C390-93

Scope

1.1
This Standard specifies the test methods to be used in measuring the
energy efficiency of three-phase induction motors in support of a
consumer/user information program.
The method of determining and marking the nominal efficiency values are
also specified.

1.2
This Standard applies to three-phase induction motors rated 0.746 kW at
1 BOO r/min (or equivalent*) and greater.
* An equivalent motor is a motor with the same torque output but wfth
different kilowatt output and speed. Torque varies as kilowatts per
revolutions per minute.

1.3
The test methods detailed in this Standard for three-phase induction
motors are segregated in relation to specific kilowatt ratings according
to the following:

Motor Test Methods

0.746 to 37.5 kWat 1800 (1)
r/min or equivalent

Over 37.5 to 150 kWat 1800 (1) or (2)
r/min or equivalent*

Over 150 kW at (1). (2), or (3)
1800 r/min or equivalent*

*An equivalent motor is a motor with the same torque output but wfth
different kilowatt output and speed. Torque varies as kilowatts per
revolutions per minute.

1.4
This Standard does not apply to liquid-filled motors such as submersible
motors.