Are we required to fill out testing certificates when maintenance team modify's wiring

Have the alterations been tested? If so why not record them, If not why is it in service?

Yes

If you are working to BS7671 or alternatively a national standard of a civilsed country then yes it is probably mandated by such that relevant tests and recodings are made.

If you are working for a decent firm then they should have it in their own standard anyway.

Question - what are the benefits and the pitfalls of doing so or not doing so?

You need to have a means of ensuring the new work is safe, and that any change has not made the existing wiring dangerous.

You should ask what happens if there is an accident, and someone says 'Carlo, can you demonstrate that socket was safe when it was installed?'

There is no need to test the whole system, just the bits that are changed, and where it connects in, Only if the checks find something serious like phase neutral reversal or no earth, would you need to look at the original wiring in more detail.

if it was a single socket outlet, then nothing more than a flick with a meter for an  "R2" style test to verify earthing and a  plug in tester  to verify L-N polarity would probably cover the essentials.  Detailed calculation is not always required for small changes,  so long as cables are sensibly sized- voltage drop is more likely to annoy than kill someone.

It is only a matter of choice  you decide to fill out a full EIC style certificate, or just a local system that records what was done by whom, and that the agreed tests were performed - I presume folk are only making changes that are requested, so there is already an audit trail of job cards or work orders or whatever - a small change to this may be all that is needed.

on one of our production machines

Is this work in scope of BS 7671 (wiring regs) or some more specific equipment/machinery standard?


   - Andy.