3 phase

[keniff]

What's the norm on a 3 phase Submain in regards to swa and earthing, I'm looking at 25mm swa but not keen on using the armour as earth, (it works out ok size wise) I normally use an extra core for earth on single phase but 5 core swa seems a bit thin on the ground anyone have fors and againsts for usin the armour?

 

[ipf]

If it satisfies, what's the problem?

 

[D Skelton]

I'm assuming you know how to make off a gland correctly (I mean that in a completely non patronising way). Done right there's no problem

 

[Thefailsafe2012]

If your really worried pull in a separate single with it mate!

 

[keniff]

Yeah it's quite a long run underground, I know how to gland etc its not that so much it's if it's damaged underground and a bit of water gets in the armour and rots away, I'm just belts and braces I suppose lol what's the best way to terminate the earth if using the armour I normally go for serated washers and bolts I don't think they make pirahna nuts that big!

 

[Bobster]

It'll only be 32mm not exactly big.

what wrong with using the banjo with a brass nut and bolt?

 

[D Skelton]

Pirahna do 32mm nuts

Nothing wrong with a correctly fitted banjo either!

Edit: Beaten to it

 

[keniff]

That's what I mean bango nut and bolt, thanks guys

 

[Bobster]

Make sure you use brass.

Steel bolts will corrode overtime.

 

[HandySparks]

If you're worried about damage to the cable on installation or backfilling of the trench, why not put a duct in first and just pull it through?

 

[keniff]

That's the plan handy, but you never know if a stone gets in etc and gets a slight slit in the sheath just go carefull I suppose, softly softly catchy monkey

 

[KAS1]

Use the SWA as earth no problem

 

[AndyOz]

The use of the SWA is one of the big differences in common practice between domestic and commercial/industrial installs. Using the armour is common practice as earthing conductor although recent installs I have been involved with supplementary has been specified within switch rooms. This provides extra protection on ladder and cable tray.

 

[Knobhead]

If you're worried about damage to the cable on installation or backfilling of the trench, why not put a duct in first and just pull it through?

How are you going to damage a cable with back fill if done properly?
Do the job properly, use the armour, gland and earth the end correctly. Can’t be any simpler really.

If you’re worried you can carry out a sheath test. But if it fails you’re shafted anyway.

 

[GLENNSPARK]

What's the norm on a 3 phase Submain in regards to swa and earthing, I'm looking at 25mm swa but not keen on using the armour as earth, (it works out ok size wise) I normally use an extra core for earth on single phase but 5 core swa seems a bit thin on the ground anyone have fors and againsts for usin the armour?

look, if the armourings are adequate then whats the need for the spare core?...
and i say spare core as that`s exactly what it would be.....doing nowt....lol...

 

[Silly Sausage]

How are you going to damage a cable with back fill if done properly?
Do the job properly, use the armour, gland and earth the end correctly. Can’t be any simpler really.

If you’re worried you can carry out a sheath test. But if it fails you’re shafted anyway.

I better off not go back and some tests on my garden jobs!

 

[GLENNSPARK]

I better off not go back and some tests on my garden jobs!

na...sod it....it`l be right...lol...
everything`s holding....isn`t it?..lol...

 

[Knobhead]

I better off not go back and some tests on my garden jobs!

Still doing the illicit horticulture then?

 

[44ALLAN]

What's the norm on a 3 phase Submain in regards to swa and earthing, I'm looking at 25mm swa but not keen on using the armour as earth, (it works out ok size wise) I normally use an extra core for earth on single phase but 5 core swa seems a bit thin on the ground anyone have fors and againsts for usin the armour?

Single phase SWA...........3 core dedicated earth.
3phase/N. SWA.........5 core with dedicated earth( neutral distributed or not).
That's me every time.....bwtfdik
Solid 6mm brass bolt and nut earth throughout.

Nothing wrong with either method mate...........properly installed lol

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