C390-93

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 1800 r/min (or equivalent*) and greater. *An equivalent motor is a motor with the same torque output but with 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 kW at 1800 r/min or equivalent* (1) Over 37.5 to 150 kW at 1800 r/min or equivalent* (1) or (2) Over 150 kW at 1800 r/min or equivalent* (1), (2), or (3) * An equivalent motor is a motor with the same torque output but with different kilowatt output and speed. Torque varies as kilowatts per revolutions per minute. 1.4 This Standard does not aply to liquid-filled motors such as submersible motors.