Calculating Box Fill Canadian Code

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Jmaclicious
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Calculating Box Fill Canadian Code

Post by Jmaclicious » Mon Mar 25, 2019 11:09 am

When calculating box fill for canadian code.. do ground wires & internal cable connectors count towards volume within switch boxes? I seem to be finding mixed info on this.. I've read in some places it must be deducted One conductor for all grounds, as well as 1 conductor for the internal clamps, but when looking into a canadian edition residential book it doesn't mention internal clamps nor ground wires being counted towards box fill unless the ground wire is actually insulated which would equal almost 50 ML just between those two.

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Re: Calculating Box Fill Canadian Code

Post by Aaron » Mon Mar 25, 2019 12:44 pm

Just use a bigger box than you think you need. lol

I don't think grounds count in NEC (USA) calculations, and I think CEC is probably the same or similar. Emtnut will chime in to confirm.

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Re: Calculating Box Fill Canadian Code

Post by Jmaclicious » Mon Mar 25, 2019 12:52 pm

Aaron wrote:
Mon Mar 25, 2019 12:44 pm
Just use a bigger box than you think you need. lol

I don't think grounds count in NEC (USA) calculations, and I think CEC is probably the same or similar. Emtnut will chime in to confirm.
haha yeah I bought the size up from the 12.5 ones, i got the 14.5 CU ones, couldn't find anything much bigger than that though for single device boxes.

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Re: Calculating Box Fill Canadian Code

Post by Aaron » Mon Mar 25, 2019 2:55 pm

Yeah. If there is obviously ample space and you're not using your foot to push in a receptacle then it's probably ok. Lol

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Re: Calculating Box Fill Canadian Code

Post by emtnut » Tue Mar 26, 2019 5:21 am

Jmaclicious wrote:
Mon Mar 25, 2019 11:09 am
When calculating box fill for canadian code.. do ground wires & internal cable connectors count towards volume within switch boxes? I seem to be finding mixed info on this.. I've read in some places it must be deducted One conductor for all grounds, as well as 1 conductor for the internal clamps, but when looking into a canadian edition residential book it doesn't mention internal clamps nor ground wires being counted towards box fill unless the ground wire is actually insulated which would equal almost 50 ML just between those two.
Ground wires and the internal clamps don't count.

For your 14.5 cu in box, you would be good for 3 #14/2 , with up to 3 marrettes, plus the device (switch or recept).
For larger devices (thicker than 1" like GFCIs and some dimmers) they count as more.

If you need it, Iberville makes a larger box (18 cu) ...http://www.tnb-canada.com/en/fichier/wh ... t_1018.pdf
Or you can always go with a 4 square box with a mud ring.
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Re: Calculating Box Fill Canadian Code

Post by Jmaclicious » Tue Mar 26, 2019 10:54 pm

emtnut wrote:
Tue Mar 26, 2019 5:21 am
Jmaclicious wrote:
Mon Mar 25, 2019 11:09 am
When calculating box fill for canadian code.. do ground wires & internal cable connectors count towards volume within switch boxes? I seem to be finding mixed info on this.. I've read in some places it must be deducted One conductor for all grounds, as well as 1 conductor for the internal clamps, but when looking into a canadian edition residential book it doesn't mention internal clamps nor ground wires being counted towards box fill unless the ground wire is actually insulated which would equal almost 50 ML just between those two.
Ground wires and the internal clamps don't count.

For your 14.5 cu in box, you would be good for 3 #14/2 , with up to 3 marrettes, plus the device (switch or recept).
For larger devices (thicker than 1" like GFCIs and some dimmers) they count as more.

If you need it, Iberville makes a larger box (18 cu) ...http://www.tnb-canada.com/en/fichier/wh ... t_1018.pdf
Or you can always go with a 4 square box with a mud ring.
Awesome thanks ! I just picked up some 16 CU gangable boxes, seems like lots of room now, the dimmer switches I got have a ground screw on them.. if using metal boxes can i just tie all the ground wires together (and also loop to each screw on each section of the connected boxes) and skip doing the whole pig tailing to the 3 switches, or do you think an inspector would want to see the ground wires also attached to the ground screw on the switches?

