Replacing 8.5kw with 9.5kW shower

damoz

Need advice. replacing a shower - want to use a 9.5kw in place of the current 8.5kw one (which has packed up).

The RCD is 30mA. The MCB is 63A i believe. Is this sufficient for 9.5kw shower?

Also, i believe i need 10mm cabling - how do i actually know what it is (measure!?). Have pics if that would help.

tomdempsey200

best advice

get a competent electricuan

2011

I'm with tomdempsey200 on this one.A number of things to consider:The MCB is not suitable for a 9.5kW load. I assume it is "type B" ?This should be selected on the basis of the design current.The protective device should also provide discrimination with the main switch fuse in the distribution board, a 63A MCB is not likley to do this (in a domestic installation). Are you sure that it is an MCB?More information would be required to size the cable correctly. A 10 sq. mm T+E may well be suitable but this can not be verified without knowing lenght of run, ambient conditions etc.. the final circuit arrangement must pass earth fault loop impedance test, not exceed maximum permissable volt drop etc..

damoz

Some images to help - i assume the 63A is the MCB. The manual says minimum 80A - make sense?


Looks like ill need an electrician and a plumber to install this maybe better off sticking with a 8.5kw.

tomdempsey200

most of the board here are rated 63amp

that 80/100 is a UK spec but is better suited to the shower loads

2011

To me the first picture shows a 40A B type RCBO with 30mA current imbalance trip.
The last photo shows a switch fuse which most likely contains a 63A fuse.

tomdempsey200

yes 40amp rcbo...

63amp(main ocpd) board

i meant that the basic UK domestic supply is better suited to showers than the 63amp/12kva we use here

zega

That 9.5kw shower will pull about 41amps.You have a 40amp breaker.

damoz

zega wrote: »

That 9.5kw shower will pull about 41amps.You have a 40amp breaker.

... so needs to be changed? To what? Sorry, it may need to spelt out for me

tomdempsey200

damoz wrote: »

... so needs to be changed? To what? Sorry, it may need to spelt out for me

you can't just swop it out

it's providing overcurrent protection for the cable

that's why you need a competent electrician on the job

or you'll be going round here in circles
with questions and answers

damoz

I intend to get an electrician - just wondering whats entailed, and what it will cost. As i stated, i still have the option to revert to 8.5kW shower.

zega

damoz wrote: »

I intend to get an electrician - just wondering whats entailed, and what it will cost. As i stated, i still have the option to revert to 8.5kW shower.

Get an 8.5kw shower,what that lad above me is saying is that the cables in the walls might not be big enough to power a 9.5kw shower safely.

There's a reason certain size breakers are used,its to protect the cable from carrying more current than its designed for,So thats why you cant just stick on a 50amp breaker(for example),hence why you'll need an electrician

solargain

+ 1

dodzy

tomdempsey200 wrote: »

best advice

get a competent electricuan

tomdempsey200 wrote: »

that's why you need a competent electrician on the job

or you'll be going round here in circles
with questions and answers

Super assistance given there. Would you not just answer the OPs questions ? I think they know they need a sparks, but it still wouldn't hurt to be a little more helpful.

2011

dodzy wrote: »

Super assistance given there. Would you not just answer the OPs questions ? I think they know they need a sparks, but it still wouldn't hurt to be a little more helpful.

Cool your jets.

The OPs questions have been answered so far as is possible.
Some sound advice has been given.

tomdempsey200 is trying to avoid a situation where the OP takes on something that is beyond his/her capabilities.
The fact that 230V is potentially lethal is often forgotten by DIY people.

dodzy

2011 wrote: »

Cool your jets.

The OPs questions have been answered so far as is possible.
Some sound advice has been given.

tomdempsey200 is trying to avoid a situation where the OP takes on something that is beyond his/her capabilities.
The fact that 230V is potentially lethal is often forgotten by DIY people.

Apologies if my post was offensive. It's just annoying when someone chimes in here with the same ole "get a qualified whatever". Case and point, the first response to the OPs question, #2. Now, comparing this to your first response, #3, basically says the same thing, but you provided some info also. Big difference.

This place is a great source for advice on bloody everything, but just once, I'd like to see similar posts answered with something other than that same predictable line. By all means refer to a qualified professional, but at least go some way towards answering the questions.

2011

dodzy wrote: »

By all means refer to a qualified professional, but at least go some way towards answering the questions.

I think that this has been achieved here.

The aim of this forum is not to turn laypersons into the equivalent of qualified electricians. Although it can assist some to deal with the fundamentals and help people to speak the "electrical language" it is important to inform people when something is beyond them.

You honestly would not believe some of the things that I have seen people attempt over the years. A little knowlage can kill!

Unfortunately most electrical items in the home will "work" once they have a phase and neutral connected to them (even when the polarity is reversed). This can mislead people into thinking that the devices are correctly wired and will work safely.

hufpc8w3adnk65

dodzy wrote: »

Apologies if my post was offensive. It's just annoying when someone chimes in here with the same ole "get a qualified whatever". Case and point, the first response to the OPs question, #2. Now, comparing this to your first response, #3, basically says the same thing, but you provided some info also. Big difference.

This place is a great source for advice on bloody everything, but just once, I'd like to see similar posts answered with something other than that same predictable line. By all means refer to a qualified professional, but at least go some way towards answering the questions.

