If the power supply voltage of the inverter reduces, the control circuit will not operate
properly and will result in decreased motor torque or increased heat generation. To
prevent this, if the power supply voltage reduces below 150V (about 300V for the
400V class), this function stops the inverter output.
When a jumper is not connected across P/+-P1, the undervoltage protective function
Check for start of large-capacity motor.
Check that a jumper or DC reactor is connected across terminals P/+-P1.
Check the power supply system equipment such as power supply.
Connect a jumper or DC reactor across terminals P/+-P1.
If the heatsink overheats, the temperature sensor is actuated to stop the inverter
• Check for too high ambient temperature.
• Check for heatsink clogging.
Set the ambient temperature to within the specifications.
Output side earth (ground) fault overcurrent protection
This function stops the inverter output if an earth (ground) fault overcurrent flows
due to an earth (ground) fault which occurred on the inverter's output side (load
Check for an earth (ground) fault in the motor and connection cable.
Remedy the earth (ground) fault portion.
External thermal relay operation (Note 3)
If the external thermal relay provided for motor overheat protection or the internally
mounted temperature relay in the motor switches on (contacts open), the inverter
output is stopped. If the relay contacts are reset automatically, the inverter will not
restart unless it is reset.
• Check for motor overheating.
• Check that the value of "7" (OH signal) is set correctly in any of Pr. 180 to Pr. 186
(input terminal function selection).
Reduce the load and operating duty.
Note: 3. This function is activated only when OH has been set to any of Pr. 180 to Pr. 186 (input terminal