Bonding to SWA armour - not able to gland

cymroaur · Aug 28, 2012

Hi all,

Been to look at a job in a chalet. Nice shiny 16mm earth from the CU to an earth terminal, sh**e 4mm oxidized to f*** from the terminal to the armour of the incoming, looped to the 'loop out' SWA going onto the next chalet (sorry, didn't take a photo). Anyway, the site owner has said that maintenance crew will be onto it within a few days, which the customer reckons will be next year! So in the spirit of getting the job done quickly, he's asked if I could do it. So my question is: What's the best way of attaching to the armour, without having the cable loose to slip a gland over it. Jubilee clip? Earth strap? Is there a product out there which I don't know about?

P.S. The property is empty for a couple of weeks, so have switched off for now.

Thanks in advance.

johnboy6083 · Aug 28, 2012

If it must be done with the feed to other caravans left live, then constant tension springs are the way to go with this I think. Strip the sheath off the SWA and then wrap the spring once around the armour. Insert the end of your new earthing conductor onto the spring and then continue wrapping the spring around. I sometimes double the conductor over 2 wraps to ensure a good contact. Then seal the whole lot with self amalgamating tape.

Engineer54 · Aug 28, 2012

Is this a DNO or private installation.... Taking it as private, you can provide a ''constant pressure spring'' earthing point with a braided earth conductor to the SWA. Do not, and never use a ''jubilee clip'' direct to the steel wire armouring, relying on the cable bedding and insulation if tightened to excess now, or in the future by others.....

lamb · Aug 28, 2012

CEF do the constant force springs in a kit with different sizes. also has jubilee clips in the kit.

Philpot · Aug 28, 2012

These "Constant force springs" have obviously passed me by. My cable jointing experience was a very long time ago but you are never too old to learn. I can think of a particular application of these devices that would have saved me a lot of time and money.

Thank again for the post
Phil