Mitsubishi Electric PUHY-P120YHMU-A, Service Manual

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[
IX
Troubleshooting ]
- 165 - HWE0804A GB
1. Error Code
Open phase
2. Error definition and error detection method
ΠAn open phase of the power supply (L1 phase, L2 phase) was detected at power on.
ΠThe L3 phase current is outside of the specified range.
The open phase of the power supply may not always be detected if a power voltage from another circuit is applied.
3. Cause, check method and remedy
4102 (YHMU-A)
Cause Check method and remedy
(1) Power supply problem
Œ
Open phase voltage of the power supply
Œ
Power supply voltage drop
Check the input voltage to the power supply terminal block TB1.
(2) Noise filter problem
Œ
Coil problem
Œ
Circuit board failure
Œ
Check the coil connections.
Œ
Check for coil burnout.
Œ
Check that the voltage across TB21 and TB22 on the noise filter
board is 414V or above.
(3) Wiring failure Confirm that the voltage at the control board connector CNAC is
190 V or above.
If the voltage is below 190, check the wiring between noise filter
CN6, noise filter CN2, transformer box, and control board CNAC.
Confirm that the wiring between noise filter TB23 and INV board
SC-L3 is put through CT3.
(4) Blown fuse Check F01 on the control board, F4, and F5 for a blown fuse.
->If a blown fuse is found, check for a short-circuiting or earth fault
of the actuator.
(5) CT3 failure Replace the inverter if this problem is detected after the compres-
sor has gone into operation.
(6) Control board failure Replace the control board if none of the above is causing the
problem.