Inverter-Driven 400V Class Motor; Application To Special Motors; Geared Motor; Synchronous Motor - Mitsubishi Electric FR-A700 Manual

When driving a 400V class motor by the inverter, surge voltages attributable to the wiring constants may occur at the motor
terminals, deteriorating the insulation of the motor. In such a case, consider taking the following measures.
(1) Rectifying the motor insulation
1. Use a "400V class inverter driven insulation-enhanced motor".
Note: The four poles of the Mitsubishi standard motor (SF-JR, SB-JR) have the 400V class inverter driving insulation-
enhanced feature.
2. For the dedicated motor such as the constant-torque motor and low-vibration motor, use the "inverter-driven,
dedicated motor".
(2) Suppressing the surge voltage on the inverter side
Connect a filter on the secondary side of the inverter to suppress a surge voltage so that the terminal voltage of the motor is 850V
or less. When driving by the Mitsubishi inverter, connect an optional surge voltage suppression filter (FR-ASF-H) for the 55K or
less and an optional sine wave filter (MT-BSL, BSC) for the 75K or more on the inverter output side.
Motor with brake
Use the motor with brake having independent power supply for
the brake, connect the brake power supply to the inverter
primary side power and make the inverter output off using the
output stop terminal (MRS) when the brake is applied (motor
stop). Rattle may be heard according to the type of the brake in
the low speed region but it is not a fault.

Pole changing motor

As this motor differs in rated current from the standard motor,
confirm the maximum current of the motor and select the
inverter. Be sure to change the number of poles after the motor
has stopped. If the number of poles is changed during rotation,
the regenerative overvoltage protecion circuit may be activated
to cause an inverter alarm, coasting the motor to a stop.

Submersible motor

Since the motor rated current is larger than that of the standard
motor, make selection of the inverter capacity carefully. In
addition, the wiring distance between the motor and inverter
may become longer, refer to page 87 to perform wiring with a
cable thick enough. Leakage current may flow more than the
land motor, take care when selecting the earth leakage current
breaker.
Explosion-proof motor
To drive an explosion-proof type motor, an explosion-proof test
of the motor and inverter together is necessary. The test is
also necessary when driving an existing explosion-proof
motor.
The inverter is an non-explosion proof structure, install it in a
safety location.
103

Inverter-driven 400V class motor

Application to special motors

Geared motor

The continuous operating rotation range of this motor changes
depending on the lubrication system and maker. Especially in
the case of oil lubrication, continuous operation in the low-
speed range only can cause gear seizure. For fast operation
at higher than 60Hz, please consult the motor maker.

Synchronous motor

This motor is not suitable for applications of large load
variation or impact, where out-of-sync is likely to occur. Please
contact us when using this motor because its starting current
and rated current are greater than those of the standard motor
and will not rotate stably at low speed.

Single phase motor

The single phase motor is not suitable for variable operation
by the inverter.
For the capacitor starting system, the capacitor may be
damaged due to harmonic current flowing to the capacitor.
For the deviation phase starting system and repulsion starting
system, not only output torque is not generated at low speed
but it will result in starting coil burnout due to failure of
centrifugal force switch inside. Replace with a three-phase
motor for use.