Help needed

[russellellwood]

I am due to have my fuse box replaced next week, for a consumer unit, before it is replaced I am in the process of removing the old wiring from the old heaters. When removing wires from the fuse box today I knocked the incoming earth wire and saw a spark between the wire and the fuse box case. I believe i have a TN-C-S supply. What would of caused this spark. I check tightened everything in the fuse box. Wiggled the wire again and it happened again. Would like to know what could be causing this as when the new consumer unit is install any work required after testing would be a struggle to finance due to a very tight budget. I have had experience with electrics from growing up and being taught by my dad.

Cheers

Russell

 

[londonboy]

Could be something (usually electronic) leaking some current back down the cpc (earth).

Just make sure its back in its terminal and tight.
Your spark will highlight any faults when he tests.

 

[GaryMo]

How old is the existing wiring? It's not rubber is it?

 

[ban-all-sheds]

when the new consumer unit is install any work required after testing would be a struggle to finance due to a very tight budget.

If you've got an electrician planning to install a CU without doing tests first then one of you is taking a risk.