Mitsubishi Electric PQHY-P72ZLMU-A Service Handbook page 356

[ IX Troubleshooting ]
Items to be checked
[4] Put the heat source unit into
Check whether operation.
the inverter is Check the inverter output volt-
damaged. age after the inverter output
(During com- frequency has stabilized.
pressor opera-
tion)
HWE15150
Phenomena
1) Overcurrent-related problems oc-
cur immediately after compressor
startup.
Error code : 4250
Detail code : 101, 106, 107
2) There is a voltage imbalance be-
tween the wires.
Greater than 5% imbalance or 5V
- 347 -
Remedy
a. Check items [1] through
[3] for problems.
b. Check that high and low
pressures are balanced.
c. Check for compressor
flooding and refrigerant
flood back.
->If the problem persists
after restarting the unit
several times, see item "d
"
d. Check that there is a pres-
sure difference between
high and low pressures af-
ter compressor startup.
Check the high pressure
with LED monitor for
changes.
Replace the compressor if
there is no pressure differ-
ence. (the compressor
may be locked.)
Replace the INV board.
GB