Overheat protection of the motor by the inverter (Pr. 9)
4.2 Overheat protection of the motor by the inverter (Pr. 9)
Set the rated motor current in Pr. 9 Electronic thermal O/L relay to protect the motor from overheat.
Electronic thermal O/L relay
Refer to page 150 for the rated inverter current value.
The minimum setting increments are 0.01A for the 55K or lower and 0.1A for the 75K or more.
Performing IPM parameter initialization changes the settings. (Refer to page 43)
Change the Pr. 9 Electronic thermal O/L relay setting to 2.0A according to the motor rated current.
Screen at power-ON
The monitor display appears.
Electronic thermal O/L relay) appears.
the set value to
· 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 thermal relay function will be deteriorated. In this case, use an external thermal relay.
· A special motor cannot be protected by the electronic thermal relay function. Use an external thermal relay.
· PTC thermistor output built-in the motor can be input to the PTC signal (AU terminal). For details, refer to Chapter 4 of
Instruction Manual (Applied).
to choose the PU
to choose the parameter
to show the present
(2.1A for FR-740P-0.75K)
, you can read another parameter.
to show the setting again.
twice to show the next parameter.
0 to 500A
55K or lower
0 to 3600A
75K or higher
PU indicator is lit.
Parameter setting complete!!
Set the rated motor current.
The parameter number
read previously appears.
Refer to page
150 for initial
value of the