[Squidstro]

I have a 3 gang electrical box in my home with 3 toggle switches. The home was built in 1980 and it should've been wired by licensed electricians. I'm the only owner of this house since it was built and this switch box was never modified. This is how crowded the box currently is with those 3 switches:

I want to add one more 14/2. I want to convert that switched outlet to full time power. And then with the new 14/2, I want to repurpose that single pole switch to control new LED wafer lights in the ceiling of a living room. But those splices are already seemingly maxed out. Adding 3 more conductors will make them even worse.

I listed the inside dimensions of that 3 gang box. I glanced at a NEC table for electrical box fill maximums but I got confused real fast. My questions are:
1) Does anyone know the NEC code on how many wires that box is allowed to have and can I even add another 14/2 run?
2) Regardless - what are the proper techniques for splicing such a large amount of 14 gauge wires? Currently there are 10 ground wires spliced together if you include the 3 pigtails going to the switches. There are at least 5 neutrals twisted together in a big red wire nut. There are at least 5 hots twisted together in a big red wire nut. I haven't been able to open everything up and diagram what's going on - but the point is this is a lot of conductors that need splicing and 3 more would be added.

I noticed from the limited vision I had in the box that all those grounds were using crimp connectors and it seemed to be branched into 2 different crimps with a pigtail. But the hots and neutrals were both in big red wire nuts and they seem maxed out. So please let me know your opinions on how to splice such large amounts of wire together (even if I can't add another 14/2 run to that box. I'd just like to know how electricians splice that many wires together).

Even though my 3 gang box is from 1980, I see they still have new work 3 gang boxes today with 12 wire entrance knockouts. I understand that is for convenience of where you want your wires to land - not necessarily that you are allowed to send 12 runs into a 3 gang box - so that goes back to my question #1

Thanks for your time!

 

[joed]

I think this is correct for NEC.
#14 wire counts as 2 cubic inch (ci)
Box is 56.7 ci.
3 sw = 6 ci
all grounds = 2 ci
leaves you with 48.7ci
#14 wire counts for 2 ci. That means you should be safe with up to 24 #14 wires. You have 16 now. That leaves room for 8 more.

 

[afjes2015]

Also, take a look at this box fill calculator and explanations. It will assist you with this and other projects.

 

[MTVhike]

With that many connections, my guess your primary problem is with the ground connections. Even though you're not exceeding the fill calculation, it's still crowded in there. I would consider getting a ground bar something like this: SQUARE D PK12GTA : LOAD CENTER EQUIPMENT GROUND BAR ASSEMBLY | Gordon Electric Supply, Inc. and put all the grounds into that. Is your current box metal or plastic? You can get similar things at your local BB store, and shorter ones too.

 

[C'est Moi]

What does it state in the back of the box for cu.in. Right now you have 46 cu. in . If you add another 14/2 then add 4 so you will have 50 cu.in-- I won't get into the 2020 calculation----

If there are pigtails on the grounds to the switch you can just disconnect one pigtail and make another splice to connect it to the grounds. It does not have to go under the wirenuts to connect to all of the equipment grounding conductor's.

So first off what is the cu. in of the box

 

[afjes2015]

I would consider getting a ground bar something like this: SQUARE D PK12GTA : LOAD CENTER EQUIPMENT GROUND BAR ASSEMBLY | Gordon Electric Supply, Inc.

The link you provided is for a ground bar that fits into the breaker panel not the box. Ground bars like that are specific to the make model of the breaker panel for fittting.

It seems by Joed's calculations that the 14/2 that Squidstro wants to add would not exceed box fill code.

Squidstro you can eleminate some of the ground wires by using one long ground wire and jumping it from the wire nut to each of the screws on the switches; loop the ground wire around each ground screw securely then go to the next switch ground screw with the same ground wire and do the same. This way you don't have a separate ground wire coming from a wire nut going to each of the switches.

Just be sure you get a large enough wire nut for any bundles of wires you are nutting. HD and Lowes (or big box in your area) sells large wire nuts in small packs of 5 or so (the packages indicate how many of what gauge wire they can handle by code). Just make sure the bare wires (the end you strip) at the ends are long enough and twisting of the wires is good enough when you place them in the nuts. Some say you don't have to pre-twist the wires prior to placing them in nuts but I do it. I guess it is preference.

 

[MTVhike]

The link you provided is for a ground bar that fits into the breaker panel not the box. Ground bars like that are specific to the make model of the breaker panel for fittting.

It seems by Joed's calculations that the 14/2 that Squidstro wants to add would not exceed box fill code.

Squidstro you can eleminate some of the ground wires by using one long ground wire and jumping it from the wire nut to each of the screws on the switches; loop the ground wire around each ground screw securely then go to the next switch ground screw with the same ground wire and do the same. This way you don't have a separate ground wire coming from a wire nut going to each of the switches.

