Post by thread:[OT] Voltage drops (was Widlar Optimisation...)

Howard Winter <spam_OUTHDRWTakeThisOuTH2Org.demon.co.uk> wrote: {Quote hidden}> On Mon, 8 Aug 2005 13:39:06 GMT, .....shb7KILLspam@spam@netzero.net wrote: > > Howard Winter <HDRWKILLspamH2Org.demon.co.uk> wrote: > > > Did you know they habitually join wires by twist-and-cap? > > > I thought it was a bodge until I saw the stuff they sell > > > at Home Depot - it seems to be the accepted practice! :-# > > > > What is the accepted practice in the UK? > > Screw terminals, preferably in the accessories themselves (switches, > sockets, ceiling roses) which are generally designed to take at least > three of the appropriate sized wire, or if that's not possible in > connecting blocks ("chocolate blocks") or junction boxes like this: > http://www.tlc-direct.co.uk/Images/Products/size_3/BG603.JPG but these > have to be "accessible", and there's much discussion of the > interpretation of that! If a join isn't going to be accessible > (eg. extending a cable to move a socket, and then plastering over the > join) then it has to be crimped, which is regarded as a permanent join so > doesn't need to be inspected once it's been made and tested. > > I believe twisted joins were disallowed in the regulations some time in > the 1970s. We're actually a step ahead of you, then, because we (NEC) don't allow inaccessible joins at all. Wirenuts are not just a "cap" over a twisted join. The metal thread forms a high-quality gastight connection with the wires. When properly applied, they are at least as good as crimps and screw terminals, if not better. In fact, if you've got more than one wire to attach to the same terminal of an accessory, it's actually preferred if you use a wirenut to join the wires, including a short pigtail that goes to the accessory. Seriously, if you're going to do wiring over here, you'd be well-advised to become familiar with the National Electric Code, upon which nearly all state and local codes are based, if you don't want to create unnecessary grief for your GF down the road. It's published by the National Fire Protection Association (http://www.nfpa.org/). -- Dave Tweed