Routine tests

The primary purpose of the routine test is to insure freedom from electrical and mechanical defects, and to demonstrate by means of key tests the similarity of the motor to a "standard" motor of the same design. The "standard" motor is an imaginary motor whose performance characteristics would agree exactly with the expected performance predictions.

Depending on the size of the motor, some or all of the following tests could constitute routine tests:

• Winding resistance measurement

• No-load running current and power

• High-potential test

• Locked-rotor test

• Air-gap measurement

• Direction of rotation and phase sequence

• Current balance

• Insulation resistance measurement

• Bearing temperature rise

• Magnetic center at no-load

• Shaft voltages

• Noise

• Vibration

NEMA MG1 includes the first three tests for all motors, and the fourth test for medium motors only.

Prototype tests

The purpose of a prototype test is to evaluate all the performance characteristics of the motor. This test consists of the following tests in addition to the routine tests:

• No-load saturation characteristic

• Locked rotor saturation characteristic

• Locked rotor torque and current

• Loss measurement including stray load loss

• Determination or measurement of efficiency

• Temperature rise determination

• Surge withstand test