Terminating SWA Cable.

[grantr37]

I wounder if anyone would be so kind as to offer some advice. It's not something I'm actually wiring up, it's just a little theory project to do with college.

If I want to come from a breaker switch in a distribution board, and run a supply along a cable tray in SWA cable to a 32amp three phase and earth interlocked socket. From looking in tables I have figured I'm going to need to use 4.0mm SWA cable and obviously I'm going to have to terminate the cable at each end using glands. What I'm not sure about is how many core cable should I use, as should I use the outer steel wires of the cable as the CPC Earth), which would mean I could use 4 core cable, or should I use 5 core cable, and one of the cores of the cable as the CPC as well as connecting the outer steel wire sheath to earth?

The other thing I'm not too sure about, if I can use the outer of the cable as CPC, when I terminate it to the interlocked socket, this has a plastic housing. Would I therefore use one of those washers around the gland with a the little bit that sticks out and make a connection to this and then take this in to the earth terminal?

Thanks for any advice offered

David

Hello David

Yes use earthing washers at the end of steel wire armour cables, fix the earth wire to them using either a crimped on yellow eyelet terminal (tag/crimp connector) and use a suitable bolt (copper if possible as some people don't like roofing bolts to be used for this)or if none available/practical to get in reasonable timescale, twist the wire round the eyelet and then set it with solder, if you have a small bit of heatshrink then you could slide that along the earth wire first, do the connection then slide it back over the connection and shrink it...


you will also hear the earthing washers being referred to as "Banjos" and "Frying pan handles" by Electricians...due to their shape


Use an Earth core as a CPC (circuit protective conductor) and also bond/connect the steel armour to earth as well...

 

[paul wild]

Good info Grantr 37

 

[JONOXNAM]

Pnuts are also excellent..

 

[Specialist]

Guys: This is getting silly, the original post is something like 3 years old & was accidentaly resurrected by trev due to a browser problem.

 

[Specialist]

You must be using google chrome then.:sailor:

Cheers mate: Any work around for the problem ?