Electrical Insulation Resistance Test

The measured value is then compared with minimum values stated in the standard in order to verify that there is not a breakdown of insulation caused by damage to cables and other component parts of a circuit.

Electrical insulation resistance test.

The measurement of insulation resistance is a common routine test performed on all types of electrical wires and cables. Insulation resistance is temperature sensitive. Developed early in the 20th century the insulation resistance ir test is the oldest and most widely used test for assessing the quality of insulation. 230v to measure insulation resistance in ohm s.

For good insulation the resistance usually reads in the megohm range. Insulation resistance testing or megger testing as it is more commonly known does what it says on the tin. The insulation resistance test consists in measuring the insulation resistance of a device under test while phase and neutral are short circuited together. Megger mit1020 10 kv insulation resistance testers are all designed specifically to assist the user with the testing and maintenance of high voltage equipment.

The insulation resistance test is an electrical test which uses a certain type and level of voltage 500v d c. The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. This test is to measure the total resistance of a product s insulation by applying a voltage of 500 v 1000 v for low voltage systems. A common rule of thumb is insulation resistance changes by a factor of two for each 10 degrc change.

The purpose of insulation is to prevent the flow of electric current between points of different potential in an electrical system. The measured resistance indicates the condition of the insulation between two conductive parts. When temperature increases insulation resistance decreases and vice versa. An infinite resistance would be the perfect result but no insulator is perfect so the higher the reading the better.

Recommended test voltages for routine maintenance insulation resistance tests of equipment rated to 4 160v and above. It tests the resistance of the insulation of all live parts in electrical circuits. Second the range of a megohmmeter is in megohms as its name implies instead of ohms as in a multimeter. To prevent problems with your electrical equipment due to failure of insulation we recommend insulation tests be conducted regularly.

For low voltage installations i e. The insulation resistance test is the second test required by the electrical safety testing standards. As a production test this test is often used as a customer acceptance test with minimum insulation resistance per unit length often specified by the customer. The acceptable value of resistance for a product to pass an insulation resistance test is relative.

So to compare new readings with previous ones you ll have to correct your readings to some base temperature. The megger insulation tester is essentially a high range resistance meter ohmmeter with a built in direct current generator.