Hi
Wires in a wall socket are too short, so I need to extend them a few inches using a choccy block and more wire. Its a double socket. But I've heard people criticise the use of choc blocks: is this to current regs? Is there a better way? I cant think of one, the wires are well and truly buried. Should we wrap our choccies in insulting tape now?
Thanks, NT
Use crimps, applied with a proper ratchet crimper, not a glorified pair of pliers.
Christian.
In article , Christian McArdle writes
Or solder?
If the wire is stranded choc blocks are fine but crimps are better, if the wire is solid I doubt crimps are suitable so chock blocks may be the way to go.
Put it this way, choc blocks are no worse than the screw terminal connection on the socket itself. Wrapping the choccy in tape can't do any harm but I doubt it's required.
cheers, Pete.
The issue here is that burying chocolate block in plaster is against the regs. Screw terminal connectors shouldn't be inaccessible. The ones in the socket *are* accessible, so that's different from the ones in the wall. All this doesn't mean that a buried choc-block connection won't be fine, only that it's against the regs. If it did develop a fault later, it would be a right pain to find.
Crimps and solder are considered "permanent" connections, so they don't need to be kept accessible. As for stranded wires vs. solid wires, crimps work just fine on solid wires. I've just bought my first ratchet crimping tool and crimps from
HTH, Al
Assuming the block is within the backing box, I'd go ahead. Overlap the wires so both screws bite into both conductors and do them up good and tight. I reckon a 15 amp block is a better fit than a 30 amp one for 2.5mm cable. It's really no different from the connector on the socket.
We failed NIC inspection for a choc block in a back box - standard choc block is thermoplastic and can melt - porcelain might pass
I see people today talking about butt crimping ..I've done this but always use a one size up crimp and loosely twist the wires & crimp them together like you would in a wire nut & tape them together for strain relief.
seems safer
Good point - I read the 'buried' as the chocolate block would be buried. If it's in the wall box then there's no problem as it is still accessible. Still a good idea to make sure you have 30A rated chocolate block though, unless you want it to melt when you plug in an electric heater. I suspect 15A blocks would be fine for most installations, but not that stuff you get for joining speaker wires!
Al
Then just what are thermoplastic ones sold for? FWIW, the plastic insulation on a standard fitting can burn too and melt in a fashion. High temperature insulation is commonly ceramic, but this doesn't seem to be needed on most standard switches and sockets.
FWIW, a soldered joint covered in heatshrink would fail your inspection too. And if the chock block overheated to the point of melting its insulation, so would the adjoining PVC insulation on the cable.
My point as regards the nominal rating of the block is that to join just two wires you need as snug a fit as possible, IMHO. A 30 amp block allows three 2.5 wires to fitted. I don't think the rating of the block has actually that much to do with how much current it can handle in practice. Look at the size and contact area of the connector on the average 20 amp switch - it is closer to a 15 amp choc block than a 30 amp one, and overlapping the conductors as I'd do so both screws connect must effectively give a better connection.
Thanks folks, all is now clear!
BTW, do I have to get separate ones for earth and live, or can I just do them together?
Regards, NT
I'd use separate ones to allow you to dress the cables to the best positions.
Well I've only got one bit of choccy left, and was thinking it'd save me going out to get another strip of them if I just put both into the one connector. Should be OK? I used the other couple of bits for the meter tails, though I couldnt fit all the strands in - but it works fine.
Regards, NT
Best to lever the meter off the wall and drag it to where the tails will reach.
LOL
Well thats where it was before, but its a bit inconvenient having to duck every time you walk in the door, so I thought I'd move it somewhere sensible. It wont affect the vegetables will it? Dont think it will.
Thanks :)
NT
I think it already has.
lol! excellant
Regards, NT
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