Replacing a shower yourself

hubb

zax47 wrote: »

Nope - that's the neutral! Pretty sure it would be. The give away that a DIYer fitted that is that a sparky wouldn't wrap the incoming earth in yellow/green tape - we'd have the correct sheathing.

With all due respect, if you couldn't correctly identify that melted mess as the neutral connection then please do get a professional in. Given the melting sheath on the incoming live as well, I would suggest that the supply cable is probably undersized for the shower - looks like only a 4mm cable to my practiced eye, only good enough really for a 7kW shower.

That damage can be repaired, but needs a sparky. I have big concerns about that supply cable size though.

Oh dear, I have already purchased the new 9.5 kw from Screwfix but I think the cables may be ok as 2 cables going to the switch are 15mm wide so seems thick enough. Yes, I meant to say neutral, not earth. I do know the difference as I have been changing plugs since a boy. I will add that we inherited this shower and wiring from the previous owners.

zax47

You know cables are sized by conductor cross-sectional area, in sq. mm? So a "4mm" cable would have live & neutral cores with conductors each of 4 sq. mm CSA.(earth is generally smaller, so 2.5 sq.mm in this example)

The clue as regards yours probably being only 4 sq. mm is that the earth wire is a single core - for 6mm or 10mm twin&earth I would expect it to be stranded/multicore. I wouldn't be happy to hang anything bigger than 7kW on what you've got there. What size fuse/breaker is protecting the shower circuit?

hubb

zax47 wrote: »

You know cables are sized by conductor cross-sectional area, in sq. mm? So a "4mm" cable would have live & neutral cores with conductors each of 4 sq. mm CSA.(earth is generally smaller, so 2.5 sq.mm in this example)

The clue as regards yours probably being only 4 sq. mm is that the earth wire is a single core - for 6mm or 10mm twin&earth I would expect it to be stranded/multicore. I wouldn't be happy to hang anything bigger than 7kW on what you've got there. What size fuse/breaker is protecting the shower circuit?

Well I will have to get this new one installed somehow. Here is the (black) switch for the shower currently installed:

zax47

Sorry, had to go earn a living...

40A is borderline for a 9.5kW shower, but it's to protect the cable not the device (even more to suggest it's only a 4mm cable, I'd suggest). I rarely do a new install that isn't 50A MCB or RCBO, & 10mm cable as most people want a 9/9.5/10kW shower. Retro-fit can be a real pain, seeing as we're duty-bound to fit RCD protection somehow, if it's not already in place.

Get a sparky in and go by his advice.

hubb

zax47 wrote: »

Sorry, had to go earn a living...

40A is borderline for a 9.5kW shower, but it's to protect the cable not the device (even more to suggest it's only a 4mm cable, I'd suggest). I rarely do a new install that isn't 50A MCB or RCBO, & 10mm cable as most people want a 9/9.5/10kW shower. Retro-fit can be a real pain, seeing as we're duty-bound to fit RCD protection somehow, if it's not already in place.

Get a sparky in and go by his advice.

I wish. I have invited a few via Rated people, my builder stating I am ready to hire but non of the beggers have bothered. Couple of years ago was a different story. When ever I posted a job on those sites I was beating them off with sticks. Gues the recession is over.

zax47

hubb wrote: »

I wish. I have invited a few via Rated people, my builder stating I am ready to hire but non of the beggers have bothered. Couple of years ago was a different story. When ever I posted a job on those sites I was beating them off with sticks. Gues the recession is over.

Didn't I say what the issue is with those sites. Not worth a tradesmans time replying now as we have to pay to even get your contact details! Not only do I have to pay to be a member, it's £5+ each time I want to know more about a posted job, maybe 8 or 10 reply and only 1 gets the job.... So I pay to get details of 8 jobs, get none, £40+ wasted.

Ask friends/enemies/neighbours/relatives etc. Look on the Competent Person site I linked to. Plenty of ways to find a sparky with a little effort. Hell, if you are on FaceBook there will any number of local buy/sell pages where you can ask for recommendations from local people.