Mitsubishi Electric FR-A700 EC, Instruction Manual

Page: 731 / 826

Troubleshooting Causes and corrective actions
FR-A700 EC 7 - 13
Resetting the inverter initializes the internal thermal integrated data of the electronic thermal
relay function.
When 200 % overload capacity is selected.
Resetting the inverter initializes the internal thermal integrated data of the electronic thermal
relay function.
Operation Panel
Indication
E.THT
FR-PU04
FR-PU07
Inv. Overload
Name
Inverter overload shut-off (electronic thermal relay function)
Description
If a current not less than 150% of the rated output current flows and overcurrent shut-off
does not occur (220% 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 150% 60s)
Check point Check the motor for use under overload.
Corrective action Reduce the load weight.
Operation Panel
Indication
E.THM
FR-PU04
FR-PU07
Motor Overload
Name
Motor overload shut-off (electronic thermal relay function)
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" set-
ting 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
section 6.12.2) and check that the setting of the rated motor current in Pr. 9 is correct.
3) Check that stall prevention operation setting is correct. (Refer to section 6.7.4.)
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 section 6.7.4.)
Operation Panel
Indication
E.FIN
FR-PU04
FR-PU07
H/Sink O/Temp
Name Fin overheat
Description
If the heatsink overheats, the temperature sensor is actuated to stop the inverter output.
The FIN signal can be output when the temperature becomes approximately 85% of the
heatsink overheat protection operation temperature. For the terminal used for the FIN sig-
nal output, assign the function by setting "26" (source logic) or "126" (sink logic) in any of
Pr. 190 to Pr. 196 "Output terminal function selection". (Refer to section 6.14.5.)
Check point
1) Check for too high ambient temperature.
2) Check for heatsink clogging.
3) Check that the cooling fan is stopped. (Check that FN is displayed on the operation
panel.)
Corrective action
1) Set the ambient temperature to within the specifications.
2) Clean the heatsink.
3) Replace the cooling fan.