Old house overhead line, combined neutral earth, garage SWA type advice

[Theauldhoose]

Hi all,

Looking for some advice please, based in central Scotland, have an old house circa 1908, has an overhead line supply, which is then connected into a single concentric core SWA, looks to be circa 25+mm2 live core, with the armored surround acting as a neutral and then joined to the earth lines where it exits the isolator fuse.

I’ve just built a large garage workshop, will be using mostly 13a kit, but have welder / car ramp / compressor / 6 strip lights (not all at the same time) but expecting to average circa 8-20a peak draw, looking to use 10mm2 cable, but how many cores?

Do I go 2 core and fit a earth rod near the garage (steel frame)?

Or do I fit 3 core and run the combined earth / neutral from the house to the garage?

Finally whilst the garage is only 12m from the house, the swa run will be 35m end to end, any issues expected?

Any advice greatly appreciated?

Cheers

 

[Fleeting]

Can you show this supply cable because swa cables are not used for concentric supplies.
No you cannot combine the earth and neutral (PEN).

 

[Theauldhoose]

Y

 

[Fleeting]

That is a concentric cable and you have no business taking the service head apart. Whatever it is you intend to do is clearly outside of your competence level and you should contact an electrician.

 

[monkey5]

You shouldn't be touching that, and it's not SWA. You need an electrician.