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Re: Calculating Box Fill Canadian Code

Post by Aaron » Wed Mar 27, 2019 6:08 am

In Canada, the grounding of switches (only switches) are not necessary, regardless of box material. But don't trim the ground wire of any incoming wires--instead, wrap it around a ground screw in the back of the box and fold the excess back there. All those ground screws act as a terminal bus for incoming grounds.

In the US, any device mounted in steel (only steel) boxes does not require a ground wire connected to that device's ground screw as long as the box itself is bonded to ground. All incoming grounds get wirenutted together, along with a pigtail jumper to bond a steel box.

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Re: Calculating Box Fill Canadian Code

Post by emtnut » Wed Mar 27, 2019 11:24 am

Jmaclicious wrote:
Tue Mar 26, 2019 10:54 pm

Awesome thanks ! I just picked up some 16 CU gangable boxes, seems like lots of room now, the dimmer switches I got have a ground screw on them.. if using metal boxes can i just tie all the ground wires together (and also loop to each screw on each section of the connected boxes) and skip doing the whole pig tailing to the 3 switches, or do you think an inspector would want to see the ground wires also attached to the ground screw on the switches?
I've heard that some inspectors here (Ontario) are asking for the ground wire on the switch if it has one.
It's not required, but the argument from the inspectors is that since it is there, it is a manufacturer requirement (I don't personally agree, but if I was getting inspected I'd probably do it ! ).

Some of the dimmers also use the ground wire to light up the switch. That function won't work unless the ground is there.

I'd run a pigtail from each switch to a marrette (which is bonded to the metal box)
The pigtail wires don't count for box fill, only the marrette (if more than one)
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Re: Calculating Box Fill Canadian Code

Post by Aaron » Thu Mar 28, 2019 8:38 am

emtnut wrote:
Wed Mar 27, 2019 11:24 am
I've heard that some inspectors here (Ontario) are asking for the ground wire on the switch if it has one.
It's not required, but the argument from the inspectors is that since it is there, it is a manufacturer requirement (I don't personally agree, but if I was getting inspected I'd probably do it ! ).
The only reason any switch would have ground screws up there is because they're exactly the same switches that are sold here in the U.S. Which makes sense: why manufacture two versions of a switch?

Grounding a switch never used to be necessary in the US. I think that changed in the mid 1980s or so. I remember quite well that switches never used to have ground screws.

Of course we all know full well that all the devices are grounded anyway because you guys most commonly use steel boxes, and even if you didn't, the CSA listed non-metallic ones have ground straps to bond ground to device yokes.
emtnut wrote:
Wed Mar 27, 2019 11:24 am
Some of the dimmers also use the ground wire to light up the switch. That function won't work unless the ground is there.
Oh yes, I suppose so. Quite often dimmers have pigtail leads coming out of them instead of terminal screws (which has always made me wonder why). So if there were a grounding pigtail, I would connect that to ground.
emtnut wrote:
Wed Mar 27, 2019 11:24 am
I'd run a pigtail from each switch to a marrette (which is bonded to the metal box)
The pigtail wires don't count for box fill, only the marrette (if more than one)
You'd connect ground pigtails to ground screws on the switch? I sure wouldn't if I didn't have to. Because while ground wires don't factor into box fill calculation, they certainly factor into box fill in the real world. And the more empty the box, the better in my opinion.

Also, even if I *did* terminate to a ground screw to the switches, I would use incoming ground wires of each leg to do so PER switch, while looping it around a rear ground screw. No wirenuts/marettes necessary... Just imagine the congestion if you had a 4 gang switch: you'd have to wirenut the grounds for all four legs, plus four more pigtails to each switch ground screw, plus a pigtail to bond the box. That's nonsense. The box itself bonds all the grounds together because you guys have boxes with lots of ground screws!

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Re: Calculating Box Fill Canadian Code

Post by emtnut » Thu Mar 28, 2019 10:00 am

Aaron wrote:
Thu Mar 28, 2019 8:38 am

The only reason any switch would have ground screws up there is because they're exactly the same switches that are sold here in the U.S. Which makes sense: why manufacture two versions of a switch?

