L0/L8/L9 Troubleshooting; Check The Compressor - Midea VRF V4 Plus I Series Manual

R410A DC Inverter V4 Plus 50Hz

5.14.1 L0/L8/L9 troubleshooting

Step 1: Replace the modular with correctly wire connection and start the system, if system is still
malfunction, then go to step2 to check the compressor.
Step 2: Take out the compressor from the malfunction system, short-circuit the suction and the discharge,
vacuum dry and charge 0.3kg~0.4kg R410A, and then connect the U,V,W terminals to control box B which is
took apart from normal system.
If the compressor start normally, that means compressor is OK, control box A is malfunction, then check the
inverter module.
If the compressor could not start normally, that means the compressor is malfunction, the go to step 3 to

check the compressor.

Control box A
which is took
apart from
malfunction
system.
Step 3: Check the compressor
Measure the resistance between each two of U, V, W terminals, all the resistance should be the same
and equal to 0.9~5 Ohms. (Fig. A and Fig. B)
Measure the resistance between each of U, V, W terminals to ground (Fig. C), all the resistance should be
the same and trend to be infinity (Fig. D), otherwise the compressor has been malfunction, needs to be
replaced.
110
Fig. A
Fig. C
MCAC-VTSM-2014-04
Control box B
which is took
apart from
normal system.
Compressor
which is took
apart from
malfunction
system.
Fig. B
Fig. D
Troubleshooting