Re: [RE-wrenches] 90 degree wire bends
BANG. 500 megajoules running through a wire at the speed of light. The poor little wire is doing the best is can to transmit the power, creating a freight train of spiraling, magnetic fields along the way. A tight bend, creating high inductance, looks like a 8 foot thick concrete wall. BANG. This time as the energy explodes from the wire to find a path of lesser resistance. That about sums it up. I love it when I see "lightning protection" installations with neatly formed wires following every turn and contour tightly. Bang. Larry Crutcher Starlight Solar Power Systems On Nov 16, 2011, at 9:01 PM, Darryl Thayer 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 > To: RE-wrenches > 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
Re: [RE-wrenches] 90 degree wire bends
Was that on the hots or neutral? It's possible that might have been
lightning too. I've heard of lightning using the pump wiring to get to
the very well grounded well water.
Ray
On 11/18/2011 1:47 PM, Nik Ponzio wrote:
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 <mailto: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 mailto:r...@solarray.com>>
*To:* RE-wrenches mailto: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
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Re: [RE-wrenches] 90 degree wire bends
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 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 > *To:* RE-wrenches > *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
Re: [RE-wrenches] 90 degree wire bends
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 To: RE-wrenches 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
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
