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How to chain 20A receptacles?

7K views 26 replies 8 participants last post by  deko 
#1 ·
I'm adding a 20A breaker to my service panel and and wiring up a chain of outlets in my garage. I understand all receptacles need to be TR and the first receptacle in the chain needs to be GFCI.

As for wiring, my understanding is that it's INCORRECT to connect the chain through the receptacle. Instead, conductors coming into each box need to be pig tailed so the pig tails connect to each receptacle. This means I would have 3 wire nuts, each connecting 3 conductors, in each box in the chain (except the last). Is this correct?

Also, is there any code stipulating how long the pig tails should be? I know the conductors inside the box need to be a minimum of 6". Does it matter how long the pig tails are?
 
#22 ·
Chevyman....if you can't post nice
Don't post
Your post has been removed

You do not tell DIY to remove an outlet while the circuit is live
I've worked at multiple Hospitals & clinics
Every circuit was clearly defined

Your very post about working on a circuit & kicking the breaker off is a clear indication that you don't do it
BEFORE you work on a life-critical hospital circuit loads are removed from that circuit to prevent problems
 
#2 ·
Well on your first recep you need to go in and out of the gfi to feed all the other receps. Remember that you feed line and feed all other receps on the load side. Pigtailing is the best way on the other receps. 6 inches out of the box and the pigtails should not be to long, remember you need to get all the wire and wire nuts back into the box. Also on the grounds you need to use either a green grounding wirenut or a copper crimp sleeve. I like to use the greenies.
 
#3 · (Edited)
Understood on the GFCI recep.

As for the pig tails, I didn't know I needed copper crimp/green wire nuts! That's the first time I've heard that. I assume standard, uninsulated 12 gauge copper will work for the ground pig tail? no need for green insulated conductor I hope...

I'm thinking 4" should be about right on the pig tails.
 
#7 ·
So pig tailing is optional. Fair enough. But what about the copper crimps/green wire nuts? Are those also optional (when pig tailing)?

I've never used copper crimps/green wire nuts--but will get some it that's what my inspector is going to be looking for.
 
#8 ·
You need to use some approved means to connect the ground wires together. You can't just twist them together. This can be a crimp connector, green wirenut, standard wirenut, or a push connector like this: http://www.idealindustries.com/prodDetail.do?prodId=in-sure&div=0&l1=push-in

If the box is metal, it also needs to be connected to the rest of the ground wires with a short length of bare wire and a ground screw.

I am not an electrician, but FWIW I do not pigtail receptacles either if it's just 2 cables (one in, one out).
 
#10 · (Edited)
The reason why you should pigtail especially for the neutrals is for one simple reason. This was the way i was taught and have been doing it for years like this. Lets say you have a multiwire branch circuit and you don't pigtail the neutral and now you remove a receptacle without killing the breaker. What you just did was remove the neutral and now 120 becomes 240. By pigtailing you can remove the recep without taking the neutral out of the circuit. This is why i do this. You can do it whatever way you want to. And the ground will see voltage of there is ever a fault somewhere in the wiring. Also if you don't know how to crimp them correctly you will break them and they will be useless.
 
#12 ·
Lets say you have a multiwire branch circuit and you don't pigtail the neutral and now you remove a receptacle without killing the breaker. What you just did was remove the neutral and now 120 becomes 240. By pigtailing you can remove the recep without taking the neutral out of the circuit. This is why i do this.
Yes, for a multi-wire circuit you are correct, IF the two circuits are terminated on the same device. This is code required, but it has been established that this is not a MWBC.
Also, WHY are you removing devices without shutting off the power??? This is not a good example for a DIY board.






And the ground will see voltage of there is ever a fault somewhere in the wiring.
Uh, yeah. That's the point. I'm not sure what your point is here.
 
#11 ·
I tried using those copper crimps. They're junk. I'll get some Greenies.

The only question left is To Twist Or Not To Twist. With 2 conductors, the wire nut seems to do a pretty decent job. But with 3 12ga conductors, twisting makes sense because... "the wire nut doesn't make the connection, it only holds the connection."
 
#13 ·
I tried using those copper crimps. They're junk. I'll get some Greenies.
I use crimps. Have been forever. You use whatever works for you. Crimping/greenies are NOT required. A regular wire nut is FINE.



The only question left is To Twist Or Not To Twist. With 2 conductors, the wire nut seems to do a pretty decent job. But with 3 12ga conductors, twisting makes sense because... "the wire nut doesn't make the connection, it only holds the connection."
The wire nut CAN "make" the connection. It also then holds it after.
If a wire nut is used properly the conductors will look like they have been pre-twisted. If you cannot get that same look with just a wire nut then you should pre-twist. The conductors should NOT still be even close to straight after the nut is installed.
Anything more than 2-3 #14's I pre-twist.
 
#14 · (Edited)
Pigtailing is recommended to get into the habit of doing just in case you run into a multiwire branch circuit (e.g. 120/240 volt 3 wire cable).

Also pigtailing lets you do up the hot wires, push the wire nut into the box, then do up the neutral wires, push the wire nut into the box and just have to work two wires (and ground) to get the receptacle into the box. Compared with working five wires to get the receptacle into the box if you did not use pigtails.

