Hi all,
Planning on wiring my neighbour's summer house which will be 15 metres away from the end of the house (20-25 metres total distance from the supply CU under the stairs).
Need some advice on which option would be the most SAFE not just the quickest, cheapest method etc. If it costs more to be done properly then that’s how it will be done.
The electrical needs for the shed are:-
LED lighting
Power for a treadmill 1000w and heater 2000w
The situation is this - the house has been underpinned and has no access under it for running cables. The CU being where it is means it would be a tricky albeit not an impossible SWA run along the outside of the house, that's before you get to the drop down to the garden trench for the final stretch to the shed. The alternative to running it that way is going out to the wall behind the CU first then down under the driveway to the garden, although this would mean raising a fair few flags. I know this may sound lazy but I don't want to be lifting 5 metres of driveway flags to run the cable under that way, but if that is the best way so be it. Ideally I would prefer not to use a full run of 25 metres of SWA but again, if needs must.
There is a ring main socket situated on the downstairs back room wall adjacent to the rear garden that has a T+E 2.5mm2 coming out to a junction box on the exterior wall directly opposite. This JB is supplying flood lights (which don't work!).
Here's my first thought...
Could I replace the JB on the ext wall for a 13A FCU spur inside a waterproof casing (Doing away with the existing flood light cables) Run a 2.5mm SWA from this, bury it a foot deep along the side of the garden to one metal-clad double socket inside the shed avoiding the need for a sub-CU. Then feed off from this to an additional FCU switch 3A for the lighting circuit?
Here’s where I need guidance?
Will spurring off the downstairs 32a MCB ring main be ok for the distance and load etc?
If so, will SWA 2.5mm be enough or upgrade to 4mm, or 6mm?
Will the supply RCD be enough protection?
Do I need to ‘notify’ if done this way? If it is just an extension of the ring main I wasn’t sure if this was absolutely necessary or not. Obviously it is poor practice. Minor works?
Other considerations:-
Earthing system in house is TN-S
There will be no gas / water or extraneous metal in the shed.
I imagine in the upcoming winter months he will be having a heater on and the treadmill at the same time. 3000w / 230v = 13.04A, that is before taking into account voltage drop etc, but I can’t see him using both appliances to the max at same time. Giving that the fused spur is limiting him to only 13A I imagine this could be pushing it.
Any suggestions for better way would be great! Feel free to tear my plan apart, I’d rather set him straight with the task that’s required.
Thanks
Planning on wiring my neighbour's summer house which will be 15 metres away from the end of the house (20-25 metres total distance from the supply CU under the stairs).
Need some advice on which option would be the most SAFE not just the quickest, cheapest method etc. If it costs more to be done properly then that’s how it will be done.
The electrical needs for the shed are:-
LED lighting
Power for a treadmill 1000w and heater 2000w
The situation is this - the house has been underpinned and has no access under it for running cables. The CU being where it is means it would be a tricky albeit not an impossible SWA run along the outside of the house, that's before you get to the drop down to the garden trench for the final stretch to the shed. The alternative to running it that way is going out to the wall behind the CU first then down under the driveway to the garden, although this would mean raising a fair few flags. I know this may sound lazy but I don't want to be lifting 5 metres of driveway flags to run the cable under that way, but if that is the best way so be it. Ideally I would prefer not to use a full run of 25 metres of SWA but again, if needs must.
There is a ring main socket situated on the downstairs back room wall adjacent to the rear garden that has a T+E 2.5mm2 coming out to a junction box on the exterior wall directly opposite. This JB is supplying flood lights (which don't work!).
Here's my first thought...
Could I replace the JB on the ext wall for a 13A FCU spur inside a waterproof casing (Doing away with the existing flood light cables) Run a 2.5mm SWA from this, bury it a foot deep along the side of the garden to one metal-clad double socket inside the shed avoiding the need for a sub-CU. Then feed off from this to an additional FCU switch 3A for the lighting circuit?
Here’s where I need guidance?
Will spurring off the downstairs 32a MCB ring main be ok for the distance and load etc?
If so, will SWA 2.5mm be enough or upgrade to 4mm, or 6mm?
Will the supply RCD be enough protection?
Do I need to ‘notify’ if done this way? If it is just an extension of the ring main I wasn’t sure if this was absolutely necessary or not. Obviously it is poor practice. Minor works?
Other considerations:-
Earthing system in house is TN-S
There will be no gas / water or extraneous metal in the shed.
I imagine in the upcoming winter months he will be having a heater on and the treadmill at the same time. 3000w / 230v = 13.04A, that is before taking into account voltage drop etc, but I can’t see him using both appliances to the max at same time. Giving that the fused spur is limiting him to only 13A I imagine this could be pushing it.
Any suggestions for better way would be great! Feel free to tear my plan apart, I’d rather set him straight with the task that’s required.
Thanks
