Mitsubishi Electric PU(H)Y-P250YGM-A, Service Handbook

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[
IX
Troubleshooting ]
4240
4245 Overload pro-
tection When the greater output
current (Iac) than the
Imax (Arms), or THHS of
more than 90 °C is de-
tected for 10 minutes in a
row. (1) Short cycle of the air pas-
sage
Check that the waste heat from the
outdoor unit fan is not short cycled.
(2) Air passage blockage Check that the heat sink cooling air
passage is not blocked.
(3) Power supply Check whether the power supply
voltage is 342V or more.
(4) Faulty wiring Check for cooling fan wiring.
(5) THHS failure Check for THHS sensor resistor.
In the case of 4240: THHS1
In the case of 4245: THHS5
(6) Compressor INV board
failure and cooling fan fail-
ure
Ensure that the heasink temperature
is 55 °C or more and that 220~240V
is applied to the inverter PCB con-
nector CNFAN when the inverter is
on.
(7) Cooling failure Check the cooling fan operation un-
der the above operating conditions.
(8) Current sensor (ACCT)
failure
Refer to 9 [4]-6-(4).
"Current sensor ACCT"
(9) Compressor Inverter cir-
cuit failure
Refer to 9 [4]-6-(2) [4].
"Check whether the inverter is dam-
aged".
(10) Compressor failure Check that the compressor has not
overheated during operation.
-> Check the refrigerant circuit
(oil return section).
Replace the compressor
when no fault is found.
Error Code
Error definition and error
detection method
Cause Check method and remedy
Imax
P250 model 27 Arms
P500 model 27 Arms