inspection
• LED 1 (Operating display lamp - Green) • LED 2 (Abnormality display lamp - Red) • LED 3 to 6: (Light display for each room -
Green)
• LED 7 (Red):
ON: Power supply and IC normal OFF: Power supply abnormality OFF or ON: IC abnormality ON or flashing: Protection function operating) ON when there is a serial signal being received among each of the indoor units. OFF during ignition, stop (including no connection), abnormality Service LED (for confirming discharge)
(When tester probes are inverted, the read
-
ing should be approx. 10~20
Ω
.)
●
Inspection of diode stack
●
Inspection of reactor conductivity
Remove the connector and check for conductivi
-
ty. It must be conductive.
●
Inspect power transistor.
Remove the fasten terminal and test out
-
put voltage.
●
Inspection of resistance value of discharge
-
pipe thermistor.
Remove the connector and check the resistance value. See the section of thermistor characteristics on page 169.
Normal if there is approximately DC 5 V 10 seconds after the power supply is turned on.
}
*
*
*
(b)
Outdoor unit inspection points
u
T
urn power supply of
f before inspecting.
(Do not touch any components in the controller box until LED 7 goes out.)
u
*
Check these points with the power
supply on.