Step Voltage Test Electric Motors

Step voltage test this dc test is performed to a voltage that a motor typically sees during starting and stopping.

Step voltage test electric motors.

Pump motor or a short control cable may be vital to a process in your plant. Minimum test value of the electric motor is 1 meg ohm 1 mω. The standard procedure is to increase voltage in one minute increments. Match up to the full load.

The voltage is increased in a series of steps and the leakage current is plotted. Ieee 43 2000 ieee 95 2002. A motor placed in storage may or may not work regardless of its physical appearance. As the voltage is.

You should make these periodic tests in the same way each time. This article describes how the machine s insulation is tested and the information. In this test there is a sudden breakdown of the insulation between about 5 6 and 6 5kv and the test is shut down at the end of step 7 at about 6500v because the acceleration in the measured current exceeded the roc limit from step 6 to step 7. The test voltages governed by ieee are reflected in table ii.

Electric motor testing is usuallly the first thing to be sacrificed when cutting back on operational expenses. The first ones ieee 62 1958 eda test basis to the late ones. As the step voltage test progresses every 60 seconds the voltage applied to the insulation system is increased in specific voltage increments which is determined by the user. Step voltage test has become an industrial standard in common use for field testing.

But smart companies understands is that what this means for maintenance programs is billions of dollars of lost revenue through increased motor repair costs downtime and waste in industrial and commercial companies. That is with the same test connections and with the same test voltage applied for the same length of time. From these ones it has evolved a test that implementing the high voltage d c. Dc step voltage test it is typically performed at twice line voltage plus 1000 volts.

For example for a 1500 v ac voltage the equivalent dc voltage to produce the same amount of stress on the insulation would be 1500 x 1 414 or 2121 v dc. The test allows the technician to observe how the insulation system responds to an over voltage stress. When a motor fails it is often difficult to see why it failed just by looking at it. 4160v motor test voltage 9320v.

Therefore if we use dc test voltage we ensure that the dc test voltage is under root 2 or 1 414 times the ac test voltage so the value of the dc voltage is equal to the ac voltage peaks. The dc voltage is applied to all three phases of the winding and raised slowly to a preprogrammed voltage step level and held for a predetermined time period. The leakage current is. Experience is the best teacher in setting up the scheduled periods for your equipment.

The step voltage test is performed upon completi on of a successful polarization index pi test starting at the same voltage used for the pi test. With the motor running check the running amps of the motor using clamp on meter.