Sparking Earthing Conductor

[Penfield]

Hi,

Whilst carrying out a ZE test I noticed that the earthing conductor sparked when re-inserted into the earth bar. Any ideas/solutions to what may be happening.  The installation was isolated from the main switch onwards. The property is a studio flat within a block above commercial premises. 

 

[Andy™]

probably something coming through extraneous bonding back to MET. could be a sign that someone has an open or faulty neutral

 

[Penfield]

Thanks Andy.

 

[ProDave]

I would have put the clamp meter on it to see how much current it was passing. Also measured the voltage difference when not connected.