Chapter 14 Fault Codes and DescriptionsC2000 Plus
ID* Display on LCD Keypad Fault Name Fault Descriptions
9
Over-voltage at
constant speed
(ovn)
DC bus over-voltage at constant speed.
When ovn occurs, the drive closes the gate of the output
immediately, the motor run
s freely, and the display
shows an ovn fault.
Action and Reset
Action condition
230V models: 410 V
DC
460V models: 820 V
DC
575V models: 1116 V
DC
690V models: 1318 V
DC
Action time Act immediately when DC bus voltage is higher than the condition
Fault treatment parameter N/A
Reset method Manual reset
Reset condition Reset only when DC bus voltage is lower than 90% of over-voltage condition
Record Yes
Cause Corrective Actions
Impulsive change of the load
1. Connect brake resistor, brake unit or DC bus to the drive.
2. Reduce the load.
3. Replace to drive with a larger capacity model.
4. Adjust braking level (Pr.07-01 or bolt position of the brake unit).
The setting for stall prevention
condition is smaller than no-load
current
The setting of stall prevention condition should be larger than no-load current
Regenerative voltage of motor
inertia
Use over-voltage stall prevention function (Pr.06-01)
Use a brake unit or DC bus
Power voltage is too high
Check if the input voltage is
within the rated AC motor drive input voltage range,
and check for possible voltage spikes.
ON/OFF switch action of phase-in
capacitor in the same power
system
If the phase-in capacitor or active power supply unit acts
system, the input voltage may surge abnormally in a s
install an AC reactor.
Motor ground fault
The ground short-
circuit current charges the capacitor in the main circuit through
the power. Check if ther
e is ground fault on the motor cable, wiring box and its
internal terminals.
Troubleshoot the ground fault.
Incorrect wiring of brake resistor or
brake unit
Check the wiring of brake resistor or brake unit.
Malfunction caused by
interference
Verify the
wiring of the control circuit and wiring/grounding of the main circuit to
prevent interference.