Mitsubishi FR - S500 Instruction Manual page 148

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
*1. Resetting the inverter initializes the internal heat integrating data of the
electronic overcurrent protection.
Operation Panel Indication
Name
Description
Check point
Corrective action
OV3
Regenerative overvoltage cut-off during deceleration or stop
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 for sudden speed reduction.
Increase the deceleration time. (Set the deceleration time which
matches the inertia moment of the load)
Decrease the braking duty.
Install a power factor improving reactor.
THM
Motor overload cut-off (electronic thermal overcurrent protection)
(* 1)
The electronic overcurrent protection in the inverter detects motor
overheat due to overload or reduced cooling capability during low-
speed operation to stop the inverter output. When a multi-pole
motor or two or more motors are run, provide a thermal relay in
the output side of the inverter.
Protection from burning due to motor temperature rise
Check the motor for use under overload.
Reduce the load weight.
For the constant-torque motor, change the Pr. 71 setting to the
constant-torque motor setting.
THT
Inverter overload cut-off (electronic thermal overcurrent protection)
(* 1)
If a current of more than 150% of the rated output current flows
and overcurrent shut-off does not occur (200% or less), inverse-
time characteristics cause the electronic overcurrent protection to
be activated to stop the inverter output in order to protect the
output transistors.
Output transistor protection from overheat
Check the motor for use under overload.
Reduce the load weight.
FIN
Fin overheat
If the cooling fin overheats, the overheat sensor is actuated to
stop the inverter output.
Check for too high ambient temperature.
Check for cooling fin clogging.
Set the ambient temperature to within the specifications.
139
FR-PU04 OV During Dec
FR-PU04 Motor Overload
FR-PU04 Inv. Overload
FR-PU04 H/Sink O/Temp