Grounding a switch never used to be necessary in the US. I think that changed in the mid 1980s or so. I remember quite well that switches never used to have ground screws.

Of course we all know full well that all the devices are grounded anyway because you guys most commonly use steel boxes, and even if you didn't, the CSA listed non-metallic ones have ground straps to bond ground to device yokes.

Oh yes, I suppose so. Quite often dimmers have pigtail leads coming out of them instead of terminal screws (which has always made me wonder why). So if there were a grounding pigtail, I would connect that to ground.

You'd connect ground pigtails to ground screws on the switch? I sure wouldn't if I didn't have to. Because while ground wires don't factor into box fill calculation, they certainly factor into box fill in the real world. And the more empty the box, the better in my opinion.

Also, even if I *did* terminate to a ground screw to the switches, I would use incoming ground wires of each leg to do so PER switch, while looping it around a rear ground screw. No wirenuts/marettes necessary... Just imagine the congestion if you had a 4 gang switch: you'd have to wirenut the grounds for all four legs, plus four more pigtails to each switch ground screw, plus a pigtail to bond the box. That's nonsense. The box itself bonds all the grounds together because you guys have boxes with lots of ground screws!
Actually yes, I think all dimmers have the leads on them. I was thinking of the decora rocker switches that illuminate.

I know it would be silly for the inspector to ask for it... It would also be very difficult for a homeowner to fight him on it.

Closest pic to what I was talking about ... there would still just be the one wirenut. And you could still loop around the switch.
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Re: Calculating Box Fill Canadian Code

Post by Aaron » Thu Mar 28, 2019 10:14 am

What are all those extra ground screws for, then, if not to terminate each incoming ground?

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Re: Calculating Box Fill Canadian Code

Post by emtnut » Thu Mar 28, 2019 10:26 am

Aaron wrote:
Thu Mar 28, 2019 10:14 am
What are all those extra ground screws for, then, if not to terminate each incoming ground?
OP was looking for a bigger box, so I'd think he has 3 cables in a single gang, or 5-6 cables in a double gang. We're one or 2 screws short of a full deck :mrgreen:

This was a change for the 2015 CEC, prior years you had to terminate each incoming ground like you mentioned. If you had more than 2 cables, you couldn't meet the code !
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Re: Calculating Box Fill Canadian Code

Post by Jmaclicious » Thu Mar 28, 2019 7:09 pm

emtnut wrote:
Thu Mar 28, 2019 10:26 am
Aaron wrote:
Thu Mar 28, 2019 10:14 am
What are all those extra ground screws for, then, if not to terminate each incoming ground?
OP was looking for a bigger box, so I'd think he has 3 cables in a single gang, or 5-6 cables in a double gang. We're one or 2 screws short of a full deck :mrgreen:

This was a change for the 2015 CEC, prior years you had to terminate each incoming ground like you mentioned. If you had more than 2 cables, you couldn't meet the code !
So I got annoyed with the gangable box and went back to the welded solid 4 gang box 50 CU IN

At first i tried to pigtail the grounds but because I was using smaller wire nuts i was only allowed 5x 14 wires. and I have 8 ground wires with 20 conductors, the box got quite cramped quickly so instead I cut the ground wires short and fully wrapped them around each ground screw inside the box and I didn't bother pig tailing them to the light switches. I did leave 1 ground a little bit longer with a wire nut on it in case the inspector does want me to pig tail onto the switches. So that cleared up a lot of room since I left the conductors roughly 6" length from the clamps but still had to apply some pressure to get the pushed in. I had to do 3 groups of neutral wires because I didn't feel it was worth to go buy the large wire nut for the 1 splice, 2 groups of 3 with a jumper between, and then the code stair circuit + light together. The nice thing about having the ground wires around the ground screws like that Is I can keep the internal cable clamps a bit loose and it feels more secure.

The hot wires I had a total of 6, and luckily I had a large blue wire nut that fits 6x 14's so I just used that for simplicity sake with 3 pigtail hots going to the 3x 3 way switches.
and then the 3 red wires going to the switches.

