2-13
Driving 400 V class series motor
• If a thermal relay is installed in the path between the inverter and the motor to protect
the motor from overheating, the thermal relay may malfunction even with a wiring
length shorter than 50 m. In this situation, add an output circuit filter (option) or lower
the carrier frequency (Function code F26).
• If the motor is driven by a PWM-type inverter, surge voltage that is generated by
switching the inverter component may be superimposed on the output voltage and
may be applied to the motor terminals. Particularly if the wiring length is long, the
surge voltage may deteriorate the insulation resistance of the motor. Consider any of
the following measures.
- Use a motor with insulation that withstands the surge voltage. (All Fuji standard
motors feature insulation that withstands the surge voltage.)
- Connect an output circuit filter (option) to the output terminals (secondary circuits)
of the inverter.
- Minimize the wiring length between the inverter and motor (10 to 20 m or less).
DC reactor terminals, P1 and P (+)
1) Remove the jumper bar from terminals P1 and P(+).
2) Connect a DC reactor (option) to terminals P1 and P(+).
• The wiring length should be 10 m or below.
• Do not remove the jumper bar if a DC reactor (DCR) is not going to be used.
• If a converter is connected, you do not need to connect a DC reactor (DCR).
When wiring the inverter to the power supply
that is 500 kVA or more, be sure to connect an optional
DC reactor (DCR).
Otherwise, fire could occur.
DC braking resistor terminals, P(+) and DB
1) Connect a DC braking resistor (option) to terminals P(+) and DB.
2) When using an external braking resistor, arrange the inverter and braking resistor to keep the
wiring length to 5 m or less and twist the two wires or route them together in parallel.
Never insert a DC braking resistor between the terminals P(+) and N(-), P1 and N(-), P(+) and P1,
DB and N(-), or P1 and DB.
Doing so could cause fire.
