I'm a new member...hello.
The project is the installation of a supply to a workshop / shed & a second shed in the back garden of a residential property. The property is a ground floor maisonette with solid concrete floors.
I have made a sketch of the site but I believe I cannot add it at this stage, so I will describe it:
The consumer unit is located in a cupboard in the middle of the property: single phase with equipotential bonding, metal cased c/u. The route of the internal cable, runs from the cupboard to the bathroom, under the bath, through to a bedroom to the point out of the external wall to the back garden. I have dug a trench to the shed for the SWA cable. The length of the internal wiring to the point it exits the property is a total of 11m approx. The length of the trench to the workshop / shed is 12 metres. I plan to install a garage / builders RCD unit in the shed to provide for 2 plug sockets, 4 inside lights & 4 outside lights & then back out to another trench 1.5 metres long to the second shed which requires 4 plug sockets & 4 inside lights.
The first shed is primarily used as a workshop for using woodworking small wood tools...the biggest being a 1600 Watt sliding cross cut mitre saw, I have several small saws & drills but only one will be used at a time. There will be no lathe! I will need to run a laptop at the same time as a tool sometimes & the lights will need to be on, I will use low energy leds. The second shed is for a model train set with a small load. I want to be able to turn on the outside lights located at the shed, from the house.
As a reference I am reading: " Electrical installation work 2nd edition" by Brian Scadden. I am trying to understand but am struggling with working out the size of the cable I need, there is a lot of information to take in - I understand the concern about voltage drop with longer cable runs & I would prefer to upscale the size of the cable to ensure it is big enough. Where I am struggling more is working out the size of the load? I have looked at "Doncaster cable" website which has a cable size calc & also TLC direct which has one too. I first thought I would need 2.5mm SWA cable, then 4mm but now thinking bigger? The SWA will sit in the trench on a bed of sand & will be covered by warning tape. However, I need to run a type of conduit too, to allow for a cable to the light switch at the house?
Other information: Ambient temperature assumed at under 30 degrees. T&E 3C cable from the property c/u to the outside wall to be the same size as the SWA cable to the shed. The connections within the IP rated junction box will be earth continued ( if that's the way to say it!?). At the shed the SWA cable will be finished in a junction box & the cable to the RCD unit will be fed through the back of the box. Inside the shed I am assuming I need metal clad boxes/fittings with metal conduit?
I will try to answer any questions asked to provide an accurate picture.
Thank you.
The project is the installation of a supply to a workshop / shed & a second shed in the back garden of a residential property. The property is a ground floor maisonette with solid concrete floors.
I have made a sketch of the site but I believe I cannot add it at this stage, so I will describe it:
The consumer unit is located in a cupboard in the middle of the property: single phase with equipotential bonding, metal cased c/u. The route of the internal cable, runs from the cupboard to the bathroom, under the bath, through to a bedroom to the point out of the external wall to the back garden. I have dug a trench to the shed for the SWA cable. The length of the internal wiring to the point it exits the property is a total of 11m approx. The length of the trench to the workshop / shed is 12 metres. I plan to install a garage / builders RCD unit in the shed to provide for 2 plug sockets, 4 inside lights & 4 outside lights & then back out to another trench 1.5 metres long to the second shed which requires 4 plug sockets & 4 inside lights.
The first shed is primarily used as a workshop for using woodworking small wood tools...the biggest being a 1600 Watt sliding cross cut mitre saw, I have several small saws & drills but only one will be used at a time. There will be no lathe! I will need to run a laptop at the same time as a tool sometimes & the lights will need to be on, I will use low energy leds. The second shed is for a model train set with a small load. I want to be able to turn on the outside lights located at the shed, from the house.
As a reference I am reading: " Electrical installation work 2nd edition" by Brian Scadden. I am trying to understand but am struggling with working out the size of the cable I need, there is a lot of information to take in - I understand the concern about voltage drop with longer cable runs & I would prefer to upscale the size of the cable to ensure it is big enough. Where I am struggling more is working out the size of the load? I have looked at "Doncaster cable" website which has a cable size calc & also TLC direct which has one too. I first thought I would need 2.5mm SWA cable, then 4mm but now thinking bigger? The SWA will sit in the trench on a bed of sand & will be covered by warning tape. However, I need to run a type of conduit too, to allow for a cable to the light switch at the house?
Other information: Ambient temperature assumed at under 30 degrees. T&E 3C cable from the property c/u to the outside wall to be the same size as the SWA cable to the shed. The connections within the IP rated junction box will be earth continued ( if that's the way to say it!?). At the shed the SWA cable will be finished in a junction box & the cable to the RCD unit will be fed through the back of the box. Inside the shed I am assuming I need metal clad boxes/fittings with metal conduit?
I will try to answer any questions asked to provide an accurate picture.
Thank you.