I used a multimeter to test the hot leads and check for ground and I was getting 120V. At first I thought being an electrician would be cool.. after pissing around with that box, I think plumbing would be cooler :P Just hoping I dont get an asshat for an inspector...

Also the switches on this 4 gang box were illuminated 3 way rocker switches , but the dimmers I am using dont have ground leads, they just have terminal screw as well. The dimmer switch I picked up wasn't listed if it was compatible or not with the lights but they seem to work, no buzzing, no flickering but if i had to use one with leads id for sure wire nut those.
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Re: Calculating Box Fill Canadian Code

Post by Aaron » Fri Mar 29, 2019 7:07 am

For large bundled splices, I like to use Wago Lever Nuts or Wall Nuts product. That's if I can't use a yellow- or tan-colored wirenut. I typically avoid the red and blue wirenuts, they just take too much space, in my opinion.

Also you need to wrap your ground wires 360 degrees clockwise around the screw, and there can only be one conductor per screw.

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Re: Calculating Box Fill Canadian Code

Post by Jmaclicious » Fri Mar 29, 2019 10:14 am

Aaron wrote:
Fri Mar 29, 2019 7:07 am
For large bundled splices, I like to use Wago Lever Nuts or Wall Nuts product. That's if I can't use a yellow- or tan-colored wirenut. I typically avoid the red and blue wirenuts, they just take too much space, in my opinion.

Also you need to wrap your ground wires 360 degrees clockwise around the screw, and there can only be one conductor per screw.
I was looking at those Wago style connectors, but here they are from Ideal and the local store only carries the in a 4 conductor port but I wasn't sure if they were code in Canada or if the inspectors like those. The wage ones look nice, wish we had access to those! Also yes the ground wires are wrapped 360 degrees c/w around each of the screws.

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Re: Calculating Box Fill Canadian Code

Post by Aaron » Fri Mar 29, 2019 12:55 pm

If it carry a CSA or UL-C listing, you're good.

The screws I'm looking at in your pic are these. It looks like the conductor is just under one side of the screw and not wrapped around 360 degrees clockwise.

An inspector could fail you on that.

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Re: Calculating Box Fill Canadian Code

Post by Aaron » Fri Mar 29, 2019 6:37 pm

By the way, why do you have eight cables entering that box? Are all four switches on separate circuits? It seems they're not because you have two massive splices of both hot and neutral?

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Re: Calculating Box Fill Canadian Code

Post by Jmaclicious » Fri Mar 29, 2019 9:21 pm

Aaron wrote:
Fri Mar 29, 2019 6:37 pm
By the way, why do you have eight cables entering that box? Are all four switches on separate circuits? It seems they're not because you have two massive splices of both hot and neutral?

Sorry mustve been a bad pic angle, but yeah its looped.
I wanted to run the power to the fist switch first, then 14/3 to the other switches, then connect to the lights from there just so all my neutrals stay neutrals for ease of future.

as for the many cables I have from Left to Right
1 - 3 way switch with dimmer at opposing end controlling one zone of basement
2 - 3 way switch with dimmer at opposing end controlling middle lights under duct work
3 - 3 way switch with dimmer at opposing end controlling the opposite zone of basement
4 - Feed for smoke alarm by the stairs, then ill be running a 14/3 to the bedroom for smoke alarm as well.
5 - Feed to the bathroom switch for fan & shower light.
6 - Power coming from storage room switch (The homerun goes to bedroom switch which will have wire to light on dimmer switch, as well as power feed to storage room switch, then from this storage room switch power carries forward to the 4 gang switch by the stairs)
7 - Basement code light
8 - 3 way wire from the upstairs switch for code light (3 way stair light is on another circuit, power going to the upstairs switch first, then 14/3 to this box)

It was mainly the easiest area to run the cables given my bedroom light switch is on a weird/sharp wall angle and because of the low duct work I have no space between where dry wall will be and the duct work as i framed it to be minimal space. I could've fed the bathroom from the storage room switch i suppose but I figure it wouldn't' make much of a difference because I would still be using the same amount of wire nuts anyway.
I used those Multishot cable things so I didn't run out of too much space on the studs (not the end of the world because I am going to be framing another wall in behind there when the hot water tank gets moved), Its rated for 8x 14/2s, or 2x 14/3s.

