Phenomenon Observed After Shortcircuit, Wire Breakage On Sensor - Mitsubishi Heavy Industries SCM50ZS-S1 Technical Manual

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

(a) Indoor unit
Sensor
Room temperature
sensor
Heat exchanger
sensor
(1)
Humidity sensor
Note (1) SRK 20-60ZSX-S(-W), SRK35, 50ZS-S(-W), SRF only.
■ Humidity sensor operation
Failure mode
①
②
①②
① ②
(b) Outdoor unit
Sensor
Heat exchanger
sensor
Ourdoor air
temperature sensor
Discharge pipe
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)
Operation
mode
Cooling
Heating
Freezing cycle system protection trips and stops the compressor.
Cooling
Heating
Cooling
Heating
Control input circuit resding
Operation
mode
Compressor stop.
Cooling
Defrost operation is not performed.
Heating
The compressor cannot pick up its speed owing to the current
Cooling
safe so that the designed capacity is not achieved.
The compressor cannot pick up its speed owing to the heating
Heating
overload protection so that the designed capacity is not achieved.
All modes
NO
Inspect power source
for outdoor unit.
NO
Replace fuse.
NO
Replace indoor PCB.
(–)
GND
Phenomenon
Shortcircuit
Air-conditioning system operation
Phenomenon
Shortcircuit
210
- -
DC 308~336V
'18 • SCM-T-251
Disconnected wire
'09•SRK-DB-087D
Disconnected wire
Defrost operation is performed for 10 minutes at approx. 35 minutes.
Defrost operation is performed for 10 minutes at approx. 35 minutes.
① ④ ⑤