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Mastercarpentry
Re: Best way to extend wires?
canuk wrote:

The cable ( and conductors ) can handle the heat they are rated for --- it's the solder that's the issue.

It's not actually the solder so much as the fact that soldered connections can be done improperly causing later failure. Acid-core solder is a wiring no-no, as is not cleaning all traces of rosin flux after soldering with rosin-core. As a Ham Radio nut I do a lot of wire soldering and I can assure you that a properly soldered connection can be made as good as the conductors it connects. I can also assure you that an improperly soldered connection will most certainly fail sooner or later. Since the quality of the soldered connection cannot really be defined by parameter but only assessed with an experienced eye, it is best that it is not allowed in this application where other methods which can be quality-defined and are adequate can be used to equal effect.

As an aside, in DC home power systems such as solar, all non-terminal wiring connections must be soldered because no other method is capable of transferring the current as well on a permanent basis. Compression-type connections will loosen over a very short time here causing all manner of problems including fires from overheating. The heating and cooling cycles of DC wiring is far more than with AC and the voltage loss from resistance of connections is more critical too. In Ham radio work you learn to solder all your connections unless you want them to fail because they will, especially in mobile setups. You also learn how to solder well (with lots of learned advice offered on how to do that) or you will become something of a laughing-stock among your radio buddies- which helps you learn quickly how to solder well more than all the rest does!

Done properly, a soldered wire connection still reigns king in almost every application, it's just that it is hard to discern the good ones from the bad ones and impossible to delineate the parameters of that difference in a code book.

Phil

Re: Best way to extend wires?
Mastercarpentry wrote:

It's not actually the solder so much as the fact that soldered connections can be done improperly causing later failure. Acid-core solder is a wiring no-no, as is not cleaning all traces of rosin flux after soldering with rosin-core. As a Ham Radio nut I do a lot of wire soldering and I can assure you that a properly soldered connection can be made as good as the conductors it connects. I can also assure you that an improperly soldered connection will most certainly fail sooner or later. Since the quality of the soldered connection cannot really be defined by parameter but only assessed with an experienced eye, it is best that it is not allowed in this application where other methods which can be quality-defined and are adequate can be used to equal effect.

As an aside, in DC home power systems such as solar, all non-terminal wiring connections must be soldered because no other method is capable of transferring the current as well on a permanent basis. Compression-type connections will loosen over a very short time here causing all manner of problems including fires from overheating. The heating and cooling cycles of DC wiring is far more than with AC and the voltage loss from resistance of connections is more critical too. In Ham radio work you learn to solder all your connections unless you want them to fail because they will, especially in mobile setups. You also learn how to solder well (with lots of learned advice offered on how to do that) or you will become something of a laughing-stock among your radio buddies- which helps you learn quickly how to solder well more than all the rest does!

Done properly, a soldered wire connection still reigns king in almost every application, it's just that it is hard to discern the good ones from the bad ones and impossible to delineate the parameters of that difference in a code book.

Phil

Very True Phil, a good solder connection is hard to beat. But, very few people can make a good solder connection. Soldering is allowed in the Code but not everywhere.

Per the 2011 NEC:

110.14 Electrical Connections. See related UL
Changed From 2008
•110.14: Revised by adding a second paragraph to require that terminals and connectors used with conductors that have other than standard stranding shall be identified for the specific conductor class(s). A new Table 10 has been added to Chapter 9 to provide information on conductor stranding.
Because of different characteristics of dissimilar metals, devices such as pressure terminal or pressure splicing connectors and soldering lugs shall be identified for the material of the conductor and shall be properly installed and used. Conductors of dissimilar metals shall not be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum, or aluminum and copper-clad aluminum), unless the device is identified for the purpose and conditions of use. Materials such as solder, fluxes, inhibitors, and compounds, where employed, shall be suitable for the use and shall be of a type that will not adversely affect the conductors, installation, or equipment.

(B) Splices. Conductors shall be spliced or joined with splicing devices identified for the use or by brazing, welding, or soldering with a fusible metal or alloy. Soldered splices shall first be spliced or joined so as to be mechanically and electrically secure without solder and then be soldered. All splices and joints and the free ends of conductors shall be covered with an insulation equivalent to that of the conductors or with an insulating device identified for the purpose.
Wire connectors or splicing means installed on conductors for direct burial shall be listed for such use.
Field observations and trade magazine articles indicate that electrical connection failures have been determined to be the cause of many equipment burnouts and fires. Many of these failures are attributable to improper terminations, poor workmanship, the differing characteristics of dissimilar metals, and improper binding screws or splicing devices.

