size of cabbel

[seddrick555]

hi all i want to put power into my garage to run a tumbel dryer and a small chest freezer with a coupel of lights in it and was wondering wat size of cabel i would need to this would be gratefull for any info

 

[ericmark]

Not as easy as that. I would guess at 20A supply but also need to know distance of run and would be better if knew loop impedance at origin too.

 

[Taylortwocities]

Design Procedure
Determine the design current Ib
Select the rating of the protection In
Select relevant correction factors (CF)
Divide In by the relevant correction factors to give It
Choose a cable size to suit It
Check for voltage drop


Simples!

Meerkat

• Taylortwocities
• 11 Dec 2009
• 53

 

[streetlighter]

can you give us the length of run!??!?!?

 

[JohnW2]

.....and would be better if knew loop impedance at origin too.

Design Procedure
Determine the design current Ib
Select the rating of the protection In
Select relevant correction factors... etc....

My goodness - am I too conclude that whatever BAS has is catching?

If folk want, very reasonably, to tell an op that things are more complicated than (s)he probably realises, and that it would therefore be best to employ a professional, wouldn't it be far more sensible to just say so, rather than playing with this 'blinding with science' stuff??

Kind Regards, John/

 

[ovoloknight]

I would say the easiest way to do this (assuming you live in a regular sized house) without doing any long calculations and having to worry if the cable will be big enough etc is to wire a ring main circuit from your consumer unit to the garage i.e.
A 2.5mm twin and earth cable from your consumer unit, into the garage and then to your first socket (tumble dryer)
From that socket to the next socket (fridge freezer)
Then from that socket to a switched fused spur (for lights)
And finally back from to the board.

For the lights take a 1.5mm twin and earth cable from the outgoing side of your switched fused spur to your light. (for more lights just loop from the first to the second light and so on)

Hope that helps.

 

[securespark]

Ovo

Are you implying a 20A RF circuit?

 

[EngStudent]

I would say the easiest way to do this (assuming you live in a regular sized house) without doing any long calculations and having to worry if the cable will be big enough etc is to wire a ring main circuit from your consumer unit to the garage i.e.
A 2.5mm twin and earth cable from your consumer unit, into the garage and then to your first socket (tumble dryer)
From that socket to the next socket (fridge freezer)
Then from that socket to a switched fused spur (for lights)
And finally back from to the board.

For the lights take a 1.5mm twin and earth cable from the outgoing side of your switched fused spur to your light. (for more lights just loop from the first to the second light and so on)

Hope that helps.

Who does that help?

What happens if the garage isn't attached? Should he still run a ring final to his garage? What's wrong with a suitably sized radial? What's the Ze of his supply? How do we know it'll meet disconnection times?

OP; How far from your consumer unit is your garage? Is it attached to your house? Besides your dryer, freezer & lights, do you plan on having anything else in there? Tools, for instance?

As said, you're best off employing the services of an electrician.

 

[bernardgreen]

I would say the easiest way to do this (assuming you live in a regular sized house) without doing any long calculations

Easy but not necessarily safe !

 

[Taylortwocities]

My goodness - am I too conclude that whatever BAS has is catching?
/

What, do you mean planning and doing a job properly?

 

[1john]

Someone replies and explains how to do the job properly, someone complains about that person saying how to do the job properly and then someone comes along and tells the OP to run a "ring main" to his garage, which could be 30 feet or more up the drive!?!

OP, we need alot more information, or if you didnt realise that you need an electrician.

There is nothing wrong with explaining how to do a job properly, infact it should make for a safer DIY job as anyone with any intellegence will go and look up Ib In ect and start to have a better understanding of what they are doing, and why they are selecting certain materials for that job. They will also come to realise how important testing is, and why it is essential before energising any new circuit. Just assembling some parts and blindly switching on whilst hoping for the best, treating electrical install work like an airfix model is just stupid and crazy! People die due to neglegence with electrics and with the cirrent freedom allowed for people to tinker and bodge things up I think the more people who decide to do their own wiring get properly educated and understand what they are doing the better.

 

[JohnW2]

My goodness - am I too conclude that whatever BAS has is catching?

What, do you mean planning and doing a job properly?

