Hi there i have an outbuilding being built which has 4 double sockets and 2 tube lights i also want to have a running machine and tv in there and occasionally will be using my lawnmower and power drill. So what mm cable should i use as there are so many, some people say 1.5 others say 6 or even10mm i am lost please can you help me.
what type of armoured cable
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Current carrying capacity 1.5mm around 16A and 2.5mm around 20A and 4mm around 25A and 6mm around 32A and 10mm around 45A.
However how it is run and the temperature range of cable will alter these figures. Plus you also need to consider earth loop impedance and volt drop.
So step one is work out load required. And this will jump to the next available MCB size so for a load of 12A a 16A MCB and for 18A a 20A MCB. The MCB size is what you then use to work out cable size.
Next is length of cable. There is a chart giving volt drop per amp per meter and you for lights are allowed a max of 3%.
Then there is the impedance (that's resistance when using AC) that will allow the MCB or RCD or RBCO to trip for example with a B16 no more than 2.875 ohms.
You just don't give the information required to work out what is needed.
Then if on domestic premises since outside Part P will require you to pay the LABC over £100 so they can inspect your work. Is it really worth it. Likely cost more to DIY than get an electrician to do the work.
However how it is run and the temperature range of cable will alter these figures. Plus you also need to consider earth loop impedance and volt drop.
So step one is work out load required. And this will jump to the next available MCB size so for a load of 12A a 16A MCB and for 18A a 20A MCB. The MCB size is what you then use to work out cable size.
Next is length of cable. There is a chart giving volt drop per amp per meter and you for lights are allowed a max of 3%.
Then there is the impedance (that's resistance when using AC) that will allow the MCB or RCD or RBCO to trip for example with a B16 no more than 2.875 ohms.
You just don't give the information required to work out what is needed.
Then if on domestic premises since outside Part P will require you to pay the LABC over £100 so they can inspect your work. Is it really worth it. Likely cost more to DIY than get an electrician to do the work.
And you must be able to test your work and certify it. You will need a set of calibrated test equipment and the knowledge of how to test and use it. You'll have to interpret the results and determine if they comply with BS7671.
Read this before you go further http://www.diynot.com/wiki/electrics:part_p:diy_electrical_work_and_the_law
and then you'll be better getting an electrician to do this for you. Find a local registered electrician at www.competentperson.co.uk
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