MDV MDCA3-12HRDN1, Service Manual

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Troubleshooting
Electrical Control System 221
2.4.4.6. E4 malfunction
Judge 1: Outdoor condenser temp. sensor (T3) is malfunction
E4 display
No
No
Replace condenser temp. sensor(T3)
Check whether the wiring of the
condenser temp. sensor(T3) is
broken off
Check whether the resistance of
condenser temp. sensorT3) is wrong
refer to the Appendix 1
Yes
Connect the wiring well Yes
Judge 2: Outdoor ambient temp. sensor (T4) is malfunction
No
Replace outdoor ambient
temperature sensor (T4)
Check whether the wiring of the
outdoor ambient temperature
sensor (T4) is broken off
Check whether the resistance of
outdoor ambient temperature
sensor (T4) is wrong refer to the
Appendix 1
Yes
Connect the wiring well Yes
Judge 3: Compressor discharge temp. sensor (T5) is malfunction
No
Replace compressor discharge
temperature sensor (T5)
Check whether the wiring of the
compressor discharge temperature
sensor (T5) is broken off
Check whether the resistance of
compressor discharge temp. sensor
(T5) is wrong refer to the Appendix 2
Yes
Connect the wiring well Yes
No
Replace outdoor main PCB
No