Mitsubishi Electric 700 Series Instruction Manual page 204

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)
Check that acceleration/deceleration time is not too short.
Check that torque boost setting is not too large (small).
Check point Check that load pattern selection setting is appropriate for the load pattern of the using machine.
Check the motor for use under overload.
Check for too high surrounding air temperature.
Increase acceleration/deceleration time.
Adjust the torque boost setting.
Corrective action Set the load pattern selection setting according to the load pattern of the using machine.
Reduce the load weight.
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
Description
Electronic thermal O/L relay setting and the protection circuit is activated to stop the inverter output 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.
Check the motor for use under overload.
Check point
Check that the setting of Pr. 71 Applied motor for motor selection is correct. (Refer to page 125).
Check that stall prevention operation setting is correct.
Reduce the load weight.
Corrective action For a constant-torque motor, set the constant-torque motor in Pr. 71 Applied motor.
Check that stall prevention operation setting is correct. (Refer to page 101).
∗1
Resetting the inverter initializes the internal thermal integrated data of the electronic thermal relay function.
Operation panel
E.FIN
indication
Name
Heatsink overheat
If the heatsink overheats, the temperature sensor is actuated and the inverter trips.
Description
FIN signal is output through FL remote communication when the temperature rises to 85% of the heatsink overheat
protection temperature. (Refer to page 60)
Check for too high surrounding air temperature.
Check for heatsink clogging.
Check point
Check that the cooling fan is not stopped (Check that
Set the surrounding air temperature to within the specifications.
Corrective action Clean the heatsink.
Replace the cooling fan.
Operation panel
E.ILF
indication
Name Input phase loss
Inverter trips when function valid setting (=1) is selected in Pr. 872 Input phase loss protection selection and one phase of
Description the three phase power input is lost. (Refer to page 160).
It may function if phase-to-phase voltage of the three-phase power input becomes largely unbalanced.
Check for a break in the cable for the three-phase power supply input.
Check point
Check that phase-to-phase voltage of the three-phase power input is not largely unbalanced.
Wire the cables properly.
Repair a break portion in the cable.
Corrective action
Check the Pr. 872 Input phase loss protection selection setting.
Set Pr. 872 = "0" (without input phase loss protection) when three-phase input voltage is largely unbalanced.
Causes and corrective actions
is not displayed on the operation panel).
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