Mitsubishi Electric FR-A500 Instruction Manual page 202

Operation Panel
E.OC3
Indication
Name Overcurrent shut-off during deceleration
When the inverter output current reaches or exceeds approximately 200% of the
rated current during deceleration (other than acceleration or constant speed), the
Description
protective circuit is activated to stop the inverter output.
Check for sudden speed reduction.
Check point Check for output short circuit.
Check for too fast operation of motor's mechanical brake.
Increase the deceleration time.
Corrective action
Check mechanical brake operation.
Operation Panel
E.OV1
Indication
Name Regenerative overvoltage shut-off during acceleration
A prealarm (RB indication) occurs if the inverter's internal main circuit DC voltage
reaches or exceeds the specified value, the protective circuit is activated to stop the
Description
inverter output. It may also be activated by a surge voltage generated in the power
supply system.
Check for too slow acceleration. (e,g, during descending acceleration with lifting
Check point
load)
Corrective action Decrease the acceleration time.
Operation Panel
E.OV2
Indication
Name Regenerative overvoltage shut-off during constant speed
A prealarm (RB indication) occurs if the inverter's internal main circuit DC voltage
reaches or exceeds the specified value, the protective circuit is activated to stop the
Description
inverter output. It may also be activated by a surge voltage generated in the power
supply system.
Check point Check for sudden load change.
• Keep load stable.
Corrective action
• Use the brake unit or power regeneration common converter (FR-CV) as required.
Operation Panel
E.OV3
Indication
Name Regenerative overvoltage shut-off during deceleration or stop
A prealarm (RB indication) occurs if the inverter's internal main circuit DC voltage
reaches or exceeds the specified value, the protective circuit is activated to stop the
Description
inverter output. It may also be activated by a surge voltage generated in the power
supply system.
Check point Check for sudden speed reduction.
• Increase the deceleration time. (Set the deceleration time which matches the
inertia moment of the load.)
Corrective action
• Decrease the braking duty.
• Use the brake unit or power regeneration common converter (FR-CV) as required.
PROTECTIVE FUNCTIONS
FR-PU04
FR-PU04
FR-PU04
FR-PU04
193
OC During Dec
OV During Acc
Stedy Spd OV
OV During Dec
5