Electric circuits in old houses--the Random Approach

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Oh, really? Care to provide an explanation?
--
Regards,
Doug Miller (alphageek at milmac dot com)
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On Mon, 30 Oct 2006 13:42:07 GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:

I have six houses in a neighborhood development built in 1942 by the United States of America (Federal Government). It was designed to house workers who had come to town to work for the various gun manufacturers in my area.
All of these houses had what I'd call "Octopus" wiring using BX and soldered connections. Octopus since the wiring runs up an outside wall from the breaker box to the attic. The wiring then runs across the attic, dropping down all four walls of the house to each room.
In EVERY one of these houses, the soldered pigtail joints have failed. In most cases it is the neutral connection that has failed. WHY mainly the neutral? I dunno....
Most of the neutral pigtails are in the overhead light boxes that were used for the dual purpose of being a junction box for a second circuit aside from feeding the light fixture. Wartime material shortages perhaps?
In any event, I've cut and spliced all the neutral connections with wire nuts to eliminate the problems. I would get tired of having one circuit rise to 200 volts while another dropped to 40 volts depending on the load.
I've even done it for neighboring houses after an electrician they hired couldn't figure out that the junctions were all in the overhead light boxes in each room.
My point is that soldered joints can corrode, oxidize, crystalize or whatever and indeed go bad.
Doug
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I would agree with the statement that K&T support is regional. I live in an old Mill Town in Massachusetts, my house was the First to get electrical service in the district and it is actually on the historical societies "Walk through Time." Granted most of it has been upgraded from when the first little light buzzed on however the house still has K&T along with other multifamily homes I own in the area. I have never had any issues with the insurance of these properties. The one thing I however do try to mitigate when I come across it is old K&T that has been spliced over the years when someone performed a mild to massive renovation and just tapped into an existing run. I believe K&T to be inherently "safe" as long as people don't muck with it.
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Doug wrote:

Doug:
200 volts...hmm...are both these 'circuits' in the same overhead box? It sounds like these were actually one multiwire circuit...and this is just what would happen with a bad neutral.
I wonder why the neutrals would fail first, though, all other things being equal. If somebody down the road had mistakenly connected both hot conductors to the same service bus, I could definitely understand it (the neutral would then be overloaded, being trying to simultaneously carry current from both circuits) but then the 200v / 40v issue would not be possible...an open neutral would simply cut out both circuits. Furthermore, with a multiwire circuit the neutral only has to carry the current that's not balanced by the 2 hot conductors, so it should be loaded more lightly.
Wire nuts or no wire nuts, I think I'd be worried about what's putting so much load on that neutral.
Did this 200v/40v issue and the neutral-overload issue happen in the same boxes?
Cordially yours: G P
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On 31 Oct 2006 13:01:01 -0800, snipped-for-privacy@gannon.edu wrote:

Thanks for the comments. It could have been one multi-wire circuit. I didn't trace out all of the connections and its been a few years - about 4 years since I respliced the last neutral.
However, the problems happened repeatedly in 4 different houses - three homes were owned by me and one was a neighbor's.
In most cases, when the neutral opened, one or more outlets simply went dead.
In one case however, when a neutral opened, the return current tried flowing thru the BX ground, got to a light switch box where the clamp screws may have been loose, made the switch cover plate screws hot and scorched the wall. Luckily there was no greater fire. That's went I went into high speed mode replacing the soldered neutral pigtails in as many houses as possible.
I went room by room in each house, checked every visible switchbox, outlet box or junction box. ALL of the junctions were made in the boxes for the overhead lghts.
In the time since, there has never seemed to be a neutral overload issue.
Doug
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Doug wrote:

Doug:
Yikes. So apparently some connection came loose , the neutral touched the box, and BX showed one of its endearing properties? Of course K&T and old Romex aren't grounded, so the box would just have been live, and maybe electrocuted somebody, instead of possibly going unnoticed long enough to burn the house down. So the choice that these three old wiring methods seems to give in this situation is between diurnal electro- cution and nocturnal incineration. There's a Hobson's choice for the insurance actuaries. :(
It still puzzles me that only the neutrals failed. Very curious. Some kind of de facto or de stulte multiwire circuit is all I can think of, unless the original installer just didn't think neutrals mattered. Ideas anyone?
Cordially yours: G P
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snipped-for-privacy@aol.com wrote:

Cite statistics.

I agree with Doug - cite information. I have seen 2 solder joints fail (in power wiring). Both were "cold joints" when made.
--bud--
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But, overall, aren't you more comfortable w/ solder than wire nuts? -- Mr. P.V.'d (formerly Droll Troll), Yonkers, NY Stop Corruption in Congress & Send the Ultimate Message: Absolutely Vote, for *Anyone BUT* a Democrat or a Republican Ending Corruption in Congress is the Single Best Way to Materially Improve Your Life entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie, all d'numbuhs
wrote:

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Proctologically Violated wrote:

No. Most wire nut failures I have seen are from a wire slipping back when the wire nut was put on (so the wire was not clamped by the wire nut). My experience has been wire nuts are reliable. And solder joints are a PITA for troubleshooting and circuit extensions.
If you are talking about making solder joints now, most people don't have the skill (even if you solder electronics), and soldering and taping take too long. I have read that in the 'good old days' of soldering joints in boxes, the wires were twisted, fluxed, and pointed down, and then were soldered by bringing around a solder pot to dip the joint. Probably a lot faster and more reliable than using an iron.
-- bud--
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wrote:

I still wanna know what those wire-nuts with the threaded brass cannister and set-screw inside are called, and where I can get more.
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Goedjn wrote:

Try looking for Ideal 30-210 30-211 30-222 The title was set screw connectors.
My favorites are wire nuts with a "live spring" that deforms and expands over the wires.
-- bud--
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Bud-- wrote:

I have seen a great many solder joints (though not on power lines) fail when the solder "crystallized" due to thermal cycling, something that old and undersized (by today's standards) can easily see from big loads like heaters.
Pete C.
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Proctologically Violated wrote: ...

