armoured cable query

i currently have a 50 metre 6mm armoured cable running to an out building. i am now thinking of converting it into a garden annexe and putting a 9kw elec boiler, elec cooker etc

will the 6mm cable be good enough or will i need to run 10mm or even a 16mm armoured cable.

thx in advance

How much power are you going to use exactly?? The existing cable might be ok for lighting and some sockets but you'll need another cable run in more info required.

6mm is not going to be big enough to supply a 9KW boiler plus the normal load of a residence over that distance.

Guessing at about 15KW total load with the cooker and shower on you probablly need 25mm cable fed from an 80A switchfuse. If you have large electric loads in your house as well then you could be really pushing the limits of your service fuse (though in practice you will probablly get away with it because service fuses are very slow to blow at moderate overloads)

another option would be to leave the electric cable as it is and get gas run for heating and cooking.

It sounds like people will be living down there. The building control may have something to say about this. Best ask them if you plan to create a habitable space!