Midea MHC-96HWD1N1(A) Service Manual page 41

MCAC-UTSM-201503

E4: Ambient temp. T4/pipe temp. T3 sensor error/ E7: Discharge temp. sensor T7 error
E4: T3/T4/T7 sensor error
T3/T4/T7 port on main
control board is loose
No
T3/T4/T7 sensor is short circuit or
disabled (Using
measure resistance, if the resistance is
too small, the sensor is short circuit)
No
Outdoor main control
board is damaged
Case: There is no display on main control board, and the problem still exists after replacing main control
board. Voltage values on measuring plate (such as 220V, 5V, 12V, etc.) are normal; after measuring
resistance value of sensor, find that T4 thermo-bulb is earth-continuity, and further discover that the
thermal cable of T4 sensor is punched by bolt, as follows:
R410A Full DC Inverter Split Duct Type Technical Manual
Yes
a multimeter to
T4 sensor is worn out and
connected with sheet metal
Fasten the T3/T4 port
Yes
Replace the sensor
Replace the outdoor
main control board
After being reconnected, the
system becomes normal
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