FAULT
Message Possible cause Action
HW CT B Fail
(F43)
1. Test current loop is broken
2. CTP4 is defective
3. Detection circuit malfunction
1. Check the connection of CNP4 to CNM4
2. Replace CTP4 with new one
3. Check the detection circuit inside the
    inverter
HW CT C Fail
(F44)
1. Test current loop is broken
2. CTP5 is defective
3. Detection circuit malfunction
1. Check the connection of CNP4 to CNM4
2. Replace CTP5 with new one
3. Check the detection circuit inside the
    inverter
1. Large Grid harmonics
2. Switching device is defective
3. Detection circuit malfunction
1. Check the utility waveform. Grid connection
    of inverter need to be far away from
    non-linear load if necessary
2. Check all switching devices in inverter
    stage
3. Check the detection circuit inside the
    inverter
The detection circuit for
synchronal signal malfunction
Check the detection circuit for synchronal
signal inside the inverter
HW AC OCR
(F45)
HW ZC Fail
(F50)
DC Cur. High
(F60, F61,
F70, F71)
1. Switching device in boost
    is defective
2. Driver for boost is defective
3. Input current detection
    circuit  malfunction
1. Check all switching device in boost
2. Check the driver circuit for boost inside
    the inverter
3. Check input current detection circuit
Ext Comm
Fail
(F74)
1. External communication
    unit is idling
2. The communication
    connection is disconnected
1. Check the connection between external
    unit and COMM
2. Check the communication circuit
HW DC RLY
(F76)
1. Driver circuit for relay is
    defective
2. Relay(s) is defective
1. Check the driver circuit for relay
2. Replace the defective relay
Table 7-3 : Fault Message
62
Error message and Trouble Shooting