Mitsubishi Electric FR-F740 EC Instruction Manual page 108

Overheat protection of the motor by the inverter
NOTES
Protective function by electronic thermal relay function is reset by inverter power reset and
reset signal input. Avoid unnecessary reset and power-off.
When two or more motors are connected to the inverter, they cannot be protected by the
electronic thermal relay function. Install an external thermal relay to each motor.
When the difference between the inverter and motor capacities is large and the setting is
small, the protective characteristics of the electronic over current protection will be deterio-
rated. In this case, use an external thermal relay.
A special motor cannot be protected by the electronic thermal relay function. Use an exter-
nal thermal relay.
PTC thermistor output built-in the motor can be input to the PTC signal (AU terminal).
(For details refer to section 3.3.)
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Operation