Ze Testing Dilemma

[Sharpend]

Ah but on a LIM EICR do you charge LIM prices!

Most drive by EICR's charge a drive by price!

 

[apprentice87]

The supply i saw with a Ze of .52 or whatever it was, was a western power one, and tncs it was too. I knew full well it was a problem with the service cable, cos the phase with the high reading [the others were about.28] is the same phase [L2] that feeds my house service cable that is about 6 feet further down the LV main in the street. [House had a sensible reading]

Turns out that the DNO jointers had forgotten to tighten the screws in the cutout they had installed a few weeks before....

Lesson, never take anything for granted, check all three phases, and do not think the DNO will have checked it properly themselves, they are just interested in going home!!!

john..

 

[batty]

Im a bit lost on this post, you talk of not disconnecting the main earth to carry out a Ze because you need to turn off the supply. Don't you turn off the supply to do insulation resistance tests, ring continuity tests ect so whats the problem or do you put lim on everything and just carry out a visual inspection. 

You may be able to do this on a domestic but a commercial or industrial installation that has multiple distribution boards if you disconnect the main earth you could come to a sticky end. 

 

[binky]

granted, you need to assess each situation, and for large commercial installations I would be inclined to check earth leakage first.