Digital Megger Connections 'G'

[Paul583]

Hi, I have a Digital megger and can't recall the purpose or how to use the 'G'for ground connection on the meter.

The other sockets on the meter are L, E2 and E used for 500 and 1000 volts. L being common.

Any instruction on how to use and understand this 'G' socket would be appreciated, as the manual relates to it as the 'protection circle'. But I don't know what that means.

 

[busbar]

You have described the guard terminal. Connected to a metallic ring placed over the outer surface of an apparatus bushing, it will cancel/offset leakage current over the bushing surface, or in a multiconductor cable, tied to one or more conductors to “exclude” them from influencing the measurement. Biddle/AVO/Meggger sells a booklet, “A Stitch in Time,” or AEMC has a terse version

http://www.aemc.com/techinfo/techworkbooks/megohmmeters/tech_megohm.pdf

 

[busbar]

Also page 14+ at

http://assets.fluke.com/manuals/1550b___umeng0000.pdf