Refrigerant Shortage Trouble - Mitsubishi PUMY-P60NKMU Technical & Service Manual

Check code
1501
Abnormal points and detection methods
(1) Abnormal when all of the following conditions are satisfi ed:
1. The compressor is operating in HEAT mode
2.Discharge super heat is 80 [176 °F] or more.
3.Difference between TH7 and the TH3 applies to the formula of
(TH7-TH3 <5 )
4.The 63HS detects below 2.04MPa.
(2) Abnormal when all of the following conditions are satisfi ed:
1.The compressor is in operation
2.When cooling, discharge superheat is 80 [176 °F] or more
When heating, discharge superheat is 90
The High-pressure sensor detects below 2.32 MPa
●Diagnosis of defectives
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Is the outdoor stop valve (ball
valve) fully open ?
Is there a refrigerant leak?
Is 5104 displayed when restart?
Check relevant thiemistor wirings and
connector contacts of the controller
boards.
Is there any abnormality on
connectors such as a disconnection,
half-disconnection or breakage?
Disconnect the thermistor wiring and check
the resistance.
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OCH502C

Refrigerant shortage trouble

[194 °F] or more.
Diagnosis
No
Yes
Yes
(leaking)
(no leaking)
No
Yes
(5104)
(1501)
No
Yes
No
Causes and check points
Defective operation of stop valve (not fully open)
Defective thermistor
Defective outdoor contoroller board
Indoor LEV performance failure
Gas leakage or shortage
Defective 63HS
TH3 : Piping temperature thermistor
TH7 : Outdoor temperature thermistor
LEV : Linear expansion valve
63HS : High-pressure sensor
Open the stop valve (ball balve) fully.
Repair the refrigerant leak.
Refer to the diagnosis of check code 5104.
Connect the connector properly.
(Repair or replace it in case of a breakage.)
45
Chart 1 of 2
Remedy