Midea M-Thermal Series Service Manual page 55

M‐Thermal Split
Procedure
Power supply for the main control board
and transformer is abnormal
The transformer of hydronic unit is
There is a source of electromagnetic
radiation near the unit, such as
high‐frequency transmitter or other high
strength radiation device
Communication wires P Q E between
main control board of outdoor unit and
hydraulic module have short circuited,
disconnected or misconnected
Replace outdoor unit main PCB and
hydronic box main PCB in turn
Notes:
1. Measure the voltages of transformer input port and out port. The input voltage of transformer is 220V AC, output voltage of transformer is 13.5V AC. If any
voltages is abnormal, the power supply for the main control board of hydraulic module and transformer will be abnormal.
2. Measure the voltages of transformer output port ports. If the voltages are not normal, the transformer has malfunctioned.
54
H0
1
No
2
malfunctioned
No
No
No
Midea CAC Confidential
Yes
Provide normal power supply
Yes
Replace the transformer
Yes
Remove the source of interference
Yes
Reconnect the communication wires
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