Dead shower, charred cable

[PrinceofDarkness]

Holmslaw: Try directing your posts to directly assisting the O/P, CBX.

If you'd like to 'have a go' at another member here, you ought to have the courage to start your own, separate vitriolic thread.



Lucia.

 

[CBX]

Thanks again for all the replies gents.

I've spoken to an electrician who sounded like he knew what he was talking about, and he's coming to see the job and quote. He talked about looking at the earth bonding too (on water and gas mains) as apparently it's supposed to be 10mm2 and not 6mm2 (I think mines 6mm2 as my house was built in 1986).

Given the original circuit lasted at least 6 years, and the only damage looks to be possibly a bad connection in the first place, I'm leaning towards simply replacing a section of 6mm2 myself. Now I'm a bit more clued up about the situation, I'll keep an eye on it etc. I live by myself and don't take 20 minute showers - obviously in the event of house sale/renting etc I think there's a duty to be open about such issues/or fix beforehand.

I'll see what the sparky quotes/says though and perhaps contrast with a second quote too.

Again, thanks - I appreciate it must be hard to get people posting who don't know their arse from their elbow, and you want to help but don't want them to stick their manhood in the mains due to ignorance.

 

[PrinceofDarkness]

CBX: There's no imperative to upgrade the bonding from 6mm to 10mm on any existing installation if it was installed to a previous set of Regulations - even if it's an early PME installation installed in accordance with the old (statutory) Electricty Supply Regulations.

The time to upgrade the bonding is when the supplier upgrades his supply.


Lucia.

 

[CBX]

CBX: There's no imperative to upgrade the bonding from 6mm to 10mm on any existing installation if it was installed to a previous set of Regulations - even if it's an early PME installation installed in accordance with the old (statutory) Electricty Supply Regulations.

The time to upgrade the bonding is when the supplier upgrades his supply.


Lucia.

Ah interesting. The chap indicated he wouldn't be able to touch the shower circuit if the bonding wasn't 10mm2. I've no idea whether that's regulation now, so again this is the very real benefit of this forum.

I always get multiple quotes in, and whether for building, electricity, gas etc everyone always says different things despite the hugely (over?) regulated industries. Then again, the more you know as a householder, whilst not an expert, you can really gauge the person by what they are telling you.

 

[PrinceofDarkness]

I've no doubt that your electrician was in earnest, CBX, about the upgrading to 10mm main bonding. But he's quite mistaken.

He would of course have to verify that the existing 6mm bonding is safe and sound (after all, we don't want any more loose joints, do we) - but he has no business to upgrade or 'up-size' an existing installation just for the sake of it.

10mm bonding is installed as a matter of course (and sometimes as a matter of habit) for new installations. But I repeat, there's no cause to replace 6mm bonding without good reason.....


Lucia.

 

[CBX]

Oh absolutely - in the event testing showed my installation wasn't properly earthed, then I'd be more than keen to get it sorted (unexpected death at this time doesn't really appeal).

I'll see what he says during the visit, but if he specifcally states upgrading to 10 is a requirement for him to even touch my electrics (earnestly or not), then it will undermine confidence. So thanks for pointing out the facts

 

[PrinceofDarkness]

I can't say that I blame you, CBX, for your apparent scepticism about Registered - or 'qualified sparks'.

The problem with most 'sparks', is that they try to play it safe by relying on the old 'grapevine' - but nevertheless, most of them are genuine in their beliefs - misguided though they might be.........


Lucia.

 

[CBX]

Just a quick one:

Have 60A jb - what is the best way to join the 2 6mm2 ends?

- each end of cable half in joining block, 2 screws each
- meshing the strands together the entire length of the block
- each cable goes entire length of the block, not meshed.

I assume it's the first one, but as this is a serious cable, doesn't hurt to check

Note: whichever, I intend to keep an eye on it especially after a quick test run.

 

[CBX]

Though actually after looking at it a bit more, it looks like the third option would be best and create the least resistance/best joint.

The stands all flatten out and are screwed down tight, if both cables are flattened out on top of each other and tight, then this has to be better than relying on the block itself to conduct the electricity alone.

May be obvious to electrians, but given I know I'm not, I'm taking care and thinking through what I do here

 

[ban-all-sheds]

I'll see what he says during the visit, but if he specifcally states upgrading to 10 is a requirement for him to even touch my electrics (earnestly or not), then it will undermine confidence.

I wouldn't be too hasty in that regard:

131.8 Additions and alterations to an installation

No addition or alteration, temporary or permanent, shall be made to an existing installation, unless it has been ascertained that the rating and the condition of any existing equipment, including that of the distributor, will be adequate for the altered circumstances. Furthermore, the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate.

411 Protective Measure: Automatic Disconnection of Supply (ADS)
411.1 General

Automatic disconnection of supply is a protective measure in which:

(i) basic protection is provided by basic insulation of live parts or by barriers or enclosures, in accordance with Section 416, and

(ii) fault protection is provided by protective earthing, protective equipotential bonding and automatic disconnection in case of a fault, in accordance with Regulations 411.3 to 411.6.

So if you are having work done by an electrician, it's not unreasonable for him to decide that if he is certifying that his work complies with BS 7671:2008 then 131.8 means that he has to ensure that the earthing and bonding complies with BS 7671:2008, not just with whatever an earlier edition of the regulations required at the time it was originally installed.

 

[CBX]

Shower now working fine - thanks for all the advice.

I obviously don't have the kit for any checks aside from a multimeter. Is there any sensible way I can test the earth now that I've changed the pull switch and put in a joint box?