410.121 Solder Prohibited.
No solder shall be used in the construction of a luminaire recessed housing.

250.8 Connection of Grounding and Bonding Equipment.
(B) Methods Not Permitted. Connection devices or fittings that depend solely on solder shall not be used.

I like to use this same analogy on wire nut connections….always twist the wires to be spliced until you have a good mechanical and electrical connection first….then install the wire nut (which I believe is similar to tape). But, manufacturers instructions say something like …insert the wires into the wire nut, turn until you see several twists appear on the insulated portion of the wire.

Good Luck from Columbiana, Alabama
Maurice Turgeon, http://thesemi-retiredelectrician.com

William
Re: Best way to extend wires?

THANKS for posting this guys! This is really good information to see. I have been working with solder for over 40 years so I fortunately know how to do it correctly. I'm half tempted to redo all of my connections now with solder as well as with wire nuts.

QUICK QUESTION: What is the ruling on heat shrink? Can you "seal" the connection with heat shrink after you put on the wire nut? I would think it would be better than using tape....

Re: Best way to extend wires?
MyMilan wrote:

THANKS for posting this guys! This is really good information to see. I have been working with solder for over 40 years so I fortunately know how to do it correctly. I'm half tempted to redo all of my connections now with solder as well as with wire nuts.

QUICK QUESTION: What is the ruling on heat shrink? Can you "seal" the connection with heat shrink after you put on the wire nut? I would think it would be better than using tape....

That's a technique widely used by industrial electricians, they actually tape the skirt of wirenuts, especially in motor junction boxes where there is high vibration.

It also prevents a stray strand from either entering or sticking out of a wirenut.

Good Luck from Columbiana, Alabama
Maurice Turgeon, http://thesemi-retiredelectrician.com

t_manero
Re: Best way to extend wires?

Basic question about connecting an outlet to a wire circuit .. .

In my previous 1973 Calif house, the incoming NM cable was spliced, and pigtail-ed to the outlet and outgoing NM cable. Crimped steel (?) bands were used as connectors.

In Virginia, my current 1964 house has AC (armored) wiring. It's spliced to connect to 1/2 of the outlet terminal side and the outgoing AC is connected to the other half of terminal side. No pigtailing. The boxes (small) are metal and outlets are grounded to the box by an exposed wire (smaller gauge than 14).

Does national code permit either way ?

With the AC wiring, if I wanted to add another outlet (for more plugs for low-current devices instead of a $3 tap), how would I connect the feeder cable to new box ?

Fencepost
Re: Best way to extend wires?

There's another option for extending the wires (where they are in the box but too short to attach to a device): my local Home Despot sells a push-in splice connector that works similar to the "backstab" outlets (solid wire only). You should be able to push one of these onto even a very short stub of wire.

I'm really not impressed with that concept, I'm not convinced that it's really a good connection, despite what UL and the Code say. But it might be an acceptable solution to this problem.

Re: Best way to extend wires?

Fencepost, I is that connector good for #12?

I too am not real fond of the method.

Fencepost
Re: Best way to extend wires?

Here's a link to the product page:

http://www.idealindustries.com/prodDetail.do?prodId=in-sure&div=0&l1=push-in

Looks like they can take up to #10 wire, and they are listed for stranded wire (there is a max number of strands).

William
Re: Best way to extend wires?

What concerns me about connectors like this is how much of a connection is it actually making. At the point where the old wire is touching the new connector, how much surface area is being used? I am on my way up there to see how these are designed. They sound like they would be perfect for my application, but I feel a bit of caution should be exercised before I run and buy them. THANK YOU Fencepost for posting about them! It may make a very hard task very simple. Ideal makes some good stuff so i'm hopeful that these might work. I'm going to go up there now and take a look :)

William
Re: Best way to extend wires?

They cost 2.00 for 10, or for around twice as much you get 100. I bought the bag of 100 in the 3 port style. They go up to #12 solid or stranded (up to 19 strands). They are designed only for copper wire. My #12 wire was solid and it sort of 'clicked' into the connector. I tried to pull it back out but unless you use a twisting motion the wire will not come out. I pushed the shortened wire and the new connector to the back of the box and my problem was solved :D I probably won't get too much use from these since this situation doesn't (thankfully) arise too often, but for the times when I do need something like this they will be a real time saver. THANKS again Fencepost, the shortened wire is now one less thing for me to worry about. :)

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