Notes On The Application - Toshiba Q9 Plus Bypass ASD Installation & Operation Manual

1.4

Notes on the application

1.4.1 Motors
When this inverter and the motor are used in conjunction, pay attention to the following items.
Use an inverter that conforms to the specifications of power supply and three-phase induction motor
being operated. If the inverter being used does not conform to those specifications, not only will the
three-phase induction motor not rotate correctly, but it may cause serious accidents through overheating
Mandatory
and fire.
action
Comparisons with commercial power operation
This inverter employs the sinusoidal PWM system. However, the output voltage and output current are
not perfect sine waves, they have a distorted wave that is close to sinusoidal waveform. This is why
compared to operation with a commercial power there will be a slight increase in motor 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.
To carry out low-speed operation continuously at the rated torque, we recommend to use a inverter
rated motor or a forced cooled motor designed for use with an inverter. When operating in conjunction
with an inverter rated motor, you must change the inverter's motor overload protection level  to VF
motor use.
Adjusting the overload protection level
This 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 it must be adjusted in line
with the rated current of the 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
this will exceed the motor's mechanical strength limits and the bearing limits so 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
lubricating effect. Check with the manufacturer of the reduction gear to find out about operable gearing
area.
Caution
A-21
E6581611
1