Mitsubishi SRK19CNS-S, Technical Manual

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'14•SRK-T-164
Trouble of outdoor unit Insufficient refrigerant amount, Faulty power transistor, Broken compressor wire
Service valve close, Defective EEV, Defective outdoor PCB
．
◆
(1)
(1)
main
AC
AC
AC
Does 52X1 relay operate properly?
'09•SRK-SM-087D
(8) Checking the indoor electrical equipment
(a) Indoor PCB check procedure
(b) Outdoor unit
Is there voltage between terminal
blocks
①
and
②
? (AC 220V)
Indoor electrical components
are normal.
Is the voltage between terminal
blocks ② and ③ oscillating between
DC 0 and 20V?
Inspect
If the package components
are not damaged, replace the
fuse and perform an operation
check again.
Compressor stop.
power source
for outdoor unit.
Replace indoor PCB.
Is the fuse burnt out? (3.15 A)
NO
YES
YES
NO
YES
NO
(b) Indoor unit fan motor check procedure
(i) Indoor PCB output check
① ④ ⑤
(ii) Fan motor resistance check
⑥ ⑤ ④ ③ ② ①
⑥ ⑤ ④ ③ ② ①
FM
I
DC15V
Indoor PCB
DC 308~336V
DC several V
(4~6 V)
CNU
(–)
GND
Blue Yellow White Black Re
d
Sensor
Operation
mode
Phenomenon
Shortcircuit Disconnected wire
Heat exchanger
sensor
Cooling
Ourdoor air
temperature sensor
Cooling
Discharge pipe
sensor
All modes
Measuring point Resistance when normal
① − ③
−
④ − ③
−
Measuring
point Resistance when
normal
① − ③
④ −
⑤ −
③
k
1)
2)
3)
③
several V (4 ~ 6V)