New shower cable

[securespark]

They don't do deep-fried Mars bars in France, do they?

 

[ColJack]

deep fried frogs legs though...

 

[Zambezi]

Yes, I was very surprised that the fuse had not blown after all the melting and arching inside the shower added to the fact that the shower is drawing more than the fuse is rated at.

 

[skenk]

Yes, I was very surprised that the fuse had not blown after all the melting and arching inside the shower added to the fact that the shower is drawing more than the fuse is rated at.

If the sparking was caused by a loose connection there would be no reason for it to draw any more current than in normal operation would there? Yes if it was a short circuit then you would expect the fuse to blow. On 30A fuse wire an 8.5Kw shower will last indefinitely.

They don't do deep-fried Mars bars in France, do they?

No and I would never eat such c*** but I am looking forward to a fish supper when I get back!



*fish and chips to you sassenachs!

 

[ban-all-sheds]

422.4.3

May well prevent the installation of wooden-backed fuse boards. Doesn't mean that you can't add a new circuit to an existing one.

422.4.4?

Ditto.

or 421.7 which re-directs you to 526.5 and may I draw you attention to part (iii) of the same..

526.5 - Every termination and jointin a live of PEN conductor shall be made within one of thefollowing or a combination thereof:

(i) A suitable accessory complying with the appropriate product standard
(ii) An equipment enclosure complying with the appropriate product standard
(iii) An enclosure partially formed or completed with building material which is non-combustible when tested to BS476-4

Might be getting somewhere there, but....

Those Wylexs weren't 100% wood, so they were partially formed with something non-wooden.

I don't suppose for one second that a modern plastic CU would withstand combustibility tests aimed at building materials. Not that I know what they are, but they involve electric furnaces.

I do know this though - give me a blowtorch or a hot wire and I'll have a plastic CU on fire, or melted away, or full of holes a damn sight quicker than I could a wood and bakelite one....

 

[ban-all-sheds]

you must be, who would lie about being in france if they didn't have to...

You do sometimes get tw@s here who think its funny or clever to lie about where they are...

 

[ban-all-sheds]

deep fried frogs legs though...

And jolly nice they are, too....

 

[roundthebend]

Folks

Thanks for so many replies. I think that someone somewhere has added their own anecdote to the thread and this might have caused some confusion - well, it's confused me more.

The CU we have is indeed an old WYLEX. We live in an ex council house which was built around 1970-1975 I think.

It's sunk into the wall and has a removable cover. To remove I just unscrew it at the top and lift off. It reveals about 8 fuse holders that look like this

I don't need to fiddle with fuse wire, I just take that fuse holder apart and put a new fuse in and do it all back up again.

Hope that helps.

I think the best suggestion so far is to put in a new CU but just run the shower circuit from it. That sounds like it wouldn't add a huge extra cost, it would deal with the problem, and it would allow a cost effective improvement to the rest of the circuits at a later date.

How does that sound?

 

[skenk]

You will have to either get the fuseboard replaced or install an additional fuseboard (now called Consumer Unit - CU) for the shower. If you get the fuseboard replaced all circuits will have to be brought up to scratch which will mean extra testing and may mean extra remedial work. If you get an additional CU you will also need an isolator so there is a single point of isolation for the whole installation. Yes, if you get a full size new CU and only put the shower on it at the moment (insignificant extra cost) then you can have the other circuits moved over later. The main bonding and earthing will have to be up to scratch before either option can be done, supplementary bonding may be required for the bathroom if none exists at the moment. Still gonna cost £100's tho even if no bonding upgrading is req'd.

 

[roundthebend]

Update.

I decided that my electrician friend is the professional and this is far too complicated for me to fit into the little time I have. So, rather than try and understand it all and still get him to do it, I just thought I'd let him go ahead.

As far as I know, he has replaced the 6mm sq cable with a 10mm sq cable. He said the 30A fuse should be OK because it is there to protect the cable and therefore a lower rating is acceptable but a higher one isn't. I think what prompted that decision was that my CU won't accommodate an MCB without altering the cover with a Dremel.

He came and did the work last week.

We noticed straight away that the shower didn't need to be turned up so high to get a good temperature. So we benefitted from a bit more power.

However, tonight 2 people used the shower for about 20-25 minutes and we've got the putrid fishy smell back again. The CU cover is noticably hot to touch.

My belief is that the fuse and holder cannot handle the current.
I also think the smell is coming from the pull cord unit which wasn't upgraded. I'm led to believe that these come in different ratings too so maybe we need to upgrade that.

I'm obviously disappointed. And I find myself in the awkward situation of having to tell my friend that his work isn't good enough. The task was to find the cause of the smell and get rid of it.

 

[flameport]

My belief is that the fuse and holder cannot handle the current.

That is correct. The fuseway is 30A. The shower will use over 35A.

If you want to continue using the shower, the only solution is to have a new consumer unit fitted.

Continuing to use the shower will just do more damage to the consumer unit and the cables within it.

 

[ColJack]

ok, be kind, rewind...

did you upgrade the shower?

if not then why on earth are you thinking you don't have to turn it up as high as before by just urgrading the suppli cable?

if not then that's likely the cause of the smell.. the shower itself, something in it overheating..

it could also just as easily be the drains or something else..

 

[roundthebend]

Hey, I'm only speaking as I find. I appreciate what you're implying though and I can only say that maybe it's the warmer weather that means we aren't needing to turn the shower up so high.

Or, the shower has a problem. We didn't replace it.

But, the fusebox cover is getting very warm after showering. I would guess that isn't desirable.

I think what we'll end up doing is having a new CU and a new shower fitted. Deal with the cause, rather than the symptoms maybe? Oh yeah, and the pull cord switch.

 

[ban-all-sheds]

Sounds like a plan.

my electrician friend

Don't use him though.

 

[roundthebend]

Ban - I must admit I'm not full of confidence in his work. However, the wife and I discussed this last night and we said there are only 2 possibilities here:

1. He knows exactly what he's supposed to be doing, but isn't telling us the correct information. Maybe it's because he want to see us burn in a raging inferno, or maybe because he's scared that his original quote is wrong and he doesn't want to give us the bad news. However, I've asked several times about replacing the CU and he's said it isn't necessary.

2. He doesn't know what he's doing. However, he only did his exams just over a year ago so I'd expect his knowledge to be reasonably up to date. Especially on something like this which I suspect is quite a straight forward and common type of job.

If he doesn't know what he's doing, how can we have confidence in anyone else? Maybe it's time to ask around for a recommendation.