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What to Know about the Megger Insulation Test

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The Megger insulation test is a test done on insulators to make sure that it maintains its high resistance to current flow. The reason it is called a Megger test by most electricians is because the usual tester used is Megger test equipment. Megger is a trademark and is one of the leading manufacturers of electrical test equipment.

This insulation test is done on electrical insulators to check their integrity. Most insulators may appear fine on visual inspection but contamination, humidity and internal degradation, which are easily missed if you are not inspecting carefully, can cause poor isolation. It may cause harm to personnel and damage to other electrical equipment. The test is done by placing a high electrical voltage on the conductor. While the voltage is applied, the resistance of the insulator is measured. A good insulator should have a resistance of several hundred Megohms. A reading of 1 Megohm or less indicates faulty insulation. During the test, the voltage applied may reach as high as 5 kilovolts depending on the test equipment. Proper isolation and grounding is necessary to prevent electrical shocks or flash overs. 

Having the right equipment for electrical tests is needed to prevent accidents caused by faulty electrical systems. Protec offers test equipment rental to suit your needs.