Notes On The Application - Toshiba TOSVERT VF-S11 Instruction Manual

1.4

Notes on the application

1.4.1
When the VF-S11 and the motor are used in conjunction, pay attention to the following items.
1
Use an inverter that conforms to the specifications of power supply and three-phase induction motor be-
ing used. If the inverter being used does not conform to those specifications, not only will the three-phase
Mandatory induction motor not rotate correctly, but it may cause serious accidents through overheating and fire.
Comparisons with commercial power operation.
Operation in the low-speed area
Adjusting the overload protection level
High speed operation at and above 60Hz
Method of lubricating load mechanisms
Motors
The VF-S11 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.
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.
To carry out low-speed operation continuously at the rated torque, we recommend to use a "VF motor"
or a "Gold motor" designed for use with an inverter. When operating in conjunction with a "VF motor",
you must change the inverter's motor overload protection level to VF motor use (
The VF-S11 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.
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.
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.
Warning
A-16
E6581158
).