I had an off-grid customer report that their huge well pump surge caused an insulation melt-down at a tight bend in the wire.
On Wed, Nov 16, 2011 at 11:01 PM, Darryl Thayer <daryl_so...@yahoo.com>wrote: > I have seen the lightening damage at tight bends, but in my electrical > career of 60+ years I have not seen any other > problems. > Darryl > > *From:* Ray Walters <r...@solarray.com> > *To:* RE-wrenches <re-wrenches@lists.re-wrenches.org> > *Sent:* Wednesday, November 16, 2011 12:11 PM > *Subject:* Re: [RE-wrenches] 90 degree wire bends > > It seems that if the strands were stretched and therefore thinned, that > that would increase resistance, some. I think more importantly, the > insulation bunchs up and cracks, and is definitely compromised. Also with > strain hardening of copper, I'm sure some strands could break internally > with a tight enough bend. I've heard at least for bare ground wires that > lightning will jump off to the case at tight bends, but I've never actually > seen that. > Aside from all that, is there actually an increased impedance from a tight > bend (like in plumbing)? I don't know. > I've had to stop more than one journeyman from violating 300.34. I just > tell them the bends should look like the long sweeps in conduit relative to > the diameter of the wire: also purdy. > > Aloha, > > Ray > > On 11/16/2011 10:35 AM, Marco Mangelsdorf wrote: > > Some electricians have great fun in making 90 degree wire bends to try > and make their enclosure wiring look so purdy. > > Given the importance of maintaining wiring radiuses, this can’t be a good > idea, can it? Is the issue greater resistance when the wire is bent at a > straight 90 degrees (or more)? > > Thanks, > marco > > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & > settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette:www.re-wrenches.org/etiquette.htm > > Check out participant bios:www.members.re-wrenches.org > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > >
_______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
