For the sake of fitment.
Instead of having to group yet another neutral wire into the already large mass of neutrals in my box. If one smart switch is already fitted (G.E.) can I just jump the neutral over from the new installed switch to the 2nd (available) hole on the back of the 1st smart switch?
3 way circuits would effectively be done this way if I’m not mistaken.
Yes, you can and it will work. Ultimately this is your home, you know the reccemended way is to join them all up at the same point and not jump from switch to switch.
Yes, if I can get both switches to fit the shallow metal box than I will run them independently.
Noticing each pole of the switch has dual receptical configuration, I realized this may help others from trying to cram switches into a box and possibly pinch wires and cause a fire.
Not an electrician personally, so I can’t speak with ultimate authority here, but I see no reason what so ever that this would be a problem.
All Neutrals run to the same place. Almost certainly if someone isn’t “Daisy-Chaining” them they they are all pig-tailed together in the back of the box so there isn’t any real world difference that I can think of. Finally nearly every switch I’ve worked with has two holes for each post to put in wires so it seems the manufacturer anticipates that daisy-chaining would happen.
The only negative that I can think of is that if you’re replacing the switch in the middle (ie, the one sitting between the first switch and the final neutral) that the end switch won’t work, but personally, I’d have the main power off anyway so this isn’t any big deal.
Again, I’m not an electrician so maybe there’s some good reason to not do this, but I for the life of me can’t figure out what it is.
Technically yes you can do this and it will work but as far as the code states the answer is maybe.
According to 110-3(b) “listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling” and 110-14(a) states “terminals for more than one conductor shall be so identified”.
So if the instructions or the data sheet explicitly say you can terminate more than 1 conductor under a screw then yes you can do that otherwise per code the answer is no.
It’s probably worth noting that code in different areas will be different though. So it’s possible there are some areas where code states this is expressly forbidden even if the data sheets/instructions say it’s okay.
Likewise there might be some areas where code says this is fine even if the data sheets/instructions don’t say it’s okay to do this.
FWIW, I send an email to my brother who IS and electrician to get his opinion. I’ll report back what he says.
Part of the rationale behind using pig tails instead of daisy chaining between device terminals is that each down stream connection contributes current that flows through the upsteam device’s neutral terminals.
Take the following example: You have three switches (a, b, and c) each rated for 15 amps of continuous current. They are in a junction box and you daisy chain the neutrals with switch “a” nearest to the source and switch “c” furthest. Let’s say each switch “a” is connected to a 1 amp load, switch “b” is connected to a 10 amp load, and switch “c” is connected to a 5 amp load. Since the neutrals are daisy chained the current flowing through each neutral terminal is the sum of the load connected to the switch plus all the down stream loads. This would result in 5 amps flowing through the neutral terminals of switch “c”, 15 amps flowing through the neutral terminals of switch “b”, and 16 amps flowing through the neutral terminals of switch “a”. You are now subjecting the neutral terminals of switch “a” outside of it’s rated ampacity.
If we look at your specific case, will you have this problem? The answer is probably not, but when it comes to developing codes, standards, and best practices we typically use the worst case scenarios.
And this is why I qualified by saying I’m not an electrician!
But the end wires… where the pig tailing happens… still gets the full 16 amps of course (using your example). Are normal wires, by default, rated for higher amps than screw end of a neutral?
In my application there won’t even be 5 amps combined…maybe 3 tops I will know for sure once I get home and do the math on the bulbs in my garage.
The G.E. 12722 is rated for 15 amps continuous so looks like all is within spec there.
The new switch is a G.E. dimmer will have 1 led on it so very minimal issue there.
Good stuff. I learned a little bit. Thanks everyone!
My brother just got back to me and basically said exactly the same thing @Matt_Hartig did above.
Stack too many devices and the amps can jump above the rating for the posts. Probably would never happen in “normal” setups, but could potentially be a problem so should be avoid if at all possible.
Of course the above is strictly for informational purposes. You should consult whatever code applies to your area.
First off, I’m really glad we are getting to have these conversations because electricity is hard! It gets me really excited when folks are taking a genuine interest in how things work, and asking questions is a great way to learn.
In response to your question above, I get to use one of my first mentor’s the favorite responses… It depends. The ampacity of a conductor is related to the size of that conductor. The two most common size conductors you’ll see for general purpose residential circuits is #12 and #14. A #14 conductor is rated for 16 amps and a #12 is rated for 20 amps. So both technically would “work” in my previous example. If we upped the total current to 17 amps then the #14 would not work but the #12 would.
I’m a licensed Wisconsin industrial electrician…I don’t know of any state or municipality that modifies “listed or labeled” it would make the code ever more complicated and convoluted but it is never a bad idea to consult your AHJ
Since these 3 switches should be on the same circuit the OCPD would protect the overloading of the conductors, both hot and neutral.
Well you would probably know better than I, but the ideal of code being more complicated and convoluted doesn’t seem like it would be something that would stop some states or municipalities from enacting it!
Hhmmmmmmm… My House. My code.
I guess if it is an issue you could always use one unbroken neutral jumper. Just strip out about 1" sections of insulation and wrap the stripped areas around each screw. This would technically be a single conductor under each screw…
I usually just pigtail from one wire nut to another that I add when I reach the capacity of one. From an electrical perspective this should be the same, but I’m not an electrician so I can’t say that authoritatively.
You are absolutely correct that the OCPD will protect the branch circuit. That being said, NEC Table 210.21(B)(3) permits 20 amp branch circuits with two or more receptacles are allowed to have receptacles rated for 15 or 20 amps, so the scenario that I mentioned in an earlier post meets code.
I am not an electrician. I came up with the same solution as Drewbert34 to reduce the number of neutrals on the pigtail in a box with 3 “dumb” switches that already had 5 neutrals in the pig tail. The daisy chain would reduce the number of neutrals added to the existing 5 from 3 to 1. A few posts here point out the cumulative current load issue on the wires when daisy chained, however, I did not see it mentioned that the neutral wire of a smart switch does not carry the load switched by the smart switch, it is only used to provide a the small current to run the electronics of the smart switch itself. Therefore the amperage of the load switched by the smart switch has no bearing on the current draw from the neutral coming to switch. I have seen posts that say the these switches use about 1.5W for their electronics/relay, that is basically the magnitude of the load that would cumulate across the 3 wires. Please correct me if I am wrong on this. or am missing something.