Maximum usable size of SWA for garage run?

[Deluks]

In reference to:

//www.diynot.com/forums/viewtopic.php?t=21629

Is there a maximum type of cable I can use for this application? I may be able to get some cheap 4 core SWA, but it will be massive, like 25mm or something silly, (20mm overall diameter). Will this be usable, or will it give me problems?

 

[plugwash]

theres nothing stopping you using large sizes and on a long run you may have to.

you need to give terminating it a lot more thought with cables that size though.

 

[Big_Spark]

Deluks, with all due respect, call an electrician and get the job done right, you will need it certified and you cannot do this, so you may as well bite the bullet and call in someone who can.

 

[mapj1]

Such work should be notified to building control who will charge to inspect it, but there is nothing to stop anyone doing anything to their electrics, but for 'notifiable work' then you need to convince the man from the council you are doing it OK. * 25mm sounds a bit difficult to bend -I'd go straight into metal boxes at each end, and then step down to something thinner.
Don't forget to get the right size glands, and to make sure the armour is well earthed.

* PS And most councils charging practice makes it more worthwhile to DIY the bigger the job is, while discouraging the notification of small jobs.

 

[Steve]

I saw a shop once, the meter was at the front, and the distribution boards were in the back room. They ran a piece of 25mm 4 core SWA across the ceiling of the shop, then diagonally through the back wall and curved through another wall, running diagonally, and curled into the distribution board. It looked a mess as it couldnt be clipped to any of the walls. I dont see how terminating it is a problem though, it just uses glands like small SWA doesnt it?

 

[Big_Spark]

The fact that 25mm SWA has been even mentioned seriously means he doe not know what he is doing. This is not a bootlace cable, it needs careful and considered handling or you can do yourself a serious injury with it for starters, but most importantly this needs to be correctly terminated, and I doubt he knows how to terminate a small SWA, let alone how to terminate one like this that would require BW32 glands, I don't think he realises just how difficult a task he would be taking on.

Also, for what he wants to run, even taking the distance into account, 10mm SWA would be sufficient and some.

I stanbd by my first recommendation and that is call in a spark.

 

[andy]

The fact that 25mm SWA has been even mentioned seriously means he doe not know what he is doing. This is not a bootlace cable, it needs careful and considered handling or you can do yourself a serious injury with it for starters, but most importantly this needs to be correctly terminated, and I doubt he knows how to terminate a small SWA, let alone how to terminate one like this that would require BW32 glands, I don't think he realises just how difficult a task he would be taking on.

Also, for what he wants to run, even taking the distance into account, 10mm SWA would be sufficient and some.

I stanbd by my first recommendation and that is call in a spark.

but like he said... he can get the thicker stuff cheaper. so why not got OTT now then you wont have to upgrade in the future... and putting in a larger size than needed is not a bad thing, unlike using 1.5mm armourd to a shed 50 metres away

 

[Big_Spark]

Andrew, putting in a 25mm SWA to feed something that will have a max load of around 20A is simply daft, and the only reason he would be able to Buy 25mm SWA cheaper than smaller sizes is if it is stolen.

You will not convince me of any other legal way the cable could be obtained as there is not one.

 

[Deluks]

Andrew, putting in a 25mm SWA to feed something that will have a max load of around 20A is simply daft, and the only reason he would be able to Buy 25mm SWA cheaper than smaller sizes is if it is stolen.

You will not convince me of any other legal way the cable could be obtained as there is not one.

Ebay!
I didn't get the cable in the end (got outbid, bah!) but I'm always on the lookout. You be suprised what gets thrown out by building contractors. There was a skip outside my workplace recently that was used by the building company working in a nearby shopping Centre. They've finished working now but the last week they were there I fished some usable stuff from the skip. 23 metres of 2 core SWA, 30 metres of 6mm 3 core SWA leftover on the drum, and about 15 brand new knauf insulation slabs. Unfortunately the cable was neither long or thick enough for my needs but it will be going onto eBay as soon as I get a spare minute. The insulation though, is perfect for my music room and has saved me a few quid.

Needless to say, I will be getting a qualified sparky to connect everything, I'm just acquiring materials at the moment before I commence work.

cheers 4 all replies anyway
Del

 

[ban-all-sheds]

Also, for what he wants to run, even taking the distance into account, 10mm SWA would be sufficient and some.

If it's 4-core, 20mm O/D, it probably is 10mm²...

 

[Deluks]

6mm 3 core, well that's what it said on the drum, the cable itself reads (2.5 x 3) is that the same thing? (It's about the same thickness as 4mm 3 core)

 

[andy]

6mm 3 core, well that's what it said on the drum, the cable itself reads (2.5 x 3) is that the same thing? (It's about the same thickness as 4mm 3 core)

i think 2.5x3 is what it sounds like.... 2.5mm^2 3 core

 

[Big_Spark]

2.5x3 means that it is 3 core 2.5mm .

That will be too small for what your trying to do due to volt drop.

 

[HDRW]

6mm 3 core, well that's what it said on the drum, the cable itself reads (2.5 x 3) is that the same thing?

No! Sounds like they rewound some spare 2.5mm onto an empty drum that had previously contained 6mm cable.

Cheers,

Howard