Mitsubishi Electric CITY MULTI PUHY-400YMF-B Service Handbook page 172

Checking code Meaning, detecting method
1 When pressure sensor detects
5201 Pressure
sensor 1 kg/cm
abnormality during operation, outdoor unit
(Variable once stops with 3 minutes re-
capacity unit) starting mode, and restarts if
the detected pressure of pres-
sure sensor exceeds 1 kg/cm
(0.098 MPa) immediately be-
fore restarting.
2 If the detected pressure of
sensor is less than 1 kg/cm
(0.098 MPa) immediately be-
fore restarting, error stop is
commenced displaying 5201.
3 Under 3 minutes restarting
mode, LED displays intermit-
tent fault check.
4 During 3 minutes after com-
pressor start, defrosting and 3
minutes after defrosting opera-
tions, trouble detection is ig-
nored.
5301 IDC sensor/ • If IDC
circuit just before the inverter starts,
abnormality or
(Variable • If IDC
capacity unit) during inverter operation after
5 seconds has passed since
the inverter started when the
INV board's SW1-1 is OFF.
1) Pressure sensor trouble.
2 G (0.098 MPa) or less
2) Inner pressure drop due to a leak-
age.
3) Broken cover.
2 G 4) Coming off of pin at connector por-
tion, poor contact.
5) Broken wire.
6) Faulty thermistor input circuit of MAIN
2
G board.
20 A peak is detected 1) Contact is faulty.
10 A peak is detected 2) The current sensor (DCCT) is con-
nected with reverse polarity.
3) An error was made in the SW1-1
setting.
4) The INV board is defective. The cur-
rent sensor (DCCT) is defective.
Cause
–169–
Checking method & Countermeasure
Refer to Troubleshooting of pres-
sure sensor.
Check the contacts of CNCT on the
INV board.
Check the DCCT polarity.
• With SW1-1 OFF, is the inverter's
output wiring open?
• With SW1-1 OFF, is a compressor
which is not specified for this model
connected to the inverter's output?
If none of the items in 1) to 3) is appli-
cable, and if the trouble reappears
even after the power is switched on
again, replace the INV board and the
DCCT (when replacing the circuit
board, be sure to connect all the con-
nectors, ground wires, etc. securely)
by the following procedure.
1 Replace the INV board only. If it
recovers, the INV board is defec-
tive.
2 If it does not recover, reinstall the
INV board and replace the DCCT.
If it recovers, the DCCT is defec-
tive.
If it does not recover after 1 and 2
above, both the INV board and the
DCCT are defective.