I used 4x 14/2's on the right side, with a 14/3 beside it under its own S2 staple.

the right side I used 2x 14/3 in the snapshot cable thing with the 3rd 14/3 beside it under its own S2 staple.

For inspection I will disconnect the 3 way switches/dimmer but leave the stair light one installed. But until then I need to see :D
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Re: Calculating Box Fill Canadian Code

Post by Aaron » Fri Mar 29, 2019 10:17 pm

Ok, you got a lot going on in that box. Would someone other than you understand everything in there?

The typical multi-gang switch box will have n+1 cables, where n is the number of switches in the box. The one extra is the feeder of power for those switches.

Seems you're using it as a combo switch and junction box which is legal but not best practice. Typically the topology of branch circuits are a daisy chain; you seem to have a hub-and-spoke thing going on.

I see your ground wire wraparounds. You actually want to do 360 degrees, or a U-turn. You have 540 degrees. :)

This is so the underside of the screw head has flat and even contact with as much of the surface of the conductor as possible. If you wrap it around over itself, it creates a high spot and is actually less secure. I know it's anal but it's best practice.

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Re: Calculating Box Fill Canadian Code

Post by Jmaclicious » Fri Mar 29, 2019 10:42 pm

Aaron wrote:
Fri Mar 29, 2019 10:17 pm
Ok, you got a lot going on in that box. Would someone other than you understand everything in there?

The typical multi-gang switch box will have n+1 cables, where n is the number of switches in the box. The one extra is the feeder of power for those switches.

Seems you're using it as a combo switch and junction box which is legal but not best practice. Typically the topology of branch circuits are a daisy chain; you seem to have a hub-and-spoke thing going on.

I see your ground wire wraparounds. You actually want to do 360 degrees, or a U-turn. You have 540 degrees. :)

This is so the underside of the screw head has flat and even contact with as much of the surface of the conductor as possible. If you wrap it around over itself, it creates a high spot and is actually less secure. I know it's anal but it's best practice.
I could trim the grounds back a bit or put a U-turn on those ground wires for sure! I just left them a bit longer just in case the inspector wanted me to change something up then I could still pull a bit of cable down and still have a decent length of ground to work with.

As for the wiring what would you suggest I change out of that box? Perhaps I could move the smoke alarm feed to one of the other switches instead or wait until I do the storage room lighting and run the feed off of that to the bedroom alarm first, then 14/3 to the second alarm. ( still unsure on what light will be going in there, most likely some wrap around)

Basically my plans are to keep the outlets separate from the lighting esp as I am running 12/2 wire for those, and i was going to put all the lighting on its own 15a circuit, using the Philips FD4 Slim LED lights with the driver box. And I was going to do the smoke alarms on the lighting circuit just in case something was wrong with the breaker or anything I could notice it. That 4 gang box is 50 CU IN, The other device boxes I have on hand are 14.5 & 16 CU IN.
I do have room in the panel so I could change it up if anyway to make it better.

Appreciate the help! :D

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Re: Calculating Box Fill Canadian Code

Post by emtnut » Sat Mar 30, 2019 9:22 am

Jmaclicious wrote:
Fri Mar 29, 2019 9:21 pm

as for the many cables I have from Left to Right
1 - 3 way switch with dimmer at opposing end controlling one zone of basement
2 - 3 way switch with dimmer at opposing end controlling middle lights under duct work
3 - 3 way switch with dimmer at opposing end controlling the opposite zone of basement
4 - Feed for smoke alarm by the stairs, then ill be running a 14/3 to the bedroom for smoke alarm as well.
5 - Feed to the bathroom switch for fan & shower light.
6 - Power coming from storage room switch (The homerun goes to bedroom switch which will have wire to light on dimmer switch, as well as power feed to storage room switch, then from this storage room switch power carries forward to the 4 gang switch by the stairs)
7 - Basement code light
8 - 3 way wire from the upstairs switch for code light (3 way stair light is on another circuit, power going to the upstairs switch first, then 14/3 to this box)
Not sure I follow exactly what the layout is here, but you really shouldn't be using this as a junction box for so many circuits. If some of these circuits are on different breakers, you have to keep the neutrals separate (it will cause the AFCI to trip). Without going thru the calculation, you're about maxed out on box fill ... especially if you need to add a marette or2 to separate the separate circuits.

