Toshiba TOSVERT VF-FS1 Series, Instruction Manual

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E6581381
J-4
10
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Magnetic contactor in the secondary circuit
A magnetic contactor may be installed on the secondary side to switch controlled motors or supply
commercial power to the load when the inverter is out of operation.
Notes on wiring
•
Be sure to interlock the magnetic contactor on the secondary side with the power supply to prevent commercial
power from being applied to the inverter output terminals.
•
When installing a magnetic contactor (MC) between the inverter and the motor, avoid turning the magnetic
contactor on or off during operation. Turning the magnetic contactor on or off during operation causes a current
to rush into the inverter which could lead to malfunction.
10.3 Installation of an overload relay
1) The VF-FS1 inverter has an electronic-thermal overload protective function.
In the following cases, however, an overload relay suitable for the adjustment of the motor electronic
thermal protection level (
VJT ) and appropriate to the motor used should be installed between the inverter
and the motor.
•
When using a motor with a current rating different to that of the corresponding Toshiba general-purpose
motor
•
When operating a single motor with an output smaller than that of the applicable standard motor or more
than one motor simultaneously.
2) When using the VF-FS1 inverter to operate a constant-torque motor, such as the Toshiba VF motor, adjust
the protection characteristic of the electronic thermal protection unit (
NO ) to the VF motor use.
3) It is recommended to use a motor with a thermal relay embedded in the motor coil to give sufficient
protection to the motor, especially when it runs in a low-speed range.