68
Causes and corrective actions
*3
Resetting the inverter initializes the internal thermal integrated data of the electronic thermal relay function.
Operation Panel
Indication
E.OV2
FR-PU04
Stedy Spd OV
Name
Regenerative overvoltage shut-off during constant speed
Description
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 point
Check for sudden load change.
Corrective action
· Keep load stable.
· Use the brake unit or power regeneration common converter (FR-CV) as required.
Operation Panel
Indication
E.OV3
FR-PU04
OV During Dec
Name
Regenerative overvoltage shut-off during deceleration or stop
Description
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 point
Check for sudden speed reduction.
Corrective action
· Increase the deceleration time. (Set the deceleration time which matches the inertia of moment
of the load)
· Decrease the braking duty.
· Use the brake unit or power regeneration common converter (FR-CV) as required.
Operation Panel
Indication
E.THT
FR-PU04
Inv. Overload
Name
Inverter overload shut-off (electronic thermal relay function)
*3
Description
If a current not less than 110%
*2
of the rated output current flows and overcurrent shut-off does not
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%
*2
60s)
Check point
Check the motor for use under overload.
Corrective action
Reduce the load weight.
*2
120% when LD is selected
Operation Panel
Indication
E.THM
FR-PU04
Motor Ovrload
Name
Motor overload shut-off (electronic thermal relay function)
*3
Description
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.
Check point
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 the Instruction
Manual (applied).)
3. Check that stall prevention operation setting is correct.
Corrective action
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 the Instruction Manual (applied).)
Summary of Contents for FR-F700 Series
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