I'd either do direct runs, or get a separate 4x4 (with a blank cover) and do the splices there.
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Re: Calculating Box Fill Canadian Code

Post by Jmaclicious » Sat Mar 30, 2019 10:18 am

emtnut wrote:
Sat Mar 30, 2019 9:22 am
Jmaclicious wrote:
Fri Mar 29, 2019 9:21 pm

as for the many cables I have from Left to Right
1 - 3 way switch with dimmer at opposing end controlling one zone of basement
2 - 3 way switch with dimmer at opposing end controlling middle lights under duct work
3 - 3 way switch with dimmer at opposing end controlling the opposite zone of basement
4 - Feed for smoke alarm by the stairs, then ill be running a 14/3 to the bedroom for smoke alarm as well.
5 - Feed to the bathroom switch for fan & shower light.
6 - Power coming from storage room switch (The homerun goes to bedroom switch which will have wire to light on dimmer switch, as well as power feed to storage room switch, then from this storage room switch power carries forward to the 4 gang switch by the stairs)
7 - Basement code light
8 - 3 way wire from the upstairs switch for code light (3 way stair light is on another circuit, power going to the upstairs switch first, then 14/3 to this box)
Not sure I follow exactly what the layout is here, but you really shouldn't be using this as a junction box for so many circuits. If some of these circuits are on different breakers, you have to keep the neutrals separate (it will cause the AFCI to trip). Without going thru the calculation, you're about maxed out on box fill ... especially if you need to add a marette or2 to separate the separate circuits.

I'd either do direct runs, or get a separate 4x4 (with a blank cover) and do the splices there.

Sorry ill try to explain, too much over thinking gets me confused haha. My basement has a total of 5 Boxes.
1 For bedroom dimmer switch
1 for storage/mechanical room switch
2 Gang for bathroom exhaust fan/shower & vanity light
4 Gang box which has 2 separate circuits (1 for the 3 way stair light the other for the lighting of basement)
3 gang box at the other end of basement to control the 3 lighting zones on dimmer switches.

The smoke alarm I wanted on lighting circuit so if theres an issue with the breaker id be able to tell if its off, however I know it can't be after the switch so I threw it into this box.


in this 4 gang box I have a total of 2 circuits (neutrals separate)
Circuit 1(All lighting for basement, Power in from storage room, connecting to the 3x 3way switches for the lighting, power out to washroom switch, as well as power out to smoke alarm)
3x 14/3
3x 14/2
Circuit 2 (Stair switch/light):
1x 14/3
1x 14/2

I have 3 nuts for neutrals as I had to wire nut a total of 8 neutrals (2 wires for the stair cct on its own nut) then I had 6 neutrals left but my wire nut only allows for 5 wires, so I split it with a jumper wire.

I have 2 power feeds,
one I have the basement stair light connected to the switch directly
the other is the power wire from the storage room switch which is nutted to the bathroom switch wire, smoke alarm wire, as well as 3 pig tails for the 3x 3 way switches (total of 6 black wires in a large blue nut that I had randomly which allows 6x #14 wires)
The grounds instead of pig tailing them all together I just ran it to each ground screw in the box to cut down on space.

4x 3 way switches (total 8 conductors)
20 wire conductors
4 wire connectors (3 smaller ones, 1 larger one)

28 conductors x 24.6 ml = 688.8 ML plus wire connectors (It says pair 2 or 3 counts as one wire), If i calculate at 2 wires it would be 49.2 ML, however to be extra safe Ill add 5 additional wires. (5 x 24.6 ml = 123 ml)
688 + 123 = 811 ml
according to this 50 CU 4 gang box it would be around 819 ML & if I did it based on the 2 wires for the nuts it would be at approx 761 ml. (if I did this right).

