Switchgear

gnselectricals · Aug 2, 2014

Hi guys after a recommendation for some switchgear iv got a 70mm 4core Swa going in which I'm doubling the cores up as a single phase supply due to voltage drop. Eddys have quoted me on a wylex nhspsf100 which is only good upto 50mm. Ideally I'd like bolt on terminals to lug the 2 parallel 70mms onto. Incoming/outgoing is only 35mm

Cheers

Darkwood · Aug 2, 2014

Not sure what your asking here.... you know what lug size you require then ask for some switchgear that can accept 2 x 70mm's per connection.

PS don't go for cheaper options here as you get what you pay for and you will struggle with lackm of room, poor design etc ....Ive just had to tail up a 400amp Proteous incomer and jeeze how poorly its designed and flimsy structurally it was clearly there decide team has never had to try fit 185mm's into their gear (I covered for someone so not my order or job).

Lastly consider an extension box and do an adiabatic equation for your earth if your using 4 cores as a 1ph supply as I doubt the swa it will satisfy the 140mm core csa you have achieved so better to run a separate earth or 2 separate swa's as parallel feeds.

Also ask your supplier if wylex provide an upgrade kit for the 35mm termination terminals ... many brands have some form of kit that allows these to be increased for larger cables... again because of the size incomer you have the isolator may be too tight on space as its designed for a 35mm max so consider this and your glanding point of entry too, this will be the difference between been physically able to terminate it and not.

Engineer54 · Aug 2, 2014

I can guarantee the steel armouring won't be able to satisfy requirements and that if any main bonding is going to take place at load end of this cable, it won't comply anyway. A suitably sized separate earth conductor is going to be a must, especially over what must be a considerable distance, if you need 140mm of copper to supply a 100A or less load!!! lol!!