Yes this place is great for advice on gardening, cycling, football streams etc etc etc! There's a reason we spend 4 years serving our time and why it's now illegal for non registered electricians too do a lot of works! The poster has shown in his first post hes not competent enough too carry out this job and by us telling him here how too do it could result in serious injury or worse!

dodzy

MrMac84 wrote: »

Yes this place is great for advice on gardening, cycling, football streams etc etc etc! There's a reason we spend 4 years serving our time and why it's now illegal for non registered electricians too do a lot of works! The poster has shown in his first post hes not competent enough too carry out this job and by us telling him here how too do it could result in serious injury or worse!

I think that the OP gets your point regarding his/her incompetence at this stage. As you can see below, they had indicated that they were "intending on getting an electrician". I think that your post above highlights what was contained in my earlier post, perfectly. Thankfully, 2011 has answered the OPs questions combined with the recommendation of seeking RECI help (that's all that was requested), as it's obvious your intention was to do nothing of the sort.

damoz wrote: »

I intend to get an electrician - just wondering whats entailed, and what it will cost. As i stated, i still have the option to revert to 8.5kW shower.

And FWIW, I've seen work carried out by more than one "qualified" electrician. "Shoddy" would be an understatement, so don't tell me that just because someone is registered, quality & safe work is a guarantee.

markad1

MrMac84 wrote: »

Yes this place is great for advice on gardening, cycling, football streams etc etc etc! There's a reason we spend 4 years serving our time and why it's now illegal for non registered electricians too do a lot of works! The poster has shown in his first post hes not competent enough too carry out this job and by us telling him here how too do it could result in serious injury or worse!

It was 5 years when i served my time .....your either
a: young and it's changed since i done it or
b: your old and your memory is gone

only teasing you MrMac

2011

dodzy wrote: »

And FWIW, I've seen work carried out by more than one "qualified" electrician. "Shoddy" would be an understatement, so don't tell me that just because someone is registered, quality & safe work is a guarantee.

Unfortunately it is a fact that some electricians (including those that are registered) have produced some horrendous work over the years particulary during boom times. However the solution is not to let just anybody "have a go".

This is something that CER has being trying to address. Tough new legislation was brought in last year to deal with offenders, I have read about prosecutions already. Even when an inspector from (for example) RECI deems work to be of sufficient standard there is now the option to take the complaint to another level by reporting it to CER. I have been very disappointed with RECI inspections in the past. Hopefully in time the poor standards of workmanship that we have seen from some electricians will be a distant memory.

tomdempsey200

what is the current-carrying capacity of 6sq T+E in domestic installs?

shower on ground floor

shower on first floor

hufpc8w3adnk65

markad1 wrote: »

It was 5 years when i served my time .....your either
a: young and it's changed since i done it or
b: your old and your memory is gone

only teasing you MrMac

I done phase 2 15 years ago

Bruthal

tomdempsey200 wrote: »

what is the current-carrying capacity of 6sq T+E in domestic installs?

shower on ground floor

shower on first floor

The actual current capacity of a cable would be the same no matter how long the cable is. Its all about the volt drop.

tomdempsey200

Bruthal wrote: »

The actual current capacity of a cable would be the same no matter how long the cable is. Its all about the volt drop.

yes... I mean 'install methods' not length of run obviously

what are the capacities ballpark for different domestic installs

bungalow,ground floor,first floor locations

damoz

kinda sorry i asked now. I just wanted some advice, as the professional i had to put in the shower was not clued in (him been a plumber and all). So. now i will have to get both an electrician and a plumber. Think ill just go back and get the 8.5kw and save the time, money and hassle. Cant for the life of me get an electrician who has time of day for a small job like this...

Sleeper12

You do need a good electrictian on this one. I'm guessing you are going to pay around €200 to get him / Her to replace 6mm with 10mm cable, swap the showers (price of shower not included) & change pull cord switch. The rcbo I think you are stuck with. I think you need a 45amp rcbo but they only come in 40amp. As far as I know this means it might trip every now & then. I'd be more worried about cable size. 6mm suits up to 9kw on a max of 15 meter run (I think). If you had a 16 meter or longer run you would need 10mm even for 8.5kw

2011

tpmcompany1 wrote: »

I think you need a 45amp rcbo but they only come in 40amp. As far as I know this means it might trip every now & then.

Believe it or not I had a 32A RCBO on a 9.5kW shower in my home for years and it never tripped. If you look at the fusing characteristics you will see why.

tomdempsey200

2011 wrote: »

Believe it or not I had a 32A RCBO on a 9.5kW shower in my home for years and it never tripped. If you look at the fusing characteristics you will see why.

yes

but it's a breach of wiring rules all the same

frankmul

zega wrote: »

That 9.5kw shower will pull about 41amps.You have a 40amp breaker.

2011 pointed out in a thread before that a shower rated at 9.5 kW /240v is only a 9.1 kW shower here at 230 volts. In one of the shower manuals. Current works out just below 40 amps. 40 amp rcbo should be ok then.
The cable would be the weak point. Needs to be sized correctly.

tomdempsey200

frankmul wrote: »

2011 pointed out in a thread before that a shower rated at 9.5 kW /240v is only a 9.1 kW shower here at 230 volts. In one of the shower manuals. Current works out just below 40 amps. 40 amp rcbo should be ok then.
The cable would be the weak point. Needs to be sized correctly.

they're usually marked on the box time

230 and 240 ratings

maybe it's a 230/9.5