On 10/9/2011 9:11 AM, andy pugh wrote: > On 9 October 2011 01:44, gene heskett<ghesk...@wdtv.com> wrote: > > >>> http://www.tlc-direct.co.uk/Images/Products/size_3/AAJB5.JPG >>> >> Yikes! Perhaps marginally useful with stranded wire, but cold flow after 6 >> mo to a year would have me laying awake nights unless your locale has flat >> outlawed alu wire. Even with copper, I would want to re-tighten them at 3 >> to 5 year intervals because cold flow will eventually reduce the pressure >> > Aluminium wire is not allowed, no. Not for a very long time, and I > have never seen any. (lead-sheathed, cotton-insulated yes, but no > aluminium) > Junction boxes must always be accessible to allow for re-tightening. > Whether anyone ever does is a different question. > > Are you saying that Wire Nuts stay tight indefinitely? And that they > have enough contact pressure to maintain gas tightness? > > How do you make the connections to lamp holders, plug sockets and > switches? Are those not screw-clamp? > >
Aluminum wire works fine if properly prepared and anticorrosives is used to prevent it from oxidizing in the terminal. Aluminum cable is routinely used as the power feeds to houses in the US. I have an underground service to my house and it is very heavy Alum cable. I have another heavy alum cable that feeds my shop and I have never had any issues with them in 16 years. The reason they banned it in the US for in house wiring is that the installers would routinely ignore the installation instructions and some fires resulted. I once rented a house back in the early 80's that had all alum wiring throughout the house and it had constant electrical issues. I had to remove several outlets in the house, and re-terminate the wires to new receptacles since they were arcing due to poor wire preparation. The house was all electric and at one point the electric furnace stopped working - the wires at the furnace were arcing in the terminals. Some sand paper and anticorrosive and a few minutes later the heat was back on. I could have called the owner but the women was clueless, and I would have likely had to wait for days until the heat was restored. Wire nuts... well that depends on what kind of wire nuts you use. There are some really poor quality ones available that somehow got UL approval. The major brands ones do maintain a tight hold on the wires, but some are better than others. 3M had some wire nuts that were very popular years ago commonly called Scotchloks. They were outstanding wire nuts. If you put them on too tight, they were not removeable. I worked at a plant that had miles on conveyor in it and everything was wired using 3M Scotchloks. We were constantly ripping out and reinstalling conveyors and the wires were run in wire ducts beneath the conveyors and subject to vibration. We had very few problems with bad wiring connections due to the wire nuts. Apparently they still make them but I haven't seen them on a store shelf for years. They were significantly more expensive than other wire nuts, but worth it. http://solutions.3m.com/wps/portal/3M/en_US/Marine/Home/Products/Catalog/?PC_7_RJH9U5230GE3E02LECIE20S4K7_nid=GSMRH4FQS1beVB2NDGZBTHgl If used properly, Scotchloks can be as reliable as crimp on connectors. >>How do you make the connections to lamp holders, plug sockets and switches? Are those not screw-clamp? A lot of those are simply screw terminals. Wrap the wire around the screw and tighten. Some have actual screw clamps. Some have spring clamps. Dave ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2dcopy2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
