current regs/ best practice/ exterior wall lightning and sup

[stevethebiker]

hi guys and gals..

can someone advise me on two projects

no. 1

running cable out to some exterior lighting.

this is going on the wall of the property 8ft off the ground.

fed from a switched fused (3a) spur from the socket ring, (32a trip and rcd in mcb)

what is advised for the outside section normal 1.5 t&e with trunking, and what sort.. or armoured

no. 2

power supply to an outhouse/ workshop approx 20mtrs from the mcb for light and sockets ( office equip/ light use)

i am thinking 16a breaker on the rcd sie of the mcb. 2.5mm armoured cable, clipped to a wall all the way there, small unit with rcd protected 16a and 6a trips for sockets/lighting

there will be inspection and testing when the mcb is upgraded later on in the build but i want to get this in place in advance



anything i should know. ??

 

[ban-all-sheds]

what is advised for the outside section normal 1.5 t&e with trunking, and what sort.. or armoured

If you really must run the cable along the outside of the wall, trunking will look naff.

SWA would be good, or TRS or Hituf flex. What sort of provision is there in the light for fitting glands?

i am thinking 16a breaker on the rcd sie of the mcb. 2.5mm armoured cable, clipped to a wall all the way there, small unit with rcd protected 16a and 6a trips for sockets/lighting

OOI, how did you come up with that size?

there will be inspection and testing when the mcb is upgraded later on in the build

Which MCB?

but i want to get this in place in advance

anything i should know. ??

If the I&T is associated with getting Building Regs approval in E&W then you should know that it doesn't work like that - you can't present a fait accompli to an electrician and expect him to say he did it.

 

[Taylortwocities]

There is no point putting the feed/MCB for the outhouse on the RCD side of the board and then having another RCD in the outhouse.

Assuming the cabling to the outhouse is not buried in the walls of the house:
put an MCB of the correct value (that will be determined by the SWA cable size) in a non-RCD protected way on the consumer's unit

All that you plan is notifiable work.

 

[wingcoax]

Reading the op it looks as though he means CU when he says mcb.

 

[stevethebiker]

ok guys, thanks for the sound advice.. i am trying to help out an old friend who has bought what looked like a great home to retire in, but now finds it is a dogs dinner..

was trying to save on sparky fees, but i have to admit i was in two minds about it..

out of interest when she gets the work done, what size cable should be specified for the run to the outhouse. it will not be buried at any stage. the 2.5mm was just an assumption based on what i know from internal circuits..

the last guy she got in, (reg sparky) overcharged her badly and still managed to do illegal work.. (radials off a ring circuit with no fused spur)

 

[ban-all-sheds]

out of interest when she gets the work done, what size cable should be specified for the run to the outhouse. it will not be buried at any stage. the 2.5mm was just an assumption based on what i know from internal circuits..

• //www.diynot.com/forums/viewtopic.php?p=81696#81696
• http://www.tlc-direct.co.uk/Book/4.3.1.htm
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/cableselection_web.pdf
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html