Wire nuts with a hole in the small end (Greenies) let you leave one of the ground wires extra long instead of having that many itsy bitsy pieces of wire (pigtails) that may be awkward to hold while you twist the wire nut on. If you had a metal box and forgot to leave one of the ground wires long, you could cut one 12 inch pigtail and line up its middle with the other ground wire ends and use a Greenie and have two ends for the receptacle green screw and the box itself respectively.

Do not put two wires through the small end of a Greenie, the wires will be scratched and scored and weakened as you screw the Greenie nut on. If a pigtail terminates at the wire nut, it is much easier to bundle it with the other wires going in the large end as opposed to using the hole in the small end.

Off topic below.

In the case of the MWBC, if one of the incoming hot wires, say, the red wire, is wire nutted directly to the continuing (or daisy chaining) hot wire because it is not being used in this outlet box, the incoming neutral must also be wire nutted directly rather than relying on two receptacle screws. Hence the requirement of pigtailing as it applies to MWBC's.

Note that if you have a MWBC coming into a box and feeding a GFCI receptacle there, the daisy chaining wire from the load side (for additional receptacles protected by the same GFCI) and the daisy chaining wire from the other (red?) side of the MWBC must have separate neutrals; beyond that point it is no longer a MWBC.

Alternatively connect nothing to the load side of the GFCI and daisy chain all three conductors of the MWBC into another 3 wire cable.
 
#17 · (Edited)
You are right I should not have mention removing a recep with the power on. I am an electrician this is why i said this. Also on the topic of to pre twist or to not I always pretwist. I went on a service call and when i removed a wire nut in j box and the wires were not pre twisted the whole splice blew open shutting off other receps and lights in the house. I always pre twist just so i know that when someone else works on the circuit this will never happen to them. I know that when they remove the wirenut the splice will still be intact. Also wirenuts here do not count as box fill and neither do pigtails.
 
#18 ·
I went on a service call and when i removed a wire nut in j box and the wires were not pre twisted the whole splice blew open shutting off other receps and lights in the house.
Why are you working on live circuits? This is not a safe practice even for professional electricians. Do you also find the proper breaker for the circuit by shorting the hot with your screw driver?
 
#20 ·
Ya know what ?? ya remind me one member here did the almost the same bloody thing before and most case if we do have to do the troubleshooting we use the common sense to find it and only take couple seconds to turn off the source and check the connections etc.

Merci,
Marc
 
#21 · (Edited by Moderator)
So you are telling me that when i was working in a hospital on a job a few years ago and we were changing fixtures and working on other devices that we should have turned off the power. Now let me remind you that it is a hospital and if we turned off the wrong breaker we could have killed someone. So you are saying turn off everything even if someone elses life was at stake?
The Hopsital circuits are well marked and there is no way it can screw up something like that but for the rest of the details I rather not comment at all in this fourm { If you want to debate it do it on the electrician forum but not here }

And in this forum majtory of the members here are DIY and we have to steer them in correct safe manner nothing more if we feel it will be out of the line or feel dangerous we will say something quick.

Merci.
Marc
 
#24 ·
Appreciate all the comments. Very helpful.

I have a related question (yes, I'm a newbie):

What kind of wire nut to use when connecting 3 #12 wires, and how much jacket to strip?

According to Ideal's documentation, the RED 76B wire nut will accommodate 1 to 4 #12's (http://www.idealindustries.com/prodDetail.do?prodId=30-076) and the YELLOW 74B will accomodate 1 to 3 #12's (http://www.idealindustries.com/prodDetail.do?prodId=30-074).

As for how much jacket to strip off the conductor, the instructions on the box say 7/16" for #16 and smaller, and 3/8" for everything else (which I assume includes #12).

For 3 #12's, the RED wire nut is more in the middle of the spec so that seems best, but 1/2" seems to be about the right amount of jacket to strip, rather than 3/8", which seems too short.

Does this sound about right? Are inspectors picky about this?

Thanks in advance.
 
#25 ·
For the 3X 4.0mm² { #12 AWG } use the red wirenut that will work just fine with that useage and just strip 12mm [about 7/16"] and just twist it up and you will be done with it and when you get done do a quick wiggle test to make sure it don't come out.

As long it do not show the exposed conductor the inspectors are useally not super picky but for grounded conductor { bare conductor } some may want to use green wirenut and some may want to use the crimp sleeve and others will use standard wirenut all it depending on which inspector ya get.


Merci.
Marc
 
#26 ·
Great! Red wire nut and 7/16" copper wire sounds good.

As for the crimp sleeve/green grounding wire nut--I've decided to stick with a regular wire nut. Why should I bother purchasing and storing another type of connector? A standard wire nut is inexpensive, interchangeable, and a better quality connector.
 
#27 ·
Follow up question on pigtails:

Does the pigtail need to be the same length as the other conductors in the box (which I've been making 7.5") or will 6" (or even 4") be sufficient?

Also, does the grounding pigtail need to have a green jacket? This sounds silly since the grounding conductor is bare copper, but someone mentioned this on some other forum...
 
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