Midea M4OC-36HRFN1-M - Voltage Protection (E5) Diagnosis

9.4.2.5 E5(Voltage protection) error diagnosis and solution.
Error Code
E5
Malfunction decision
conditions
An abnormal voltage rise or drop is detected by checking the
specified voltage detection circuit.
Supposed causes
● Power supply problems.
● System leakage or block
● PCB faulty
Trouble shooting:
Voltage protection
Check the voltage of
outdoor unit power supply,
whether the voltage
between L(L1) and N (L2) is
about 187~253VAC
Check the power supply
Check whether the voltage
of IPM board P and N is
normal? DC277-356V for
18-27KBtu/h; DC277-410V
for 36KBtu/h
Replace bridge rectifiers,
and then check whether the
system can run
normally(Only for qua-
zone)
Replace IPM board, and
then check whether the
system can run normally
Replace outdoor main board
Yes
No
No
No
No
Yes
Trouble is solved
Yes
Yes