Midea MCD-18HRFN1-QRC4 Service Manual page 137

2.4.4.6. E5 malfunction (For three phases units)
E5 display
Voltage protection
Check whether the voltage
range of P-N on IPM module is
normal? DC277-356V for 18K/
24KBtu/h; DC277-410V for
36KBtu/h
Yes
Replace the power board,
then check whether the
system can run normally
No
Check whether the voltage
range of P-N on IPM module is
normal? DC 350-650V
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
Electrical Control System
No Check the power supply
Yes
Yes
Yes
Yes
Trouble is solved
Troubleshooting
143