Size of shower cable

[Bensen]

Hey what kilowatt showers can be feed off 6mm cable and which need 10mm? I guess the distance from the fuse board also needs taking in to account?

 

[telectrix]

We are putting in new shower supplies in at Clapham.

5.8kW = 37A
40A OCPD required
single cable in surface trunking has a max of 41A for 6mm cable.

6mm cable it is then...

well at least get ohm's law right. 5800/230 = 25.22 A according to my arithmetic.

 

[shanky887614]

well at least get ohm's law right. 5800/230 = 25.22 A according to my arithmetic.

ah but it wouldnt be a 5.8 would it.

i have only come across 6,8.5 or 10kw electric shows

the manufacturer's like round nunbers

 

[Guest125]

ah but it wouldnt be a 5.8 would it.

i have only come across 6,8.5 or 10kw electric shows

the manufacturer's like round nunbers

Talking od typos........LOL

 

[baldsparkies]

well at least get ohm's law right. 5800/230 = 25.22 A according to my arithmetic.

Yer right Tel.
But why 230v ?? is this by enquiry, assumption, or a true measured rms voltage.
Thinking outside the box (not recommended for DIY man, go away)
but food for thought never the less.
Be gentle with me no more abuse pleeeeese, lol.

 

[shanky887614]

Yer right Tel.
But why 230v ?? is this by enquiry, assumption, or a true measured rms voltage.
Thinking outside the box (not recommended for DIY man, go away)
but food for thought never the less.
Be gentle with me no more abuse pleeeeese, lol.

if its 250 then it would be less.

its rare to see 220v and even then it would only increase a little

 

[Andy78]

Yer right Tel.
But why 230v ?? is this by enquiry, assumption, or a true measured rms voltage.
Thinking outside the box (not recommended for DIY man, go away)
but food for thought never the less.
Be gentle with me no more abuse pleeeeese, lol.

It is standard practice to use the nominal Uo value for all calculations.

 

[Silly Sausage]

if its 250 then it would be less.

its rare to see 220v and even then it would only increase a little

No no no!
The current will increase with voltage.
The power rating is quoted at a certain voltage.

 

[telectrix]

beat me to it. using 230V will give a worse ( higher) value for current than using the actual ( 235 -240V ) so errs on the side of caution.

 

[baldsparkies]

Its even more rare to see 230v shanks, and often that's the baseline that's used for obvious reasons.
And yet when I dared to suggest 6mm as a possible cable size for 8.5kw I was summary abused ??
Despite that, it will be used. And if Mr DIY is going to use it it's wrong.
But on an electricians forum, and with all other factors taken into account,can and does prove satisfactory in the real world.
So there you have it, some people are getting trashed for saying 6mm, some people quite happy to use 6mm.
Hope others are paying attention here, cus amongst qualified electricians there are indeed differences of opinion, and you know what dependant on the situation both are entirely correct.
And that's the whole point, and no abuse needed.

 

[GEOFF S]

Well if Baldsparkies wasn't bald, he will be now! Crikey, a vague question got a vague answer, like most questions and answers on the forums! All this bickering over such trivia lol. Come on chaps

 

[baldsparkies]

Well if Baldsparkies wasn't bald, he will be now! Crikey, a vague question got a vague answer, like most questions and answers on the forums! All this bickering over such trivia lol. Come on chaps

I started off bald so I have nothing to lose.
But nine pages in, what the hell do you think the DIY electrics, plumber feels like who asked the damn question in the first place. lol.

 

[D Skelton]

Its even more rare to see 230v shanks, and often that's the baseline that's used for obvious reasons.
And yet when I dared to suggest 6mm as a possible cable size for 8.5kw I was summary abused ??
Despite that, it will be used. And if Mr DIY is going to use it it's wrong.
But on an electricians forum, and with all other factors taken into account, can can and does prove satisfactory in the real world.
So there you have it, some people are getting trashed for saying 6mm, some people quite happy to use 6mm.
Hope others are paying attention here, cus amongst qualified electricians there are indeed differences of opinion, and you know what dependant on the situation both are entirely correct.
And that's the whole point, and no abuse needed.

