Midea ESG-Inv M Series - H7 Voltage Protection

ESG-Inv M
47
Part 5 – Diagnosis and Troubleshooting
5.16 H7 Troubleshooting
Digital display output
Procedure
H7: Voltage protection
Power supply voltage is not within ±10%
of rated voltage or a phase is missing(for
3 phase model)
Yes
Provide normal power supply
No
Wires between main PCB, AC filter board
(for 3 phase model) and electric control
box power supply terminals are loose
Yes
Ensure the wires are connected properly
No
Set a multi-meter to buzzer mode and test
any two terminals of P N and U V W of the
inverter module. The buzzer sounds.
Yes
Replace the inverter module PCB.
No
The normal resistances of the fan motor
are 29.9-36.7Ω among U V W and infinite
between each of U V W and ground. Any
of the resistances differ from these
specifications.
Yes
Replace the fan motor
No
The normal resistances of the inverter
compressor are 1.5-2.5Ω among U V W
and infinite between each of U V W and
ground. Any of the resistances differ from
these specifications.
Yes
Replace the compressor.
MBT Confidential