Wire nuts & pigtails

Another simple questions.
I have no problem twisting 2 wires before putting on a wire nut, but with 3 - 12guage wires, it's pretty difficult.
Is it necessary to twist wires before you put on a wire nut?
Should you tape the wire nut?

Pigtails
Is it necessary or proper when wiring multiple receptacle to use a pigtail for the 3 sets of wires or can you wire both sets of screws on the receptacle?

Thanks

 

First wire nuts: Most wire nut manufacturers do not require pre-twist on the wire before you apply the nut. Be sure you are using a correct nut for the quantity of conductors you are using.

Most receptacle manuf allow for feed through on the other screws, on the other side of the recept. Do not feed through if you use the push in the back type. Pig tails are also good, but makes it tough to push conductors into box if it is not a deep box.

 

You must pigtail the grounding connection, either with a short piece of wire or with a green nut with the hole in the end.

And on a multiwire circuit (shared neutral), you must pigtail the neutral (but you don't need to pigtail the hot).

Tape the wire nut if you want, but a properly applied wire nut is not going to come off. A properly applied wire nut is one in which it would probably break your fingers before you could get it on any tighter.

Twisting or not is one of those religious discussions.

 

I advise leads on all receptacles unless there's only 2 wires at the outlet. Use #14 THHN stranded for the leads.Twist the two solid #12's together and neatly wrap the #14 stranded around the "twist" and then tape around the wire-nut connection so it's thouroughly(?) insulated.Four #12 wires connected on a receptacle results in a very "stiff" connection when securing the receptacle to the box.Also,a loose wire a terminal will open the circuit,a very common problem adressed to the Forum.You don't need #12 for the leads unless you'r using receptacles rated at 20 amps. and the load on the receptacle is 15-20 amps.Good Luck!!

 

I agree with John. Twisting the wire before putting on the wire nut brings up a variety of personal feelings. My father in law who was a licensed electrician from the old school taught me to twist with lineman's pliers and than cut the tip. This not only creates a solid mechanical and electrical connection, it helps to ensure a tight fit for the wire nut.

I have been corrected by others that most wire nut manufacturers do not require twisting, but in my limited experience, I prefer to do it. It creates a good connection and makes me feel better. As for tape, I have been of the school that if you have bare wire exposed at the bottom of the wire nut than you should re-do. Tape can cause an inspector to look at the joint and create suspicion.

Only my .02.

 

Speaking as someone who has made a great deal of money because of service calls where the wires came loose because they were not twisted together, I'd say twisting them good and tight first them applying the wirenut is a very good idea. The manufacturers will say you don't have to but it is advisable. I know of electricians (not good ones) who don't twist the wires on purpose knowing it increases the chances of a service call in six months to a year. Nothing like drumming up your own repeat business.

 

Boy I always seem to be on the wrong side of the fence. I seem to be there again on this post. The NEC says that you must follow the manufacturer's instructions. Read your installation instructions on your wire nuts and I suspect you will find that the manufacturer does not say "RECOMMEND" The almost always say do not twist.

If you twist you create ball of wires that will stretch out the wire nut if an expandable spring style wire nut and if you are using a hard wire nut you will only get a part of the wires into the nut therefore relying on your twisting. Twisting is not allowed to be counted on as a proper connection by the NEC. A pressure connection is required.

Read you manufacturer's instruction concerning the wire nuts that you are using and follow those instructions. If you don't then you are in violation of the NEC minimum safety standards.

If you are install all solid wires then these wires are supposed to be even when installed within the wire nut.

If you are installing stranded and solid mixed then you must be lead the stranded a bit ahead of the solid wires when installing the wire nut.

Just follow your instructions as per the manufacturer.

Good Luck

Wg

 

if you're having difficulty twisting together three 12 gauge wires, it's because your tool is too small (sorry, dude, nothing personal). Get a good 9 and one-quarter inch linesman's pliers (preferably Klein, sold at HD) and you'll have all the leverage you need to twist them easily. Put the wires in your hand with the start of the insulation of all 3 lined up. Bend all three wires at a right angle about 2 inches back. Grab the bare copper and twist clockwise with the pliers until you have a couple twists in the bare copper and also in the insulated part of the wires. Snip the copper back to about 3/8 of an inch. Twist a red wirenut until your hand hurts. if a magnitude 8 earthquake levels your home, you will find this connection still solid in the rubble.

 

Thanks for all the replies.
Before you twist the 3-12's, how far back do you strip the wires? 1"?

 

WG,
I've never seen any instructions on wirenut boxes or listings that say "do not twist". All of the ones that I have looked at say "pre-twisting not required". I, too, prefer that solid wires be pretwisted. You really don't gain anything, but I think that it is a little easier. If you take off a wirenut from a connection that was pretwisted and one that was not pretwisted you should see no difference. When you install a wirenut the way it should be the wires will always end up twisted.
Don(resqcapt19)

 

PATTBAA,
Using a #14 pigtail to supply a duplex receptacle on a 20 amp overcurrent protective device is a violation of 210-19(b).
Don(resqcapt19)

 

resqcapt; please refer to Table 210.24 and Table 210.12(b) (3)

 

PATTBAA,
Table 210.12(b)(3) only applies to the receptacles and not to the conductors that supply them. 210.24 even refers you to 210.19 for specific branch circuit requirements. There is no provision in the NEC that permits you to one end of a #14 conductor to a circuit with a 20 amp overcurrent protective device and connect the other end of the #14 to a switch or a duplex receptacle. Some taps are permited by 210.19(A)(4), but Table 210.24 does not give blanket permission to use a #14 tap on a 20 amp branch circuit to feed a duplex receptacle. The use of a #14 to feed the duplex recptacle is a violation and around here you would get red-taged every time.

210.19 Conductors — Minimum Ampacity and Size.
(A) Branch Circuits Not More Than 600 Volts.
(2) Multioutlet Branch Circuits. Conductors of branch circuits supplying more than one receptacle for cord-and-plug-connected portable loads shall have an ampacity of not less than the rating of the branch circuit.

The section I cited in my last post was from the '99 NEC but says the same thing.
Don(resqcapt19)

 

resqcapt; I stand corrected. The pertinate article is 210.19 (A) (4) Other Loads which reads "X1-tap conductors shall have an ampacity for the load served. In addition--------only where these tap conductors supply any of the following loads: (a), (b),(c),individual outlets OTHER than receptacle outlets, (d),(e). X2 permits fixture wires smaller than #14------Thanks for the reply.