Just be sure you get a large enough wire nut for any bundles of wires you are nutting. HD and Lowes (or big box in your area) sells large wire nuts in small packs of 5 or so (the packages indicate how many of what gauge wire they can handle by code). Just make sure the bare wires (the end you strip) at the ends are long enough and twisting of the wires is good enough when you place them in the nuts. Some say you don't have to pre-twist the wires prior to placing them in nuts but I do it. I guess it is preference.

Yes, it's made for a breaker box but can be used in a junction box, preferably attached to that box.

 

[Squidstro]

View attachment 728725

I took a pic of the inside of that switch box:

There are 6 neutrals in that one wire nut. There are 6 hots in that other wire nut. The white wire is a hot for one of the opposite 3-way switches that one of the 3-way switches in this box works with. It's configured as a switch loop at the opposite 3-way switch so that white wire needs a black label since it's used as a hot. The red wire coming out of the hot wire nut is just a pigtail for the single pole switch's line side.

So the 3 switches in this box are (single pole on the left side of the box controlling a single duplex receptacle) ; (a 3-way switch in the middle controlling a chandelier) ; (a 3-way switch on the right controlling a foyer ceiling light)

There actually are two ground pigtails for the two 3-way switches. But the single pole switch doesn't have a ground wire connected to it. So from my original diagram, there are 7 ground wires plus 2 pigtails all bonded together. You can see the ground twisting behind the hot wire nut. There are at least 2 crimps. I think they twisted together possibly 6 of those ground wires and crimped them along with a pigtail with another crimp for that 7th wire plus the 2 pigtails going to the outlets.

So with my plan to run a new 14/2 into that box from new retrofit wafer lights in my living room ceiling - here is what I'm thinking for that box:

1. Take the single pole switch's line and load hot wires and twist them in a new smaller nut together with a pigtail hot for my new single pole switch circuit that will control the new retrofit wafer lights. This will make that duplex outlet have full-time power which I'm ok with. This will also prevent me from having to undo the 6-wire hot wire nut since it's maxed out and won't be easy to work with.
2. I won't be as lucky with the neutral nut for the new 14/2 run. I'll have to undo that nut, remove and untwist 1 of those 6 conductors, add a new white pigtail wire into that 5 twist of wires to bring it back up to 6 wires and put a new 452 red wire nut on them. Then with the pigtail neutral, twist it together with my new 14/2 neutral wire in a new smaller wire nut.
3. Figure out how to tap the new 14/2 ground wire into the hodgepodge of 9 ground wires, plus a new ground pigtail for my single pole switch to control the wafer lights. I heard your suggestions to potentially use the same ground pigtail in more than 1 switch if it's long enough. But unfortunately the two existing pigtails are not. I still have to figure out how to bond the new 14/2 ground wire, so I might as well figure out how to bond a new pigtail as well.

2) Regardless - what are the proper techniques for splicing such a large amount of 14 gauge wires? Currently there are 10 ground wires spliced together if you include the 3 pigtails going to the switches. There are at least 5 neutrals twisted together in a big red wire nut. There are at least 5 hots twisted together in a big red wire nut. I haven't been able to open everything up and diagram what's going on - but the point is this is a lot of conductors that need splicing and 3 more would be added.

As for this question - it looks like the electrician who did this original work maxed out the 452 wire nut with six 14 awg solid conductors. I see online that seems to be the critical mass maximum of that size wire nut when it comes to 14 awg solid conductor wire. Even though there are bigger wire nuts than the 452 for bigger gauge wire splicing, I don't think you can add 7+ 14 awg wires to any of those big wire nuts. So I'm wondering what licensed electricians do for over 6 conductor splicing in new work construction. A lot of jurisdictions are using 12 awg wire for most new work wiring. That makes this dilemma even worse. These 3 gang+ boxes have a lot of wires that need to be spliced together. There are 4 gang in residential too. In commercial I saw an 8 gang once. So is the method of filling a wire nut to it's max with a pig tail daisy chain of more wire nuts what licensed electricians do in new work construction?

I'll work on a schematic diagram of the current state of my switch box wiring vs my future state plan that I stated. Thanks again for your time!

 

[Squidstro]

Here is a schematic of my current state. After diagraming and re-inspecting the wire nut for the hot wires, there are only 4 wires in that 452 nut. Not 6. It's hard to trace all the wires with the twisting. That being said, that nut has room for 2 more wires.

Here is my future state plan with the wafer lights:

I left the grounds out on purpose to not over clutter the diagram. I still have to figure out how to splice 2 more grounds into the 9 existing daisy chain twist/crimp/splice.