Which conduit/trunking to use?

[GaryinAshby]

....behind dot & dab platerboarded wall? My electrician has asked me to pull the cables through & fasten the trunking to the wall so that he can carry on when he gets back from holiday. No problem, but which is best both from a safety and installation point of view (the walls are celcon blocks)?

I seem to recall that galvanised conduit is available, but wouldn't this need earthing? What do you folks use?

 

[welsford46]

I'm no expert but I'm having a build done at the moment...and the electrician is just tacking the wires to the blocks and then plasterboard will be fixed on top - no other protection.

I'm sure I've read elsewhere that this is fine by the regs.

 

[RF Lighting]

It is acceptable to clip direct to the block, but best practice is to install either oval conduit or capping.

 

[industryspark]

didnt the electrician advise you on the type he wanted installed, poor show if not. galvo trunking/conduit is available yes but you also need to size it for the amount of cables running through it.......and yes it needs to be earthed.

is it single cables been pulled through?

the 17th edition regs which come into force at the start of july, allow for cables (twin and earth mainly if we are talking domestic) to be installed without mechanical protection (in safe zones) if they are protected by rcd.

the 16th doesnt require rcd protection in the same circumstance.

 

[GaryinAshby]

Thanks folks. I was told that I could clip straight to the blockwork, but installing conduit would make life easier in the future IF it should be necessary to replace anything.

This is domestic twin & earth. My main concern was actually getting something that will stay fastened to the blockwork. I'll try the "top hat" plastic stuff & use small screws to hold it in place.

The reason I considered the galvanised stuff is that if it were earthed & someone put a drill or nail straight through it at some point in the future it would give an earth to phase fault & trip straight away. Otherwise if a nail were driven through unearthed trunking straight into the live it wouldn't be earthed until someone touched it.