Product Manual

-12-
Efficiency and Economics
When selecting a motor for a particular application, both its capital cost
and the cost of energy for operation should be considered.
With today’s EISA mandates that went into affect on Dec. 19, 2010, we
have little choice in selecting the efficiency of the motor, especially if the
motor is a 140 frame motor or higher and rated over 1 HP. There are no
EISA mandates today for 1- Phase motors.
Electrical Supply Distribution System
The electrical supply distribution system must supply the correct voltage
and have sufficient capacity to start and operate the motor load.
Voltage and Frequency
- Motors are available in standard voltage ranges:
- Single-phase motors are rated for 120/240 volts @ 60 Hz
- Three-phase motors up to 100 HP are available for 208-230/460 or
575 volts @ 60 Hz.
- 125 HP and up – 460, 575, 2400 or 4160 volts @ 60 Hz
- Other voltages and frequencies can be ordered to meet special
requirements
- Single-phase and three-phase motors are designed to operate
successfully with voltage variations of +/- 10%.
- Phase unbalance must be less than 1% for proper motor operation.
Phase unbalance leads to excessive temperature rise and a rise to
the full load amps of the motor.
- Frequency variation of up to 5% is permitted for normal motor
operation. Motor speed varies directly with the frequency of the
power supply.