Earthing imperial conduit, and trunking

Jul 13, 2013 13 Replies

Hi



Does anyone know from whence can be obtained the screws for earthing imperial conduit back boxes? They have a slightly raised part of the back face and a tapping to accept a screw.



It might be 2BA or would that be the faceplate screws?



Also, any supplier of PVC trunking (50mm +) in 2m lengths by mail order? Screwfix only do expensive multipacks by mail order; individual lengths are in store only. I don't want have to get it home on the bus.



Owain



They are indeed BA. You'll find BA thread dimensions online, so just measure the hole. Ebay is a good source of such things in small quantities.

I am not sure, but I suspect that the earth screws are 2BA and the faceplate screws are 4BA.

Want me to ask the old one at work in the morning for you?

How far do you have to go to get home? I bought some 2m trunking and conduit from a shed, strapped it upright in the panniers on my bike [1] and rode about 9 miles home.

[1] the transverse way seemed to have some disadvantages. I also had to choose my route as the shortest way had a 1m 80 bridge!

Those holes are to fix an earthing socket. I did buy a load some years ago. The raised bit is so that the fixing screw sits flush with the back of the box. This fixing screw is supplied as part of the earthing kit. A good wholesaler who stocks conduit would be my first point of call.

The earting socket ties in with what I have read elsewhere. Unfortunately (a) this conduit and the boxes are buried in situ (b) the installers left several boxes completely unearthed.

This is a concrete slab building so I suspect the builders put the conduit in and then poured the roof over it.

Owain

About 7 miles.

I would take a knife with me and cut it up outside the shop to take home, but nowadays that's probably get me arrested for carrying an offensive weapon.

Owain

I needed 2m long, so glue would have been necessary :-) Use a junior hacksaw - it's not that good for stabbing and slashing.

For the 2BA: it's _very_ easy to run in a M5 tap - there's hardly any difference. In fact, in sheet metal, with only a few threads, a M5 screw might well just fit.

Ta. Now off ebay-browsing.

Owain

Probably your best bet. I doubt many wholesalers would have them - conduit went metric a very long time ago.

To answer my own question, discount-electrical.co.uk do 3 metre lengths and it comes delivered by Tuffnells.

They did not, however, email me to tell me it was on its way, so just as well I was in and saw the lorry.

Owain

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