Yaskawa YASNAC PC NC Maintenance Manual - Manual (Page 71)

PC NC Maintenance Manual Chapter 4: Troubleshooting
4-50
AL-11:Main circuit overvoltage
Error Contents The main circuit DC voltage exceeded the overvoltage setting value
(410V).
Detection Methods Output to the control card formatting the main circuit AC voltage sig-
nal [VDET] by the gate driver (7CN-41). If VDET exceeded the main
circuit overvoltage detection level [410V], the current is instanta-
neously intercepted, and the main circuit overvoltage detection signal is
turned ON.
If the main circuit overvoltage detection has been turned ON, the drive
is stopped and the alarm is displayed.
Cause and measures
Cause Measures
Power supply voltage is high. Check the voltage between input terminals.
Power supply voltage is low (regenera-
tive ability decrease by the voltage
reduction). Change the power supply voltage to the value in the speci-
fication value by the transformer tap changer etc.
Power supply open phase and power
failure Normalize the power supply.
Motor code improper selection Confirm control parameter (C1-25) setting and refer to the
setting list.
Control parameter setting is defective. Refer to the setting list for the control parameters.
The converter selection is defective. Perform a proper selection (related to servo capacity).
The reactor selection is defective. Perform a proper selection (corresponded to the converter
capacity).
Control card fault Exchange unit (exchange control card)
Converter (MR5) error Exchange unit (exchange converter)