Cutler-Hammer - Eaton Canada

Application Considerations
Motor Selection
Careful consideration of the proper motor is
essential to obtain optimum performance from
your drive. Contact your Cutler-Hammer sales
representative or distributor for additional
assistance and/or literature regarding motor
selection and other aspects of drive applications.
1. Your AF93/IS903 drive is designed to be
connected directly to a single, NEMA design
B, three phase AC motor. The motor must be
selected and applied so that the average
operating motor current and horsepower do
not exceed the continuous current and
horsepower ratings of the drive. The
intermittent operating current must not
exceed the intermittent current rating of the
drive.
2. Consider the effect of speed on the cooling
capacity of the motor. As you slow down
some types of motors (such as a Totally
Enclosed Fan Cooled [TEFC]), its internal
fan turns slower which reduces air flow
through the motor. Typically, these types of
motors may overheat if you operate them for
extended periods of time at their rated
torque and a reduced speed (less than 50%
of full speed). Choose a motor that matches
the expected duty, torque range and speed.
Pre-Installation
INSTALLATION
3. Multiple motors may be operated by an
AF93/IS903 drive if:
¥ Total current from all motors does not
exceed the current rating of the AF93/IS903.
¥ Individual motor overload protection is
supplied.
¥ All motors must start and change speed
together.
! Warning
If you configure the drive to operate above 60
Hz, the motor may operate above its nameplate
speed. Personal injury or equipment damage
may exist when you operate the motor and
driven machines above their rated speed. Make
certain that all guards and shields are in place
before operating at any speed. Refer to the
motor manufacturer to verify safe motor speed.
AF93/IS903 Instruction Manual
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