Is this acceptable?

[Newbie93]

Hi Everyone.

Im a first year apprentice and would like some opinions please.

I know that lighting is normally wired in 1.5mm and sockets wired in 2.5mm. However, our shed at home has a 1.5mm SWA wired to our small shed for a light.

Would one double or even single socket be able to be wired from this?

The cable is taken from the kitchen ring but is protected by a 13a Powerbreaker RCD Spur so shouldnt trip the house. Also it would only be used every other month for cutting grass or similar activities.

Obviuosly 2.5mm is better but the cable is already wired to shed.

Thanks Guys

 

[telectrix]

you could fit a single asocket to the 1.5mm as long as the cable is protected with a 13A fuse.

 

[i=p/u]

well you can onlu use upto 13A so i dont see why not??? just my opinion but im sure if you in england its a notifiable job and so on

 

[i=p/u]

would he come off the light in 1.5 or 2.5???

 

[Dunc]

I would be wanting to know how far the shed is from the house as volt drop should be considered but it should be okay for 1 single socket if your garden isn't excessively long.

 

[Penance]

I'd do it in 1.5 with 13a protection. No point in spending on 2.5 when feed is 1.5, just IMO tho.

 

[i=p/u]

would the 13A protection that exsists cover this or another 13A fcu???

 

[Adam W]

Yes, volt drop is the one to watch - assuming certain factors a 20m run would have a volt drop of around 8.06v which is higher than the 6.9v allowed for lighting.
10m should be ok though (4.03v).

 

[i=p/u]

would comming off the light in 4mm make in difference in vd??

 

[Adam W]

No because the feed is still in 1.5mm.

 

[Penance]

would the 13A protection that exsists cover this or another 13A fcu???

Sorry not understanding yer question there

 

[i=p/u]

so if vd was to high in this situation, is the only option replacing cable??

 

[Adam W]

You could reduce the rating of the protective device instead, or increase the voltage with transformers, or both.
Reducing the protective device value might make it operate every time the mower is used though.

 

[i=p/u]

its just he said it was already protected from 13A power breaker in house

Sorry not understanding yer question there

 

[i=p/u]

You could reduce the rating of the protective device instead, or increase the voltage with transformers, or both.
Reducing the protective device value might make it operate every time the mower is used though.

well we dont want that happening, so swap cable for larger 1.. i havent looked at electrical stuff in weeks and have tests comming up , need to get my notes back out . i like to know things inside out

 

[Adam W]

That's based on:

VD = (mv/A/m) x Ib x L / 1000
VD = 31 x 13 x 20 / 1000
VD = 8.06v

Assuming the length of the cable is 20m - a figure I just plucked out of the air. Also assuming you'll be drawing the full 13A.

 

[Deleted member 26818]

Whilst the calculations for VD is the same for both types of cable, remember that 1.5mm² SWA has a slightly higher current carrying capacity than 1.5mm² T&E.

 

[Paul.M]

would he come off the light in 1.5 or 2.5???

In this case it would be best to feed the socket first and then spur off to supply the light, all in 1.5mm.

 

[Lou7]

If it's only for the mower should be ok, maximum 6 amp load.

 

[Adam W]

Yeah 6A should be ok (based on several assumptions). I'd use a 10A fuse in the FCU though.