Checking The Inverter For Damage During Compressor Operation; Checking The Fan Motor For Ground Fault And Coil Resistance Problems; Checking The Fan Board Error Detection Circuit At No Load - Mitsubishi Electric PURY-HP72 Service Handbook

[8-11 Troubleshooting Inverter Problems (YKMU) ]
8-11-5

Checking the Inverter for Damage during Compressor Operation

Items to be checked
Put the outdoor unit into operation.
Check the inverter output voltage af-
ter the inverter output frequency has
stabilized.
8-11-6

Checking the Fan Motor for Ground Fault and Coil Resistance Problems

Items to be checked
Remove fan motor winding. Check
insulation resistance and coil resis-
tance.
8-11-7

Checking the Fan Board Error Detection Circuit at No Load

Items to be checked
(1) Turn off breaker.
*Turn power off without fail.
(2) Remove fan board CNINV
and CNSNR connectors.
(3) Turn on breaker.
(4) Operate unit.
HWE13080
Phenomena
1) Overcurrent-related problems occur im-
mediately after compressor startup.
Error code : 4250
Detail code : 101, 102, 106, 107
2) There is a voltage imbalance between
the wires after the inverter output voltage
is stabilized.
Greater than the larger of the following
values: imbalance of 5% or 5V
Phenomena
1) Fan motor insulation failure.
If < 1 MΩ, Defect.
2) Fan motor wire failure.
Normal coil resistance is a few ohms.
(Changes with temperature)
Phenomena
1) Electrical current over load error.
Check code: 4255
Detail code: 101, 104
2) Logic error
Check code: 4225
Detail code:111
3) Position error on start up
Check code: 5305
Detail code: 132
- 301 -
Remedy
a. Check items 8-11-2 through 8-
11-4 for problems.
b. Check that high and low pres-
sures are balanced.
c. Check that no liquid refrigerant
is present in the compressor.
→Go to "d." when the problem
persists after compressor start-
up was repeated several times.
If normal operation is restored,
check the belt heater for prob-
lems.
d. Check that there is a pressure
difference between high and
low pressures after compres-
sor startup.
→Check the high pressure with
LED monitor for changes.
Replace the compressor if
there is no pressure difference.
(the compressor may be
locked.)
Replace the INV board if there is a
voltage imbalance.
Check the belt heater for problems if
there is no voltage imbalance.
→When the error occurred, liquid
refrigerant may have been present
in the compressor.
Remedy
Change fan motor.
Change fan motor.
Remedy
Change fan board.
Change fan board.
Normal
*After checking, return connector
CNINV & CNSNR.
GB