...
I haven't read the entire list of replies as all (at least so far as I went) seemed to fixate on (perceived) deficiencies of K&T and subsequent dire warnings... :(
In answer to the question, this almost identical post came up only a week or so ago. The answer is, there probably was quite a bit of thought actually given to which outlets/lights to put on a given circuit and you can (and should) be thankful for the foresight. The point is that if any particular circuit trips, you will still have lights/outlets at least nearby if not actually in the same room. Consider, for example, the fuse box is in the basement and it's midnight and that is the circuit that is blown--not particularly convenient to now try to find your way there to replace the blown fuse is it? OTOH, if there's a light in the basement on another fuse/circuit...
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An office building I worked on had separate lighting circuits and the circuits would "skip" adjoining rooms. So lighting circuit "A" would go to rooms 1, 3, 5. Lighting circuit "B" would go to rooms 2, 4, 6. Etc.
Then outlets would be on separate circuits in the same manner.
So if a room outlet had a circuit trip, there would still be lighting and power on the outlets in the room next door. Or if a lighting circuit tripped, there would be lighting in the room next door and the outlets in the room would still have power. (If someone needed to work on the lighting in a room, they could still see from the light provided by the room next door or hallway.)
Hospitals have separate circuits in the *same* room. Some outlets are on backup power in case of a power outage.
So maybe someone gave some thought to wiring things in this manner so if one circuit tripped, an outlet nearby would still work or the lighting would still work. ???
"Proctologically Violated" wrote in message

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Solder can detoriate over time, it grows crystals and changes.
insurance companies have stats to prove that K&T has more fires........
What other device do YOU have thats near 100 years old?:(
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snipped-for-privacy@aol.com wrote:

3rd request - provide evidence. The 2 failures I have seen were bad when made.

Second request - provide the stats. In a previous link was - information from an investigation done for Illinios that did not find a problem with K&T - information from a Maine challenge to an insurance company where the insurance company lost because it did not provide statistics
-- bud--
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Bud-- wrote:

my best friend almost lost his home to a K&T bad solder joint it was original to the home, had never been altered. fortunately it was in the basement cieling and not buried in a wall somewhere.
my friend happens to be a electrcal engineer, with a ton of letters after his name from Carnegie Mellon university in pittsburgh. he went down the basement smelled the tell tale odor, found the joint.
it got resoldered......
he told me solder can detoriate under time from thermal cycling........
as far as the maine challenge for practical purposes who wants to go head to head with a insurance company?
if your trying to sell a home, good luck K&T is the kiss of death, right along with flooded basements:(
stuff like you cantinsuklate a wall with K&T in it.....
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..

Unless it's already a defective join, why should there be thermal cycling? How much heat does a 14GA copper twisted wire pair at 15A generate, anyway?
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Bud-- wrote:

Not home electrical wiring, but I spent a year or so doing stereo repair at a friend's shop. A very very common problem was failed solder connections in the stereo receivers due to the significant thermal cycling they saw. The solder would crystallize and develop a stress fracture ring around the component pin and become intermittent. This was particularly prevalent on units where the wave soldering deposited a fairly small amount of solder, resoldering manually with a more generous amount of fresh solder would fix the connections and make them more tolerant of the thermal cycling.
In an old home situation both the significantly greater age of the solder, combined with the thermal stress from applying modern heavy loads like space heaters, hair dryers, toaster ovens, microwaves and air conditioners to old 14ga wires on circuits that have been over fused because they kept blowing the proper 15A fuses has a high probability of causing those solder connections to fail if other parts of the circuit don't fail first.

I have no doubt that K&T wiring would have statistically more fires associated with it, but related to over fusing in the old edison base fuse panels and more modern "hack" add ons to the K&T wiring. A K&T installation that has not been modified and is fused with the proper fuses is in all probability just as safe as any modern house wiring. The K&T is just far more likely to have been hacked over the years.
Pete C.
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Pete C. wrote:

PC:
In this case, the solder *is* the conductor. This has never been proper practice for home wiring, where you start with a sound mechanical connection, and use the solder to seal and secure it. There should be no stress on the solder to cause fatigue, and if the joint is grossly overloaded to the point that the wires become hot enough to melt lead, the lead could melt completely without letting the joint open. You'd have other problems by this time, of course.
One problem is that the inaccessible splices may not be properly done, and another is that somebody might have hacked something on without regard to proper workmanship. But fatigue of the solder is not an issue with a proper Western Union, tap, or pigtail soldered splice. (What is often called 'crystallization' in metal due to cyclic loading is actually evidence of fatigue).
Cordially yours: G P
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