Oh…one quick point…you know how wirenut manufactures list the instructions saying do not pre-twist the wires before they are placed in a wirenut…seems to me that would come apart sooner than a good twisted and soldered joint …just a point of view…I really do like soldering joints…it was fun and (1) torch and large roll of solder went a long way…
Ok… I’ll try…
First off I think we’ve established the following:
- The connection is disallowed by code and most likely violates the listing of the terminal on the breaker. So it’s wrong on paper if nothing else.
- The branch circuit itself might be OK if the load isn’t abnormally high. So the connection of what used to be two circuits to a single overcurrent protection device is not necessarily an issue.
However, If I hear you right, what you’re more asking is “why” it’s wrong from the physics perspective…
First off I’ll go off the record to say that it might never fail depending on how the soldering is done, and what the shape of the soldered conductors is relative to how they fit under the screw, and of course the load flowing across the termination. Then again, MANY improper installations go on a long time (or forever) without failing… and obviously that doesn’t make them right as Paul has said.
However I see two potential problems:
-
The shape of this joint and how it makes contact under the terminal. Depending on how the joint was made, it could be irregular or made in such a way that one conductor makes better contact than the other, and thus forces electricity to flow (partially perhaps) over a narrow layer of solder, or in some other uneven way.
-
I don’t think it will take much pressure from a screw terminal joint to deform a soldered connection to the point of being less reliable than it would otherwise be if it was just taped and left alone.
Perhaps the bottom line is that the manufacturer probably never tested such a configuration under standard tests. It is likely unknown exactly how it will perform or any factors at play on the connection.
I’m sure the others will chime in on other ideas as to why this could be an unsafe/unsuitable connection.
hmmm…I think we are getting off track here…If the question is can you solder (2) wires together and CRAM them in a listed OCPD…no that is not something I would suggest you do…and WHY would you want to do it…
Soldering (2) wires together with a third wire to use as a pigtail to the OCPD is fine…if your local AHJ lets you solder…as stated some dont…their personal feelings come into play and Art 80 gives alot of lee-way to the local AHJ.
With that said…really a MOOT point…it is pointless to solder two wires together and try to place them under a OCPD screw…what if the solder is weak…or a poor job…it could spring loose…of the compression of the required torque could be wrongly measured onto the solder rather than the conductor to which is is supposed to…
So basically…lets kill the issue…if the question is can you solder two wires together and put them under a OCPD set-screw…NO…the OCPD is not listed for this type of connection method…
Also the torque would not be corrrect…as the connection point would not be in contract with the conductor…it could be in contact with a crappy solder joint…so I HOPE that is not what the question was…
If you are just asking…Can you splice in a panel or how to do a splice fix of a double tapped branch circuit…then please re-read my original post.
Hope this helps…
Really? Oooops! I’ve allways twisted them first. I guess I never actually read the instructions for wirenuts
That is assuming that a two wires soldered together are still concidered to be two wires and not one. Mechanically and electrically It would to me that it perform more closely to a single wire than two; but I don’t make the rules.
Precisely!
:-k I could see that point.
Bingo!!
Yep…I always twist them as well…What the heck do those manufacturers know anyway…
The wirenut instructions say “it is not necessary to twist” not that it is prohibited. As for the idea that you can’t feed 2 circuits from one OCPD, that is not an issue. I can easily overload a single duplex receptacle with 2 hair dryers. My wife and daughter <2 people for you folks in Kentucky ;-)> have field tested that. 240.4(D) takes care of it.
It is only how the connection is made to the terminal. Two wires twisted in a knot is still 2 wires and I can’t think of anywhere that is legal under one screw. There are breakers that can take two wires, properly installed on opposite sides of the clamping plate.
Greg,
I was not saying that manufacture says you HAVE to twist the connectors in a wirenut…maybe i did say that…I know not sure…but the instructions that come with the nice little wirenut boxes instruct the consumer to not pre-twist the connections…that is all I was really saying so that i could explain the concept and my opinion on soldering joints…I like soldering actually…but I digress…
I dont think they were asking about twisting wires into a knot or joint and then place under the OCPD screw…unless I missed something…lol…which is possible…lol…I think that is where the topic started to stray a bit…lol…but we got it back on track…lol
Greg…and I though MY wife was the only one testing the proper working method of OCPD’s…lol…and we are in Virginia…lol
I agree properly done soldering is probably the best joint. I just doubt many current electricians have that skill … or the right tools.
By “knot” I was just referring to the twisted/soldered cludge of wires that was installed in the OCPD … if I got the scenario right.
If these were wrapped in a good old 1940 tap splice and then soldered, with a pigtail out for a single wire connection to the OCPD I don’t have a problem at all.
Maybe one of us could make up some good splices and solder them with pics so folks could see what a western union (or tap) splice looks like.
greg…Sounds Great…Since we ran into an issue where the local AHJ’s started frowning on Soldered Joints I will have to see where I put my solder roll…If you have it handy go ahead and post it…
I never understood the issue of 110.14(B) to be honest with you…anyone who makes the old style unions or joints with solder and pre-twisting the wire connections prior to soldering makes a mechanically and electrically secure connection without the solder…more so than a wirenut per say…so to hear a local AHJ give us hassle about it always blew my mind…
Guess we BOTH are just old school…lol
Knob and tube joints used to be soldered.
As to wire nuts I like the nuts that have the brass sleeve, with set screw and plastic cap.
I have yet to see any electrician use a torque screw driver on a terminal screw.
me too 
me neither 
WHAT…I have my torque screw driver always handy on every job…lol…
Greg…Now I know you have YOUR torque screw driver at your side as well…Right…
nice images Greg- I have to say most of the soldering splices I have done in the past 15 years is simply twisting a normal joint of 2-3 wires together like it is going into a wirenut…yet soldering it and taping it.
But those joinst above…Take me BACK…
Got torque?
Torque Guages.
Gauges? We don’t need no stinking gauges! (said with mexican accent)
Just tighten until you hear that distinctive “crack” sound. :shock: Then you know you’ve tightened enough. 
How does the ratchet torque wrench fit onto those terminal screws? 
yuk, yuk…
lol…anything can fit if you have hammer handy Raymond…
Here is what ya need to knock yourself out checking the torque on those pesky terminal screws … and for a mere $150 you too can have one of these screwdrivers … 
(I can see Gerry B. our resident tool guy flipping through the Klein catalog now so he can equip himself to exceed the HI SOP again … 
… duck)
