MITSUBISHI ELECTRIC FR-S520E - Manual (Page 172)

162
Errors (Alarms)
Operation Panel Indication OV1 FR-PU04 OV During Acc
Name Regenerative overvoltage shut-off during acceleration
Description
When the main circuit DC voltage in the inverter rises to or above
the specified value due to excessive regenerative energy during
acceleration, the protective circuit is activated to stop the inverter
output. The circuit may also be activated by a surge voltage
produced in the power supply system.
Check point
Check for too slow acceleration. (e.g. during downward
acceleration in vertical lift load)
Corrective action
• Decrease the acceleration time.
• Install a power factor improving reactor.
Operation Panel Indication OV2 FR-PU04 Stedy Spd OV
Name Regenerative overvoltage shut-off during constant speed
Description
When the main circuit DC voltage in the inverter rises to or above
the specified value due to excessive regenerative energy during
constant speed, the protective circuit is activated to stop the inverter
output. The circuit may also be activated by a surge voltage
produced in the power supply system.
Check point Check for sudden load change.
Corrective action
• Keep load stable.
• Install a power factor improving reactor.
Operation Panel Indication OV3 FR-PU04 OV During Dec
Name Regenerative overvoltage shut-off during deceleration or stop
Description
When the main circuit DC voltage in the inverter rises to or above
the specified value due to excessive regenerative energy during
deceleration or stop, the protective circuit is activated to stop the
inverter output. The circuit may also be activated by a surge
voltage produced in the power supply system.
Check point Check for sudden speed reduction.
Corrective action
• Increase the deceleration time. (Set the deceleration time which
matches the moment of inertia of the load)
• Decrease the braking duty.
• Install a power factor improving reactor.