Megger
To test insulation resistance with a high-voltage DC tester; also the jobsite name for the tester itself.
Megger is a brand name that became the generic word for an insulation resistance tester and a verb for using one: to megger a cable is to apply a DC test voltage between cores and earth and read the leakage resistance. Some testers generate their test voltage from a hand crank, most from batteries. Electronics, drives and surge devices must be disconnected or shorted out before meggering, because the test voltage can destroy them.
Megger the cable before you terminate it, 1000 volts core to earth and core to core, and write the readings on the sheet.
Disconnect the VFD before you megger a motor cable; the drive's output stage will not survive 1 kV.
Also heard as
- megohmmeter
- IR tester
- insulation tester
Related terms
Insulation resistance test
DC test that applies a high voltage between conductors and earth and reads leakage resistance in megohms.
Hipot
High-potential test: applying a voltage well above working level to prove insulation will not break down.
Ring out
To check continuity and identity of every core of a cable end to end before termination or after a fault.
Same word, different worlds
- Megger in electricians
Insulation resistance tester, and the verb for testing a cable or motor with one.