Workshed trunking and cable.

[toptec]

Morning Chaps.

Workshed built, now measuring up for SWA cable to run from the house CU under a couple of paths to the shed's seperate CU. I will be running three double switch sockets, one main interior light and possible two smaller floods on the outside. What sized SWA would I need?

As for the trunking from the shed CU to the sockets should I use metal or can I use plastic?

 

[Chri5]

Morning Chaps.

Workshed built, now measuring up for SWA cable to run from the house CU under a couple of paths to the shed's seperate CU. I will be running three double switch sockets, one main interior light and possible two smaller floods on the outside. What sized SWA would I need?

As for the trunking from the shed CU to the sockets should I use metal or can I use plastic?

* Please indicate the length of SWA required from house CU to shed.

* Please confirm that the sockets will be a 32a ring and the lights a 6a radial

* Plastic would be easier, since you won't have to provide earth continuity, which metal would require. If the enviroment is harsh and mechanical bashing of trunking is likely, then metal.

 

[toptec]

* Please indicate the length of SWA required from house CU to shed.

18 metres.

* Please confirm that the sockets will be a 32a ring and the lights a 6a radial.

Absolutely - Fitted by a quality sparky

* Plastic would be easier, since you won't have to provide earth continuity, which metal would require. If the enviroment is harsh and mechanical bashing of trunking is likely, then metal.

All the trunking will be running through studs, the lighting circuit will be clipped to the rafters. I would find it easier to manoeuvre the trunking around the corners and deal with the drops if it were plastic. There will be no bashing around.

Thank you for the advice.

 

[ban-all-sheds]

Wouldn't conduit be a great deal easier than trunking?

Will there be thermal insulation applied after the wiring is done, and if so have you taken account of this when sizing the cables?

Will internal boarding be applied after the wiring is done, and if so have you taken account of the rules for concealed cables?

Do you have the ability to test your final circuits, measure Zdb etc?

Have you told your local council about this work?

 

[Chri5]

Cable Type Twin and Earth SWA (3 Core)
Underground
Ambient Temperature 15 °C
Number of Circuits 1
Power 9 kW
Voltage 230 Volts
Length 18 metres

Required Cable Size 6 mm
Voltage Drop 4.79 Volts.
Percentage Drop 2.1%
Current Load 39.0 Amps
Max Cable Load* 46.2 Amps

 

[toptec]

Wouldn't conduit be a great deal easier than trunking?

Possibly - I will have a look at that.

Will there be thermal insulation applied after the wiring is done, and if so have you taken account of this when sizing the cables?

No insulation being fitted.

Will internal boarding be applied after the wiring is done, and if so have you taken account of the rules for concealed cables?

No internal boarding

Do you have the ability to test your final circuits, measure Zdb etc?

Why would I wanna do that when I am employing an electrician to do the work I am not qualified for?

Have you told your local council about this work?

You feel I need to? -

So 6mm twin and earth SWA then Chris5

 

[ban-all-sheds]

Do you have the ability to test your final circuits, measure Zdb etc?

Why would I wanna do that when I am employing an electrician to do the work I am not qualified for?

Because the questions you were asking did not indicate that you are employing an electrician.

If you are employing one then you must ask him all these questions, as his name & signature will be on the certificate.

Have you told your local council about this work?

You feel I need to? -

The work is notifiable, so the legal requirement is for it to be notified after the event if it's done by a Competent Person, or in advance if it's not...

The existence of a cabled building might be hard to conceal in the future, and people might ask in the future to see a Building Regulations completion certificate.

So 6mm twin and earth SWA then Chris5

That's a design decision which must be made by your electrician.

 

[toptec]

Do you have the ability to test your final circuits, measure Zdb etc?

Why would I wanna do that when I am employing an electrician to do the work I am not qualified for?

Because the questions you were asking did not indicate that you are employing an electrician.

* Please confirm that the sockets will be a 32a ring and the lights a 6a radial.

Absolutely - Fitted by a quality sparky

I apologise if that was not plain enough but due to an injury my electrician is unable to deal with minor questions like the type of cable right now. He and I have already re-wired my bungalow. I have previously bought all the cable and associated materials for the rewire. I understand and agree with all that you say regarding the signing off of the work but I wanted to restrict my question to that of the cable and conduit.
Thank you for your well intentioned advice.