Mitsubishi Electric FR-E700 Basic Instruction Manual page 111

Causes and corrective actions
Operation panel
E.OV2
indication
Name
Regenerative overvoltage trip during constant speed
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the specified value,
Description 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.
1. Check for sudden load change.
Check point
2. Check that the setting of Pr. 22 Stall prevention operation level is not too small.
1. Keep load stable.
Check that regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886) is used. (
Corrective action
of the Instruction Manual (applied)).
Use the brake resistor, brake unit or power regeneration common converter (FR-CV) as required.
2. Set the Pr.22 Stall prevention operation level correctly.
Operation panel
E.OV3
indication
Name Regenerative overvoltage trip during deceleration or stop
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the specified value,
Description
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.
Increase the deceleration time. (Set the deceleration time which matches the moment of inertia of the load)
Longer the brake cycle.
Corrective action
Use regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886). (
Manual (applied)).
Use the brake resistor, brake unit or power regeneration common converter (FR-CV) as required.
Operation panel
E.THT
indication
Name
Inverter overload trip (electronic thermal relay function)
If the temperature of the output transistor element exceeds the protection level under the condition that a current not
Description
less than the rated inverter current flows and overcurrent trip does not occur (230% or less), the electronic thermal
relay activates to stop the inverter output. (Overload capacity 150% 60s, 200% 3s)
1. Check that acceleration/deceleration time is not too short.
2. Check that torque boost setting is not too large (small).
Check point
3. Check that load pattern selection setting is appropriate for the load pattern of the using machine.
4. Check the motor for use under overload.
5. Check for too high surrounding air temperature.
1. Increase acceleration/deceleration time.
2. Adjust the torque boost setting.
Corrective action
3. Set the load pattern selection setting according to the load pattern of the using machine.
4. Reduce the load weight.
5. Set the surrounding air temperature to within the specifications.
Operation panel
E.THM
indication
Motor overload trip (electronic thermal relay function) ∗1
Name
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 integrated value reaches
85% of the Pr. 9 Electronic thermal O/L relay setting and the protection circuit is activated to stop the inverter output
Description
when the integrated value 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.(
Check point
Instruction Manual (applied)).
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.
Corrective action
3. Check that stall prevention operation setting is correct. (
(applied)).
∗1
Resetting the inverter initializes the internal thermal integrated data of the electronic thermal relay function.
102
FR-PU04
Stedy Spd OV
FR-PU07
FR-PU04
OV During Dec
FR-PU07
FR-PU04
Inv. Overload
FR-PU07
FR-PU04
Motor Ovrload
FR-PU07
Refer to the chapter 4 of the Instruction
Refer to the chapter 4 of the
Refer to the chapter 4 of the Instruction Manual
Refer to the chapter 4