swa problem

[gasman1987]

hello,
I have layed a 10mm 3 core swa cable underground
(live neutral earth)

The problem is i damaged the cable with a shovel. I removed the steel armour and insulation to expose the 3 inner cores which are all intacked.
I do not want to cut the 3 inner cores just weather proof and maintain continuity throughout the steel wire armour which is not used as the earth

How do i repair

 

[sparkticus]

http://www.tlc-direct.co.uk/Products/SWJK1.html

Use just the joint shell and the resin, discard the connectors.


I have to say that while you don't have to use the outer armour as an earth conductor, it is very bad practice not to earth it at least at one end.

If a nail (for example) enters the cable it potentially could make the armour live!!!

 

[sparkticus]

http://www.tlc-direct.co.uk/Products/SWJK2.html

Sorry, please use this link for 10mm SWA

 

[Spark123]

Not just bad practice, it will not comply with the IEE regs and is dangerous.

 

[Paul_C]

You could use a resin-filled joint kit in order to maintain the armor continuity and provide the necessary sealing for the whole joint. No need to cut the individual conductors to use one of these:

http://www.tlc-direct.co.uk/Main_Index/Cable_Accessories_Index/Joints_Resin_Filled/index.html

Edit: Looks like I took too long locating the right link!

 

[gasman1987]

sorry, the steel is connected to earth at both ends. after this work is competed what checks should a sparky undertake.
continuity and resistance ??????????

 

[sparkybird]

yes, earth continuity (r1 + r2), then insulation resistance between all 3 conductors (and the SWA as it's earthed. Finally the live tests - earth fault loop impedance and RCD trip times (if circuit has an RCD)

SB

 

[gasman1987]

approx how much to test that cable and also a safety check of the house.
it's a 2 bed house.

 

[sparkticus]

sorry, the steel is connected to earth at both ends. after this work is competed what checks should a sparky undertake.
continuity and resistance ??????????

What is the SWA cable supplying? Is this a sub-main?

What is your earthing arrangements at the supply? TT? - TN-S? TN-C-S?

 

[gasman1987]

main earthing is TN-C-S and it's supplying a garden shed
shed fuse board(ring main on a 20amp braker and two lights on a 6amp in shed)
house -main fuse board 40amp

 

[sparkticus]

approx how much to test that cable and also a safety check of the house.
it's a 2 bed house.

How can anyone answer that with any accuracy without seeing the details?

 

[sparkticus]

it's a tncs and it's supplying a garden shed

I was afraid of that. You should get an experienced electrician in for this.

Is the garden shed made of metal by chance?

 

[gasman1987]

its a brick built shed with a metal tile effect roof

 

[gasman1987]

How can anyone answer that with any accuracy without seeing the details?[/quote]

sorry, i no it's a silly question.I thought people on hear might have a idea,,Price range

 

[sparkticus]

You have to be very careful exporting a TN-C-S earth.
In certain fault conditions (loss of neutral conductor) you can end up with live extraneous metal. In some cases it is wise (probably not is yours) to not export a TN-C-S earth outside of the main dwelling and a TT arrangement (with RCD) is used instead. I am not saying that you must do that but you really should have this looked at by an experienced electrician first.