Mitsubishi Heavy Industries SRC25ZS-W2 - Self Diagnosis Function

'09•SRK-DB-087D
(9) Checking the indoor electrical equipment
(a) Indoor unit PCB check procedure
(b) Outdoor unit
Is there voltage between terminal
blocks
①
and
②
? (AC 220/230/240
V)
Indoor electrical components
are normal.
Is the voltage between terminal
blocks
②
and
③
oscillating between
DC 0 and 20V?
Inspect power source
for outdoor unit.
Replace fuse.
Replace indoor unit PCB.
Is the fuse burnt out? (3.15 A)
NO
YES
YES
NO
YES
NO
(b) Indoor fan motor check procedure
1) Indoor unit PCB output check
① ④ ⑤
2) Fan motor resistance check
⑥⑤④③②①
⑥⑤④③②①
FM i
DC15V
Indoor unit PCB
DC 308-336V
DC several V
(4-6 V)
CNU
(–)
GND
Blue Yellow White Black Red
Sensor
Operation
mode
Phenomenon
Shortcircuit Disconnected wire
Heat exchanger
sensor
Cooling
Heating
Ourdoor air
temperature sensor
Cooling
Heating
Discharge pipe
sensor
All modes
Measuring point Resistance when normal
①

−
 ③
−
④ 
−
 ③
−
Measuring
point
Voltage range when
normal
①

−
−
−
 ③
④ 
−
 ③
⑤ 
−
 ③

Defrosting is performed for 10 minutes at approx. 35 minutes.
Defrosting is performed for 10 minutes at approx. 35 minutes.
k
M
'20 • SRF-SM-311
-
34
-
'09•SRK-DB-087D
(9) Checking the indoor electrical equipment
(a) Indoor unit PCB check procedure
(b) Outdoor unit
Is there voltage between terminal
blocks
①
and
②
? (AC 220/230/240
V)
Indoor electrical components
are normal.
Is the voltage between terminal
blocks
②
and
③
oscillating between
DC 0 and 20V?
Inspect power source
for outdoor unit.
Replace fuse.
Replace indoor unit PCB.
Is the fuse burnt out? (3.15 A)
NO
YES
YES
NO
YES
NO
(b) Indoor unit fan motor check procedure
1) Indoor PCB output check
① ④ ⑤
2) Fan motor resistance check
⑥⑤④③②①
⑥⑤④③②①
FM I
DC15V
Indoor PCB
DC 308
-
336V
DC several V
(4
-
6 V)
CNU
(–)
GND
Blue Yellow White Black Red
Sensor
Operation
mode
Phenomenon
Shortcircuit Disconnected wire
Heat exchanger
sensor
Cooling
Heating
Ourdoor air
temperature sensor
Cooling
Heating
Discharge pipe
sensor
All modes
Measuring point Resistance when normal
①

−
 ③
−
④ 
−
 ③
−
Measuring
point
Voltage range when
normal
①

−
 ③
④ 
−
 ③
⑤ 
−
 ③

Defrosting is performed for 10 minutes at approx. 35 minutes.
Defrosting is performed for 10 minutes at approx. 35 minutes.
k
M
-
-