Mitsubishi Electric F700 Instruction Manual page 241

Causes and corrective actions
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
*2 120% when LD is selected
Operation Panel
Indication
Name
Description
Check point
Corrective action
*3 Resetting the inverter initializes the internal thermal integrated data of the electronic thermal relay function.
234
E.OV1
Regenerative overvoltage shutoff during acceleration
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the
specified value, 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 for too slow acceleration. (e.g. during descending acceleration with lifting load)
Decrease the acceleration time.
E.OV2
Regenerative overvoltage shut-off during constant speed
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the
specified value, 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 for sudden load change.
· Keep load stable.
· Use the brake unit or power regeneration common converter (FR-CV) as required.
E.OV3
Regenerative overvoltage shut-off during deceleration or stop
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the
specified value, 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 for sudden speed reduction.
· Increase the deceleration time. (Set the deceleration time which matches the inertia moment of
the load)
· Decrease the braking duty.
· Use the brake unit or power regeneration common converter (FR-CV) as required.
E.THT
Inverter overload shut-off (electronic thermal relay function)
If a current not less than 110%
occur (170% or less), inverse-time characteristics cause the electronic thermal relay to be
activated to stop the inverter output in order to protect the output transistors. (overload immunity
110% 60s)
*2
Check the motor for use under overload.
Reduce the load weight.
E.THM
Motor overload shut-off (electronic thermal relay function)
The electronic thermal relay function in the inverter detects motor overheat due to overload or
reduced cooling capability during constant-speed operation and pre-alarm (TH display) is output
when the temperature reaches 85% of the Pr. 9 Electronic thermal O/L relay setting and the
protection circuit is activated to stop the inverter output when the temperature reaches the
specified value. When running a special motor such as a multi-pole motor or multiple motors,
provide a thermal relay on the inverter output side since such motor(s) cannot be protected by the
electronic thermal relay function.
1. Check the motor for use under overload.
2. Check that the setting of Pr. 71 Applied motor for motor selection is correct. (Refer to page 80.)
3. Check that stall prevention operation setting is correct.
1. Reduce the load weight.
2. For a constant-torque motor, set the constant-torque motor in Pr. 71 Applied motor.
3. Check that stall prevention operation setting is correct. (Refer to page 56.)
FR-PU04 OV During Acc
FR-PU04 Stedy Spd OV
FR-PU04 OV During Dec
FR-PU04 Inv. Overload
of the rated output current flows and overcurrent shut-off does not
*2
FR-PU04 Motor Ovrload
*3
*3