No, as far as I am concerned, telling people how to plan and do a job properly is fine, even though some here might suggest that one shouldn't do that if one feels the op is not competent to do it.

What I was talking about is explaining 'how to plan and do a job properly' but, in doing so, deliberately using technical terminology or jargon which one believes (and probably hopes) will almost certainly not be understood by the op - with, I presume, the motive of making the op realise that the subject is 'over their head'.

As I said, if one wants to tell an adult that one would advise them not to attempt to do something, one should simply say so. If they then persist in saying that they will do it, anyway, then one has to make a personal decision about the dilemma I recently discussed with BAS as to whether it's better to try to help them do it more safely, or whether one should refuse to do that on the basis that it 'encourages' them.

Kind Regards, John.

 

[JohnW2]

... someone complains about that person saying how to do the job properly ...

I presume that is a reference to me. As I've just explained to TTC, I was not 'complaining' (if that's the right word) about saying to how to do a job properly (which I fully support) but, rather, about explaining how to do the job properly, but deliberately using language which one expects/hopes the op will not understand (with, I assume, the motive of making an entirely different pont).

Kind Regards, John.

 

[ericmark]

It worries me when without details people try to explain how to do a job which the poster is likely to follow without realising he is doing anything wrong.

To refer to Part P (Although in this case in Scotland so nothing to do with Part P) is good. But to say because of Part P you can't do the job just means the poster goes else where and any advice on real safety is lost.

I have seen some real complex wiring done for a shed of garage but normally all one needs is a fused connection unit. In this case because of load then some simple consumer unit is likely required.

From the description I would guess between a 20A and 32A supply is required which will likely mean between 2.5mm to 10mm cable according to current and distance.

To my mind to give such a wide range is unlikely to help the guy much. Likely 6mm SWA cable will be ample and since it can still fit in a 20mm gland will likely be what would be selected by an electrician.

However the poster may own his own a wood and the garage could be 1/2 a mile down the road. In which case you may need 25mm SWA. It could also be 3 feet from the house and one could run a 4mm radial or 2.5mm ring from the house consumer unit and use a FCU for lights with 3A fuse fitted.

I am sure the poster can easy come back with more information and allow use to give him some useful replies.

I would agree that really we should measure the ELI and testing and inspecting is very important. But I think to expect a DIY guy to hire the test set at £75 a week is unrealistic.

Where the post says "Can I" or "Am I allowed to" then to say how it needs to be tested and inspected is really what the guy has asked about. But that was not the question here.

I hope I am not another BAS but neither do I want to make DIY guys think they are doing a proper job when clearly they are not.

I am sure the guy will come back with more information and once he has I am sure we can direct him how to do the work at a reasonable cost.

The RCD question I forgot to raise. Likely it will require a RCD which could be fitted in many ways. It may be already fitted to house consumer unit. It could be fitted in the garage. Either in a consumer unit or as part of the sockets.

The tumble drier is the problem, without that likely a FCU would do the job. There are models now designed to run over night with just a 5A load and by selecting a low current type which of course take longer to dry cloths he may be able to get away with a FCU supply.

If he can limit the power to 13A then the price drops. A RCD FCU in the house would mean a cheap job. Also lighter cable and a switched FCU for lights would mean no need for a consumer unit.

The freezer in a detached out building worries me. RCD's do trip and one needs to know it has tripped. I fitted an 8 watt outside lamp to my shed when it had a freezer so at a glance I could see if anything had tripped. Well at least at night I could as on a cell. And 8W will not break the bank.

But found my wife would fill it OK but then it just sat there and food went out of date before it was used. So the idea of a cheap to run chest freezer did not work so now use a frost free upright in kitchen. With display so again a glance shows if no power.

 

[ban-all-sheds]

I would agree that really we should measure the ELI and testing and inspecting is very important. But I think to expect a DIY guy to hire the test set at £75 a week is unrealistic.

Then DIYing is unrealistic.

Simples.

End of.

Over and out.

etc.

The freezer in a detached out building worries me. RCD's do trip and one needs to know it has tripped.

There's also the issue of whether the freezer will work properly in the lowest ambient temperatures it will experience in the garage.

seddrick555 - what's the coldest it gets in the garage?