Working with old imperial conduit...

[DNS1]

A mate just moved into a flat and has asked me to sort out a few things with the electrics, mainly convert some single sockets to doubles.

Unfortunately for me, everything has been run in singles in metal conduit without a CPC.

Need to get hold of some backing boxes with the appropriate sized knockouts to take the imperial conduit fittings correctly, but having a hard time finding them at my usual suppliers.

Anyone got any suggestions?

Cheers!

 

[Brendan976]

Use normal back box drill through knockout and if necessary widen hole with cone/step cutter
Ben

 

[DNS1]

I did consider adapting a box, but I'm a bit worried about modifying as it's being used as a cpc.

 

[i=p/u]

Check zs before leaving it be

- - - Updated - - -

Make sure on rcd for your own peace of mind

 

[ipf]

But 20mm is greater than 3/4 inch.

 

[ipf]

A mate just moved into a flat and has asked me to sort out a few things with the electrics, mainly convert some single sockets to doubles.

Unfortunately for me, everything has been run in singles in metal conduit without a CPC.

Need to get hold of some backing boxes with the appropriate sized knockouts to take the imperial conduit fittings correctly, but having a hard time finding them at my usual suppliers.

Anyone got any suggestions?

Cheers!

They used to do 'conversion couplings. Someone may have some, somewhere.
Good luck

 

[DNS1]

Check zs before leaving it be

- - - Updated - - -

Make sure on rcd for your own peace of mind

All on RCD thankfully! Will check Zs when I go back tomorrow

 

[ipf]

Try Neweysonline
Lewden Metric/imperial Adaptor

 

[Engineer54]

But 20mm is greater than 3/4 inch.

If you mean by a knats Pee, your right!! So no problems for the knockouts on back boxes then!!

 

[DNS1]

Bit too big a difference! Especially when relying on the conduit as an earth!

 

[Brendan976]

When I said drill the back box there was no mention of a 20mm cutter, that's why I said you should use a step /cone cutter. Use the largest drill bit that you have, and then use the cutter to the drill to the correct size.

 

[silverfox1]

Bit too big a difference! Especially when relying on the conduit as an earth!

If your using deep 35mm boxes you could use 20mm serrated washers, also known as shake proof washers. . These were always specified at one time on hospital jobs.

 

[i=p/u]

Wee talking about 2mm here ..

 

[Knobhead]

How is the conduit terminated? A coupling and male bush or two lock nuts and female bush? Either way if you’re worried about continuity use an earth tag (banjo as you youngsters call them) with a fly lead. A cone cutter is the best bet to resize the knock out, but as E54 said, it’s a gnats knackers out of size.

Sorry but I’ve promised my imperial stocks and dies to Glenn.

 

[silverfox1]

Wee talking about 2mm here ..

0.75in = 1.9050cm