I swear to God you're gonna start seeing some abuse in a minute if you don't settle down!!

NOBODY HERE HAS ABUSED YOU YOU PITY SEEKING LOP!

It wasn't your suggestion about using 6mm cable on an 8.5kW shower that was wrong, this was just inaccurate. What was wrong however was for you to 'suggest' in the first place! What is so bleeding hard for you to understand?! You've been told God knows how many times already!

No matter how much detail you go in to about cable calcs, design, derating blah blah blah, when you are describing how to do something to a plumber on an ELECTRICIAN'S forum, all they will see is "put an 8.5kW shower on a 6mm cable".

Please tell me that this has sunk in finally?!

 

[Andy78]

I started off bald so I have nothing to lose.
But nine pages in, what the hell do you think the DIY electrics, plumber feels like who asked the damn question in the first place. lol.

Equally clueless as to when he asked the question hopefully.

 

[baldsparkies]

Paperworks all done,time to go off and earn some pennies.
Hope you all have a good day guys.

 

[Anthony S]

i think you have a typo mate.

you put 5.8kw i think you mean 8.5

Genuine mistake and he gets abused ie accused of being a dxck lol

I have to laugh because you couldn't make it up :6:

 

[Guest125]

Genuine mistake and he gets abused ie accused of being a dxck lol

I have to laugh because you couldn't make it up :6:

Shocking that it is allowed to happen. I just got banned for starting a harmless thread in which I even said I was only joking. It will be interesting to see what is dished out after reading some of these replies.

 

[Anthony S]

Shocking that it is allowed to happen. I just got banned for starting a harmless thread in which I even said I was only joking. It will be interesting to see what is dished out after reading some of these replies.

I have to laugh because I spotted the error straight away and I'm sure a few others did.

Ideal opportunity to dig you out though, if your that way inclined, nice little cover.

 

[Knobhead]

beat me to it. using 230V will give a worse ( higher) value for current than using the actual ( 235 -240V ) so errs on the side of caution.

Wrong.

 

[telectrix]

not wrong, IMO. yes, i know that the lower the voltage means a lower kWage. what i meant was if you calculate from the quoted kW @ 230v you will get a higher value for A than if you'd used 240V. as in I=P/V

 

[Knobhead]

7kW @230=7.55Ω=30.43A

220V=29.11A
240V=31.75A
250V=33.08A

The resistance is regarded as constant.

 

[HandySparks]

Wrong.

Maybe showers should be rated in ohms. That'd confuse the DIYer; the lower the number, the hotter the water.

 

[telectrix]

7kW @230=7.55Ω=30.43A

220V=29.11A 6.4kW
240V=31.75A 7.62kW
250V=33.08A 8.2

The resistance is regarded as constant.

so, power output varies with the voltage.

 

[Geordie Spark]

Wrong.

Morning Tony ... You're up early.

 

[Knobhead]

so, power output varies with the voltage.

Which make using U[SUB]o[/SUB] a load of bolloxs.

 

[Guest77]

Ohms law= current in proportion to potential difference (voltage) if temperature is constant.

 

[Guest77]

Morning Tony ... You're up early.

Hi-Geordie, hows you doing bud?

 

[Knobhead]

Ohms law= current in proportion to potential difference (voltage) if temperature is constant.

And therein lies the problem.

 

[Geordie Spark]

Hi-Geordie, hows you doing bud?

Not bad thanks Mark.

Bored out of my skull though .... wanting to be DOING things instead of sitting about all day.

 

[Knobhead]

Why, finally it's going somewhere.

 

[Geordie Spark]

Why, finally it's going somewhere.

Amazing!!

My flabber has never been so ghasted!!

You've only been here five minutes and you've got them all sorted and quaking in their boots!! :53::laugh: