Scribd
Upload
42 views2 pages

DC Motor Megger Testing Guide

The document provides instructions for testing a DC motor using a megger tester. It describes removing power from the motor, setting it on an insulated surface, connecting the megger leads to the motor, and taking multiple readings while rotating the motor to test different windings. The higher the meg ohm reading, the better insulated the motor wiring.

Uploaded by

Khai Nguyen
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
42 views2 pages

DC Motor Megger Testing Guide

The document provides instructions for testing a DC motor using a megger tester. It describes removing power from the motor, setting it on an insulated surface, connecting the megger leads to the motor, and taking multiple readings while rotating the motor to test different windings. The higher the meg ohm reading, the better insulated the motor wiring.

Uploaded by

Khai Nguyen
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
You are on page 1/ 2

https://www.hunker.

com/13414371/how-to-megger-a-dc-motor

How to Megger a DC Motor


By G . K . B A Y NE





Testing a DC (direct current) motor may take more than just a simple volt ohmmeter.
Sometimes the problem with the DC motor may won't be apparent until it is under
operation. In cases such, a meg ohm test or megger may be required. The megger
tester uses a high voltage, generally in the 1000 to 10,000 volt range to identify
insulation leakage in motor coils and adjacent wiring. By following a basic setup you
can test a DC motor using this high voltage testing device.

Step 1

Remove all electrical power from the DC motor. You will also want to remove all
electrical terminations from the power source that feeds the motor. Some DC motor
controllers can either give false readings or become damaged by the reversal of
current flow into the control mechanism of the high testing voltage.
VIDEO OF THE DAY

0 seconds of 2 minutes, 27 secondsVolume 0%


Loading ad

Step 2
Set the DC motor on an insulated pad or piece of wood so the frame is not in contact
with any metal surface. If there is a short in the motor wiring and the frame of the
motor is in contact with a conductive surface, the escaping voltage can travel to the
nearest ground path. This pathway may include yourself touching the metal table or
motor frame itself.

Step 3

Connect one lead of the DC motor to the megger probe and the other lead from the
megger to the frame or metal case of the DC motor. Press the power button on the
megger or turn the hand crank. The battery unit will take a few seconds to analyze the
voltage travel and soon a reading should appear on the LCD screen. The higher the
meg ohm reading the better insulated the wiring. The hand crank type of megger will
be instant. The further the needle on the meter is deflected, the least amount of meg
ohms is in the windings or wiring. In other words, on a hand crank type megger, the
further the needle is deflected to the right, the worse the resistance is in the DC motor.

Step 4

Release the push button on the megger or stop the cranking of the meter. Rotate the
end shaft approximately 30 degrees and test the motor again. Perform this procedure a
number of times as most DC motors use a carbon brush and copper commutator to
conduct the electrical power to the armature. This method will ensure that the separate
windings of the armature are being tested.

You might also like