Cabling choices for low voltage exterior lighting

[rothbart]

Hi,

I'd like to have five 12V 20W spike spots outside my house, switched altogether, in one string from a single transformerw which must be located at one end. The furthest spot would be 12metres away. The cabling will be shallow buried in flower beds. I understand there are volt drop and current issues and would like to know what power of transformer, what cable type/size and what wiring circuit ' loop???' I should be thinking about. Thanks,

 

[ban-all-sheds]

Transformer is easy - 100W.

Cable size - assuming that the lights are equally spaced along the cable, if my calculations are right, the combined resistance of each length needs to be no more than 40 milliohms.

12m ÷ 5 = 2.4m

So the cable must be no more than 40 ÷ 2.4 = 16.66 mohm/m

2.5mm² flex will do.

 

[breezer]

why not buy a kit? it will all be done for you

you may also want to read this

 

[ban-all-sheds]

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