Mitsubishi Electric CITY MULTI PUHY-400YMF-C Service Handbook page 162

Checking code Meaning, detecting method
4200 VDC 1 If VDC
sensor/circuit before the inverter starts.
abnormality 2 If VDC
before starting of and during
(Variable
operation of the inverter.
Capacity unit)
4210 Breaking of 1 If IDC
overcurrent tected during inverter opera-
(Variable tion.
capacity unit) 2 If the voltage of the INV
board's sensor circuit input is
what it should not normally be.
304 V is detected just 1) Power supply voltage is abnor-
mal.
750 V is detected just
2) The wiring is defective.
3) The rush current prevention
resistors (R1, 5) are defective.
4) The electromagnetic contactor
(52C) is defective.
5) The diode stack (DS) is defective.
6) The reactor (DCL) is defective.
7) The INV board is defective.
103 A peak is de- 1) The power supply voltage is
abnormal.
2) The wiring is defective.
3) The inverter/compressor is
defective.
-159-
Cause Checking method & Countermeasure
• Check if an instantaneous power
failure or power failure, etc. has
occurred.
• Check if the voltage is the rated
voltage value.
Check 1, the connections, 2, contact
at the connectors, 3 tightening torque
at screw tightened portions, 4, wiring
polarities, 5, for broken wires, and 6,
for grounding in the following wiring.
TB1A~NF~TB1B, TB1B~DS~[52C,
R1, R5]~[C2, C3]~IPM Wiring
CNDC1 (G / A) ~ CNVDC (INV) Wir-
ing
* Check if the wiring polarities are as
shown on the wiring diagram plate.
To judge failure of R1 and R5, go to
"Individual Parts Failure Judgment
Methods."
To judge failure of the 52C, go to
"Individual Parts Failure Judgment
Methods."
To judge failure of the DS, go to
"Individual Parts Failure Judgment
Methods."
To judge failure of the DCL, go to
"Individual Parts Failure Judgment
Methods."
If none of the items in 1) to 6) is
applicable, and if the trouble
reappears even after the power is
switched on again, replace the INV
board (when replacing the circuit
board, be sure to connect all the
connectors, ground wires, etc.
securely).
• Check if an instantaneous power
failure or power failure, etc. has
occurred.
• Check if the voltage is the rated
voltage value.
Check 1, the connections, 2, contact
at the connectors, 3 tightening torque
at screw tightened portions, 4, wiring
polarities, 5, for broken wires, and 6,
for grounding in the following wiring.
TB1A ~ DS ~ [52C, R1, R5] ~ [C2,
C3] ~ TRM Wiring
TRM ~ CNVDC Wiring
TRM ~ Compressor Wiring
[CN2-1, CN2-2, CN2-3, CN3]
~ TRM Wiring
* Check if the wiring polarities are as
shown on the wiring diagram plate.
* Check the coil resistances and in-
sulation resistance of the compres-
sor.
Go to "Treatment of Inverter/Compres-
sor Related Trouble."