Diversity factor on rewire

[Percyprod]

I'm going to rewire my house, and was wondering if it's ok to have 2 shower circuits as well as cooker, sockets and lights off 1 cu, or would it be better to have 1 of the showers on a separate cu, because of the available water pressure the 2 showers are never on together.

 

[Pete999]

I'm going to rewire my house, and was wondering if it's ok to have 2 shower circuits as well as cooker, sockets and lights off 1 cu, or would it be better to have 1 of the showers on a separate cu, because of the available water pressure the 2 showers are never on together.

How are you intending to limit the usage of the showers to 1 at a time? if you go the route you have outlined all on the same CU is fine, You will of course need to apply diversity to the whole installation not just the showers and cooker.

 

[Percyprod]

I'll use the same method I do now - " I'm having a shower, don't run any water!". I was just wondering what usual practice was, it's not a big house, and only 3 people. I appreciate diversity is applied to the whole installation.

 

[Strima]

Contractor which allows only one shower to be used at a time. Also what size is the mainDNO fuse?

 

[Percyprod]

Interesting point. Can't be bothered fitting contactor, no need. Was told by engineer that 80 amp is big enough fuse for cut-out, as very few properties need 100 amp. Any way, I fitted 100 amp fuse when I fitted meter. His arguement was that if you fit 100 amp it could get too hot if you are pulling 100 amps. My reasoning is that an 80 amp will get even hotter, as it will take the 100 amps for quite some time. Any way cut out is 100 amp.

 

[Jamie']

Could always add a booster for your main water?

Not sure why you would want 2 electric showers if your only ever going to use one at a time?
Diversity doesn't apply to showers either so if your using 10.5kw showers and both are on at the same time your going to be drawing 90amps so your Your not far away from your 100amps cut out.

 

[Octopus]

Maybe ask BCO and see what they say ...

 

[Percyprod]

Long story, but basically had extension build, and lost part of one bedroom. Decided to make that into another toilet, and as couldn't fit a bath fitted a shower. Like I say, never used together, certainly not going to pay for pump. Why should we ask the Big Chocolate ourangatan?

 

[Octopus]

Why should we ask the Big Chocolate ourangatan?

Well, non scheme member doing rewire in England - surely you're going to notify BCO before you start so they can inspect at every stage?

 

[Strima]

Well, non scheme member doing rewire in England - surely you're going to notify BCO before you start so they can inspect at every stage?

Judging by previos posts I doubt it.

 

[Percyprod]

Nah he'll never know.

 

[mhar]

Well you have been given the correct answer that there is no diversity allowed with showers.
However I did a cu change a while back at busy holiday cottage which had quite happily been running 3 x 8.5kW showers plus all the normal appliances for the last 10-15 years through a 60A fuse. The main shower now fed by a combi
Isn't it only a DNO network planner who can decide on the size fuse you have? What is the rating of your meter? I think you may have misunderstood the 100A fuse issue, the fuse carriers were overheating before the fuse would blow therefore whenever seen (this is what happens locally) they are reduced to 80/60A so that the fuse blows before the carrier gets too hot. What size supply does your supply agreement state? Locally our agreements are for 15kVA so an 80A fuse is the most suitable.

 

[MJPD29]

Seems like quite a lot of work for a DIYer, how do you intend to test and certify it?

 

[Pete999]

Seems like quite a lot of work for a DIYer, how do you intend to test and certify it?

Seems odd every time that question is asked of a DIYer it goes all quiet

 

[MJPD29]

Seems odd every time that question is asked of a DIYer it goes all quiet

I actually got a call from someone on Wednesday asking if I could test and certify 2 semi detached houses that the owner had wired, saying his electrician had let him down and he'd ran out of time, but as he had some knowledge 'of electrics' he's done it himself, including all 2nd fixing. I don't know about anyone elses opinion but I wont be doing it there is no chance i would sign my name under a full rewire by a DIY expert

 

[Percyprod]

Very often DIY jobs are done to a higher standard than those done by so called proffesionals, so let's not go down that road. Any way, I suppose that means none of you would do any work on your car or van, as you're not 'a professional'? Actually what I meant was is it normal practice to fit 2 showers in a cu. I know there is no diversity on their use. As stated they won't be used together. And Mathewd29, if you don't know how to wire and test a shower it's not up to me to tell you!

 

[MJPD29]

I am not having a go at you, and I disagree with your statement about DIY work being better, maybe it is in a very rare case, but more often it is dangerois and potentially deadly. I am not a so called professional, in fact I am a professional.

 

[Percyprod]

My comments wern't aimed at you personally Matthew, I don't doubt you professionalism, nor for electrical work either, but in general a lot of diy do a very good job, whatever it is, and some professionals don't. Perhaps I gave the impression I think most diyers are better, not what I meant. Like I say, many motorists do work on their cars, which is possibly potentially more dangerous than doing some wiring, and they have no mechanical training, but they do as good a job as a garage would. I just don't agree that unless you have the necessary electrical ticket you can't do a safe job that complies with the regs, other than not being signed off.

 

[Resu]

You don't need a ticket, you need to be competent. Your original question proves a lack of competence.

There is a line when dipping into other areas of expertise. I'm sure many people could change the oil and filters in their car without being mechanics but wouldn't try and change a gearbox.

They would likely struggle to do an MOT too without having the right paperwork to back them up!

And Mathewd29, if you don't know how to wire and test a shower it's not up to me to tell you!

Why should it be up to us to tell you how to do it!

 

[Percyprod]

No, but a lot of people would do work on the brakes, suspension etc. I am perfectly competent, it was just a simple question on what other people do. All work I do is perfectly safe. If it is not, then as I have worked to the regs then you are saying they are wrong.