Toshiba VF-S9 manual Notes on the application, Motors, Comparisons with commercial power operation

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E6580757

1.4Notes on the application

1.4.1Motors

When the VF-S9 and the motor are used in conjunction, pay attention to the following items.

Warning

	Use an inverter that conforms to the specifications of the three-phase induction motor and power supply
	being used. If the inverter being used does not conform to those specifications, not only will the three-
Mandatory	phase induction motor not rotate correctly, but it may causes serious accidents through overheating and
	fire.

Comparisons with commercial power operation.

The VF-S9 Inverter employs the sinusoidal PWM system. However, the output voltage and output cur- rent do not assume a precise sine wave, they have a distorted wave that is close to sinusoidal wave- form. This is why compared to operation with a commercial power there will be a slight increase in mo- tor temperature, noise and vibration.

Operation in the low-speed area

When running continuously at low speed in conjunction with a general purpose motor, there may be a decline in that motor's cooling effect. If this happens, operate with the output decreased from rated load.

If you want to run continuously low speed operations at rated torque, please use the VF motor made especially for Toshiba inverter. When operating in conjunction with a VF motor, you must change the

inverter's motor overload protection level to "VF motor use ( )".

Adjusting the overload protection level

The VF-S9 Inverter protects against overloads with its overload detection circuits (electronic thermal). The electronic thermal's reference current is set to the inverter's rated current, so that it must be ad- justed in line with the rated current of the general purpose motor being used in combination.

High speed operation at and above 60Hz

Operating at frequencies greater than 60Hz will increase noise and vibration. There is also a possibility that such operation will exceed the motor's mechanical strength limits and the bearing limits so that you should inquire to the motor's manufacturer about such operation.

Method of lubricating load mechanisms.

Operating an oil-lubricated reduction gear and gear motor in the low-speed areas will worsen the lubri- cating effect. Check with the manufacturer of the reduction gear to find out about operable gearing area.

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