40mm to 20mm gland reducers

[johnboy4809]

Hi all, our summer house had a FuseBox consumer unit fitted last year and the guy who did the work has retired. nothing wrong with the install however my wife wants an outside light fitted and would be best to run some white 20mm conduit to the CU as it would blend in when we decorate. the CU only has a 40mm knockout on the side. is there a 40mm to 20mm reduction gland or is it best to drill your own 20mm hole. Just interested in best way and will be hiring in an electrician but locals are so pulled out with work atm

 

[littlespark]

best to drill your own 20mm.
Sharp holesaw, not too much pressure or it’ll take out the 40. Unless you can drill through a bit not near a knockout.

For aesthetics, I try to bring all surface cable in on the same side of the unit… usually the bottom.

 

[DPG]

Or a chassis punch. Oops, here we go again

 

[johnboy4809]

best to drill your own 20mm.
Sharp holesaw, not too much pressure or it’ll take out the 40. Unless you can drill through a bit not near a knockout.

For aesthetics, I try to bring all surface cable in on the same side of the unit… usually the bottom.

Ok cheers, just wandered if there was a gland solution rather than drilling,

He ran everything on the outside in conduit so all you see is the sockets so none of the knockouts have been used, just cant run externally for this

 

[littlespark]

you can get 40 to 20 reducers (or is it 38mm??) but not so common now, so expect a high price. Also look quite bulky... and you'de need a matching locknut

 

[Marvo]

I'd suggest just buy a 40mm compression gland (I think they're known as stuffing glands in the UK) that will accept the 20mm conduit instead of using the usual male adapter. Normally I'd have suggested a much cheaper nylon gland but he link I gave is for a steel gland because I'm not sure about your fire regs in the UK.

 

[WallaceP]

M40 to M20 Reducer (Sold in 1's) - https://www.cef.co.uk/catalogue/products/1030542-m40-to-m20-reducer?gclid=CjwKCAjwzJmlBhBBEiwAEJyLu92nFGUv-CdF70fj1SLOjrsaWAqlOZ8NDgGbT4oXfHr_BIxACaB-mhoCM5MQAvD_BwE&gclsrc=aw.ds

M40 Male To M20 Female Nylon Reducer

M40 Male To M20 Female Nylon Reducer

www.cablecraft.co.uk

there is a steel or pvc option
you would need a M40 lock ring too. I would suggest drilling an 20mm hole first and if it fails that being your backup plan.

 

[ipf]

The above is a good way of looking it (drilling for a spark).....but are electrical regulations being taken into consideration?

 

[nicebutdim]

The above is a good way of looking it (drilling for a spark).....but are electrical regulations being taken into consideration?

OP states in last sentence that they'll be hiring a spark, so I'd like to think regulations will be adhered to.

I'd also imagine the spark will drill a 20mm hole, without so much as a thought about unnecessary, expensive and bulky adaptors.