Phenomenon Observed After Shortcircuit, Wire Breakage On Sensor - Mitsubishi SCM40ZS-S Technical Manual

(8) Phenomenon observed after shortcircuit, wire breakage on sensor

(a) Indoor unit
Operation
Sensor
mode
Cooling
Room temperature
sensor
Heating
Cooling
Heat exchanger
sensor
Heating
Cooling
(1)
Humidity sensor
Heating
Note (1) SRK 50ZMX-S, 35, 50ZS-S, SRF only.
■ Humidity sensor operation
Failure mode
①
②
①②
① ②
(b) Outdoor unit
Operation
Sensor
mode
Cooling
Heat exchanger
sensor
Heating
Cooling
Ourdoor air
temperature sensor
Heating
Discharge pipe
All modes
sensor
(9) Checking the indoor electrical equipment
(a) Indoor PCB check procedure
Is there voltage between terminal
blocks ① and ② ? (AC 220/230/240
V)
YES
Is the fuse burnt out? (3.15 A)
YES
Is the voltage between terminal
blocks ② and ③ oscillating between
DC 0 and 20V?
YES
Indoor electrical components
are normal.
(b) Indoor unit fan motor check procedure
1) Indoor PCB output check
DC several V
(4~6 V)
Shortcircuit
Freezing cycle system protection trips and stops the compressor.
Control input circuit resding
Shortcircuit
Compressor stop.
Defrost operation is not performed.
The compressor cannot pick up its speed owing to the current
safe so that the designed capacity is not achieved.
The compressor cannot pick up its speed owing to the heating
overload protection so that the designed capacity is not achieved.
NO
Inspect power source
for outdoor unit.
NO
Replace fuse.
NO
Replace indoor PCB.
-
(–)
GND
Phenomenon
Air-conditioning system operation
Phenomenon
Defrost operation is performed for 10 minutes at approx. 35 minutes.
Defrost operation is performed for 10 minutes at approx. 35 minutes.
214
-
DC 308~336V
'16 • SCM-T-199
Disconnected wire
'09•SRK-DB-087D
Disconnected wire
① ④ ⑤