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4.21 PU/FF Troubleshooting
4.21.1 Digital display output
4.21.2 Description
▪ 1PU/FF indicates fan module A protection.
▪ 2PU /FF indicates fan module B protection.
▪ When PU error occurs 10 times in 120 minutes, FF will display, a manual system restart is required before the system
can resume operation.
▪ All units stop running.
▪ Error code is only displayed on the main PCB and user interface.
4.21.3 Possible causes
▪ Switch SW1 incorrectly set.
▪ Power or communication wires not connected properly.
▪ Fan motor blocked or has failed.
▪ Power supply abnormal.
▪ AC filter board damaged.
▪ Fan module damaged.
▪ Inverter module PCB damaged.