|
Inverter Duty Motors
Machine
tools and process equipment can perform better if the speed of the prime
mover can be controlled. This requirement leads to use of Variable Frequency
Inverters or Drives, popularly known as VFDs in combination with the
electric motors. It is advisable to use Inverted Rated motors while
controlling the motor through VFDs. Invert Rated Insulation protects
the motor from voltage spikes and surges generated while operating the
motor with VFDs.
Depending
upon the requirement, motor can be selected. |
(a) |
Where
speed of the motor is to be reduced approximately up to 50% of the rated
speed, an integral (directly driven) fan mounted on the motor shaft
provides sufficient cooling (IC41 cooling). Hence only insulation system
becomes important which provides protection against voltage spikes and
surges. |
(b) |
Where
the speed of the motor to be reduced further the integral fan mounted
on the motor shaft becomes inactive OR when the speed of the motor is
to be increased with a frequency above 60 Hz, the integral fan overloads
the motor. In such a situation, it becomes very important to provide
cooling by a separately powered fan servo ventilation (IC 46 cooling)
Servi ventilation (IC 46 cooling) is available from frame size 71 to
225M. |
|
|
(C) |
When
the motors are to be used in synchronization, positioning or similar
applications. "ELCEN" motors available with rotary optical
encoders. The criteria for selection of cooling system remains as described
earlier. Depending upon the speed, either integral cooling fan or servo
ventilated cooling can be selected. As a standard 1024PPR incremental
encoder, with 4.75V to 26.8V wutg short circuit push-pull output and
RS422 functionality at 5V ioeratuib, how ever if application demands,
either incremental or absolute encoder can be supplied fitted with the
motor.
Servo Ventilated
motors, encoder fitted motors with or without servo ventilation are
longer then the standard motors. Confirm the lenght at the time of selection. |
|
