Signing Off On Diy

[Essex1]

Very much doubt it.

Oh yes mate. I was there when I saw them.

 

[leesparkykent]

napit and stroma offer third party certification to their members.

 

[Gkinghrn]

I would find it highly unlikely that the RCD would ever trip with a lamp blowing.

unlikely or not it happens .. Seen it enough times on different installs .. Sometimes it does sometimes it doesn't..

 

[Sidewinder]

So, what is the fault path that causes an RCD to trip when a load such as a lamp with no physical connection to earth fails?

 

[Gkinghrn]

So, what is the fault path that causes an RCD to trip when a load such as a lamp with no physical connection to earth fails?

i will let the professionals debate that... I've witnessed it .. All I know is it happens..

 

[Sidewinder]

An RCD, or an MCB?

 

[Lurch]

Here was me trying to get the DIYer to trip himself up and so called electricians fall into the trap as well!

i will let the professionals debate that... I've witnessed it .. All I know is it happens..

You haven't.

 

[Essex1]

Gas-arc?

 

[Apache]

Yes it would be using an existing lighting circuit.

It does have RCD protection on a board for the lighting circuit on that 1 floor.

No not a bathroom it's a bedroom .. With a unboarded loft above it which makes access easy. Hence why I even considered doing it myself. I assume work like this has to be certified to meet local authority rules these days..

Then it is perfectly legal for you to do the work yourself - you don't need to notify anyone.

The sparks on here end up dealing with the DIYers who mess things up. My view is it gives them a very negative attitude towards DIY work.

I'm a DIYer myself and I enjoy doing electrical work in my own home (I ended up a part owner of an electrical forum, and did have more posts than anyone else for a while!). I honestly believe that if someone came along afterwards they could not tell my work from that of a proper electrician. I take care, look up what I don't know, and do it properly.

The law allows DIYers to do such things. If you are competent and have a good attention to detail then I would just get on with it.

 

[Essex1]

Groundhog Day?

 

[Gkinghrn]

Here was me trying to get the DIYer to trip himself up and so called electricians fall into the trap as well!You haven't.

your diyer never said he was a professional so fail to see why you want to trip him up .... Seems unhelpful... Suspect I got the views I can work with . Thank you everyone who responded ..

 

[Essex1]

Just be careful mate and if you are not sure of anything. Call someone in. Underneath all the unhelpfulness and sarcasm is a bunch of forum members that do not want to see anyone hurt.

 

[Doc Hudson]

Hello Gordon, to perhaps try give a bit more perspective, there are three aspects requiring signatures on an electrical installation certificate, (1) design (2) construction & installation (3) inspection and testing. A sample certificate page from one of the guidance books is shown. {note there are other pages that require a lot of test results about the circuit and the supply characteristics also to be written}



Larger companies working on bigger jobs may use different employees or subcontractors for different parts of the work. Thus multiple signatures. On most domestic work it is a single person from a single company who signs for everything, (so there is a shorter single signatory certificate). Whoever signs the bit of paper they give you is leaving you with some written evidence that they declare the work complies with BS7671 and is safe. Should something unforeseen happen in the future and someone gets seriously injured due to the work it does leave a bit of a large liability with the person who's signed your certificate. 

Some electricians may willingly take the gamble and the money and drive off onto the sunset. Others will not take any risk at all. Some may be willing to use a full three signature certificate and only sign the inspection & testing part, but you then have to decide what to do about design & construction. The EICR others have mentioned is not a certificate, it is an inspection report, that purely gives a satisfactory or unsatisfactory evaluation of an installation with ref to the currently wiring regulations. An  EICR should not be used for new or alteration work, it is intended for an inspection of an existing installation after it has been in use for a period of time. 10 years for the average domestic dwelling.

It is rather like an insurance premium, if someone is willing to take the risk of signing for work they have not done, they would probably raise their costs for the signed work to be even more than if they had done all the work in the first place. Which then means it is not so cost effective for you to have done any of it anyway. But as Apache says a vast amount of DIY electrical work goes on every day without any certificates or proper testing, homeowners take the full  risk and gamble and live to see another day. 

Doc H.

 

[Rob_the_rich]

So, what is the fault path that causes an RCD to trip when a load such as a lamp with no physical connection to earth fails?

If there was a leakage current neutral to earth which under normal loads would not trip the rcd, if an arc forms during the blowing of a filament, high currents occur and any leakage current might increase past the tripping current of an RCD. Would this do it?

Just be careful mate and if you are not sure of anything. Call someone in. Underneath all the unhelpfulness and sarcasm is a bunch of forum members that do not want to see anyone hurt.

+1

 

[Lurch]

If there was a leakage current neutral to earth which under normal loads would not trip the rcd, if an arc forms during the blowing of a filament, high currents occur and any leakage current might increase past the tripping current of an RCD. Would this do it?

Theoretically possible, highly unlikely, and even less likely that anyone has seen this happen hundreds of times, definitely not be a common occurrence.

 

[Apache]

Theoretically possible, highly unlikely, and even less likely that anyone has seen this happen hundreds of times, definitely not be a common occurrence.

In our old house the MCB always tripped when a lamp blew.

Never had one go in my current house.

The only time the RCD tripped was when I cut through a live cable with VDE cutters. My wife came home early and turned the breaker on. Safe isolation people!!!

 

[Rob_the_rich]

After safe isolation of a circuit (mcb), cutting a cable will sometimes trip an rcd. I haven't worked that one out.

 

[Lurch]

After safe isolation of a circuit (mcb), cutting a cutting a cable will sometimes trip an rcd. I haven't worked that one out.

Measure the voltage on the N-E.

 

[Rob_the_rich]

Theoretically possible, highly unlikely, and even less likely that anyone has seen this happen hundreds of times, definitely not be a common occurrence.

would induced currents to the bare cpc in t&e under arcing conditions be enough to trip it?

Measure the voltage on the N-E.

Yeah that would explain the tripping on cutting, so it couldn't have been "safe" isolation then.

 

[Doc Hudson]

After safe isolation of a circuit (mcb), cutting a cable will sometimes trip an rcd. I haven't worked that one out.

Where an RCD is protecting multiple MCB's if one MCB is turned off because you are working on that circuit, this only disconnects the Live. The neutral bar common to all the other MCB's sharing that RCD is still connected, so cutting with the pliers makes a N-E connection allowing current from anyone of the other MCB's still energised to imbalance the RCD. You need to disconnect the N from the CU as well as turning off the MCB, or turn off every MCB supplied by that RCD.

Doc H.