Delta MH300 Series - Page 740

Chapter 14 Fault CodesMH300
14-13
ID No. Display Fault Name Description
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,
motor runs freely, and the display shows an ovn
error.
Action and Reset
Action condition
230V series: 410 V
DC
460V series: 820 V
DC
Action time Immediately act when DC bus voltage is higher than the level.
Fault treatment parameter N/A
Reset method Manual reset
Reset condition
Reset only when DC bus voltage is lower than 90% of the over-voltage
level.
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 the drive with a larger capacity model.
4. Adjust braking level (Pr.07-01 or the bolt position of the brake unit).
The setting for stall prevention
level is smaller than no-load
current.
The setting for stall prevention level 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
in the same
power system, the input voltage may surge
abnormally in a short time. In
this case, install an AC reactor.
Motor ground fault
The ground short circuit current
charges the capacitor in the main circuit
through the power. Check if there 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.