Insulation Resistance Test Values

As per ie rules 1956.

Insulation resistance test values.

Insulation resistance test values use these values in the absence of consensus standards dealing with insulation resistance tests. 1k v 1 mω minimum 1kv 1 mω 1kv. Insulation resistance decreases in temperature or moisture. The international electrical testing association neta specification maintenance testing specifications for electrical power distribution equipment and.

The transformer neutral bushing is to be disconnected from earth during the test. Historically many field electricians use the somewhat arbitrary standard of 1 megohm per kv. Also acceptable values of insulation resistance depend upon the equipment you re testing. Hands down without a doubt one of the most universally searched topics on ec m s website from a historical perspective is insulation resistance testing as a result some of our most popular evergreen articles like understanding insulation resistance testing continue to top the charts when it comes to most popular content.

The insulation resistance test is an electrical test which uses a certain type and level of voltage 500v d c. The insulation resistance test is the second test required by the electrical safety testing standards. The insulation resistance test consists in measuring the insulation resistance of a. For low voltage installations i e.

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. One meg ohm rule for ir value for equipment. The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. The measured resistance indicates the condition of the insulation between two conductive parts.

230v to measure insulation resistance in ohm s. Value at 60 seconds after application of the test voltage is referred to as the insulation resistance of the transformer at the test temperature. Test results are dependent on the temperature of the insulating material and the humidity of the surrounding environment at the time of the test. At a pressure of 1000 v applied between each live conductor and earth for a period of one minute the insulation resistance of hv installations shall be at least 1 mega ohm or as specified by the bureau of indian standards.

With a little record keeping and common sense however you can get a good picture of the insulation condition from values that are only relative. Since 80 of electrical maintenance and testing.