Sorry if this is the wrong location, please move or direct me to correct place if so!..
In short, I'm wondering if anyone could offer comments or advice on my intended electrical run to a garden building?
From my consumer unit in the garage (main household box) there is already a 32A MCB running 4mm cable to a junction box which then runs 4mm SWA underground to shed (this was installed a while back when I built the shed by a qualified electrician).. This had its own consumer unit with a separate lighting and socket circuit. I say 'had' because I have since demolished the shed and disconnected the 4mm at the main household box, leaving the cable run to the end of the SWA (but no longer live of course)
The electrician has told me he is happy for me to wire up a new garden building while the whole thing is dead and he will carry out a thorough inspection & test before I board up the walls etc.. so it is all still exposed.
So my intention is to do the following, please advise!!..
- Not touch the main CU, the 32A MCB (currently not connected to anything) is part of a 63A RCD controlled bank
- Maintain the 4mm T+E from CU to first junction box (about 10m linear length)
- At first junction replace the existing SWA with 6mm (in-case the garden building requires something heavier duty in future, since the SWA is buried I don't want to risk needing to dig it up 10 years down the line) SWA is about a 10m run
- Install second junction box at garden building, continuing with 4mm T+E for a short length to secondary CU
- Connections at junction boxes will be proper SWA glands and WAGO connectors
- 32A RCBO into the garden building CU, splitting into 5 fused circuits
The 5 circuits being..
1 - 2000W (MAX) AC Unit (16A / 2.5mm T+E)
2 - Garden room sockets, 24m² (16A / 2.5mm T+E)
3 - Shed sockets 8m² (16A / 2.5mm T+E)
4 - Lighting circuit (6A / 1.5mm T+E)
5 - Soffit extractor fan circuit (6A / 1.5mm T+E)
All above will be radial circuits with cable direct in insulated walls
My theory being that the AC could be in use at any time, drawing a maximum of 10A.. leaving 22A for a garden room/office + shed + ancillaries
I'm sure its clear from the above that I am no electrician, to re-iterate this will all be dead during my work and will be fully inspected and tested before connecting back to power!
One thing I'm definitely not sure on is the RCBO I'm putting in the garden room CU, is this correct or can it just be a standard MCB (since the circuit is RCD protected at the main CU?)
In short, I'm wondering if anyone could offer comments or advice on my intended electrical run to a garden building?
From my consumer unit in the garage (main household box) there is already a 32A MCB running 4mm cable to a junction box which then runs 4mm SWA underground to shed (this was installed a while back when I built the shed by a qualified electrician).. This had its own consumer unit with a separate lighting and socket circuit. I say 'had' because I have since demolished the shed and disconnected the 4mm at the main household box, leaving the cable run to the end of the SWA (but no longer live of course)
The electrician has told me he is happy for me to wire up a new garden building while the whole thing is dead and he will carry out a thorough inspection & test before I board up the walls etc.. so it is all still exposed.
So my intention is to do the following, please advise!!..
- Not touch the main CU, the 32A MCB (currently not connected to anything) is part of a 63A RCD controlled bank
- Maintain the 4mm T+E from CU to first junction box (about 10m linear length)
- At first junction replace the existing SWA with 6mm (in-case the garden building requires something heavier duty in future, since the SWA is buried I don't want to risk needing to dig it up 10 years down the line) SWA is about a 10m run
- Install second junction box at garden building, continuing with 4mm T+E for a short length to secondary CU
- Connections at junction boxes will be proper SWA glands and WAGO connectors
- 32A RCBO into the garden building CU, splitting into 5 fused circuits
The 5 circuits being..
1 - 2000W (MAX) AC Unit (16A / 2.5mm T+E)
2 - Garden room sockets, 24m² (16A / 2.5mm T+E)
3 - Shed sockets 8m² (16A / 2.5mm T+E)
4 - Lighting circuit (6A / 1.5mm T+E)
5 - Soffit extractor fan circuit (6A / 1.5mm T+E)
All above will be radial circuits with cable direct in insulated walls
My theory being that the AC could be in use at any time, drawing a maximum of 10A.. leaving 22A for a garden room/office + shed + ancillaries
I'm sure its clear from the above that I am no electrician, to re-iterate this will all be dead during my work and will be fully inspected and tested before connecting back to power!
One thing I'm definitely not sure on is the RCBO I'm putting in the garden room CU, is this correct or can it just be a standard MCB (since the circuit is RCD protected at the main CU?)