Cable grommets on IP55 junction box

DonnyDave

I'm looking at getting some of these IP55 junction boxes from Screwfix:

Round 4-Terminal Junction Box with Knockouts Grey 65mm

Do you just push the cable through the gromet and it will pierce a hole and remain watertight?

Also, will the gromets that come with it accept flat twin and earth, or is round cable/flex only?

vaio

wouldn't have thought that would be IP55 once you'd added cables.....I'd replace the grommets with proper stuffing glands

Owain_Moneysaver

round cables only, and not suitable for mains use as the cover can be removed without using a tool.

For mains use something like this and use the glands shown on the same page rather than relying on the rubber seals.

T&E cable isn't suitable for exterior use anyway.

DonnyDave

Thanks Owain Moneysaver, it's interesting what you say about these units not being suitable for mains use because they can be opened without a tool.


The reason I ask about this is because in the loft there is condensation forming on the inner-side of the felt and there are a few junction boxes. I'd like to replace them with waterproof ones (hence the requirement for acceptance of T&E).

Owain_Moneysaver

the box recommended in #3 would be adequate. Remember that the cables must be clipped. and the box screwed. to joists, so the cables can't be pulled out of the box.

If the cables or box are lying loose then glands must be used.

DonnyDave

Thanks again Owain Moneysaver.

I think that those boxes will work with the cables run in/out the underside with a drop-loop to allow water run-off if they come from above.