Do I need grommets on earthed conduit

[turningtim]

Sparky's been over and is happy with chasing, cable routes etc and sorted all the rest, Ive but to day been on with the lights.

All the switches are in slim (18mm??) back boxes, these are bolted and clamped to metal conduit running to the ceilings. Its all earthed via the back box but no grommets -don't see how there could be given the clamps. Even the black enamel has been scraped off and I get a zero ohms reading of a digital multimeter between earth and back box or conduit.

Is that ok or should i break out the plaster trim the conduit, replace the boxes and add grommets? Sparks is on holiday this week and I'd like to press on but not going to hassle the guy while he's on leave

 

[plugwash]

The proper way to join conduit to a backbox is to use purpose designed conduit adaptor peices. there are a couple of different styles of theese (you can have a male adaptor and a locknut or a female adaptor and a bush). Presumablly this is what has been done in your case, post pics if you are unsure.

should i break out the plaster trim the conduit, replace the boxes and add grommets?

No, then the metal conduit would not be earthed.

 

[ban-all-sheds]

you can have a male adaptor and a locknut or a female adaptor and a bush.

Isn't modern medical science wonderful?

 

[turningtim]

I had a look at the TCL catalogue and the look similar to threaded nipples, so now I don't know if in need an electrician, a plumber or a gynaecologist!

Seriously tho... its an oval section pressed steel conduit not the really rigid threaded stuff, its dead easy to bend by hand and the "seam" isnt welded must be the 1960's equivalent of 20mm oval plastic, I'll see if I can get some photos over today

 

[wingcoax]

When yoy say clamped Do you mean with a purpose made clamp? If so it will probably be rounded off inside ,so you don't need grommets. Your sparky should know, ask him.

 

[ban-all-sheds]

so now I don't know if in need an electrician, a plumber or a gynaecologist!

Hormone treatment will suffice.

Seriously tho... its an oval section pressed steel conduit not the really rigid threaded stuff, its dead easy to bend by hand and the "seam" isnt welded

Ah - that quality stuff....