Midea MCD-18HRFN1-QRC4 Service Manual page 136

Troubleshooting
2.4.4.5. E5 malfunction (For single phase units)
E5 display
Voltage protection
Check the voltage of
outdoor unit power supply,
whether the voltage
between L(1) and N is about
220~240VAC
Yes
Replace the power board,
then check whether the
system can run normally
No
Check whether the voltage
of IPM board P and N is
normal? DC277-356V for
18K/24K/30KBtu/h; DC277-
410V for 36K/48KBtu/h
No
Replace bridge rectifiers,
and then check whether the
system can run normally
No
Replace IPM board, and
then check whether the
system can run normally
No
Replace outdoor main board
142
No Check the power supply
Yes
Yes
Yes
Yes
Trouble is solved
Electrical Control System