I could use a 4x4 square box hidden neatly up in the joist and label the plate for identification
I could run power there first, then run a total of 5 feeds, a feed to the 4 gang switch, a feed to the bathroom switch, feed to smoke alarm, feed storage room switch and feed to bedroom switch. Would be a lot more wire but if its best I will do that. I guess the best way to do this would be like this? Running each feed from the box to its own switch and smoke alarm then i can keep them labelled for easy identification in the junction box so future home owners can tell what is what. If I do this and take out the wires in the current 4 gang box will I have to replace the box as the pryouts will be missing or would it be fine.
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Re: Calculating Box Fill Canadian Code

Post by emtnut » Sat Mar 30, 2019 11:47 am

Jmaclicious wrote:
Sat Mar 30, 2019 10:18 am


in this 4 gang box I have a total of 2 circuits (neutrals separate)
Circuit 1(All lighting for basement, Power in from storage room, connecting to the 3x 3way switches for the lighting, power out to washroom switch, as well as power out to smoke alarm)
3x 14/3
3x 14/2
Circuit 2 (Stair switch/light):
1x 14/3
1x 14/2
This makes sense to me now.

Personally, I'd ditch the separate 'power out' to the washroom switch and smoke alarm. Just pick up those 2 circuits from the closest lights (of the same circuit)

That will clean up your box a bit.
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Jmaclicious
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Re: Calculating Box Fill Canadian Code

Post by Jmaclicious » Mon Apr 01, 2019 1:58 pm

emtnut wrote:
Sat Mar 30, 2019 11:47 am
Jmaclicious wrote:
Sat Mar 30, 2019 10:18 am


in this 4 gang box I have a total of 2 circuits (neutrals separate)
Circuit 1(All lighting for basement, Power in from storage room, connecting to the 3x 3way switches for the lighting, power out to washroom switch, as well as power out to smoke alarm)
3x 14/3
3x 14/2
Circuit 2 (Stair switch/light):
1x 14/3
1x 14/2
This makes sense to me now.

Personally, I'd ditch the separate 'power out' to the washroom switch and smoke alarm. Just pick up those 2 circuits from the closest lights (of the same circuit)

That will clean up your box a bit.
In order to do that though I wouldn't be able to maintain a neutral in the switch boxes if I tapped off the light without rewiring would I? Since i Have 14/2 power going to the first 3 way switch, a 14/3 across to the next 3 way switch, and then a 14/2 to the first light, daisy chaining each LED driver with 14/2. Maybe just easier to do the Junction box in the storage room to maintain the neutral in the switches? :oops:

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Aaron
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Re: Calculating Box Fill Canadian Code

Post by Aaron » Tue Apr 02, 2019 9:56 am

If all the power to the switches are on the same circuit, then you only need one neutral conductor for the whole box.

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emtnut
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Re: Calculating Box Fill Canadian Code

Post by emtnut » Wed Apr 03, 2019 12:06 pm

Jmaclicious wrote:
Mon Apr 01, 2019 1:58 pm

In order to do that though I wouldn't be able to maintain a neutral in the switch boxes if I tapped off the light without rewiring would I? Since i Have 14/2 power going to the first 3 way switch, a 14/3 across to the next 3 way switch, and then a 14/2 to the first light, daisy chaining each LED driver with 14/2. Maybe just easier to do the Junction box in the storage room to maintain the neutral in the switches? :oops:
Yes, if all your lights are switched (no always hot wire) then you can't do that.
You may be able to feed the smoke from another switch box thou ??

From your numbers you're not over box fill, but it seems overcrowded. If you can get at least one or 2 wires out of there it would be easier to work with.

Nothing wrong with a junction box in the storage room, or just a separate run to the smokes.
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Shannon
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Re: Calculating Box Fill Canadian Code

Post by Shannon » Sun Apr 07, 2019 11:26 am

Could you do a Junction box on other side of that wall in storage room? That would clean up that gang box.
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emtnut
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Re: Calculating Box Fill Canadian Code

Post by emtnut » Sat Apr 27, 2019 6:27 pm

Jmaclicious wrote:
Tue Mar 26, 2019 10:54 pm
.. if using metal boxes can i just tie all the ground wires together (and also loop to each screw on each section of the connected boxes) and skip doing the whole pig tailing to the 3 switches, or do you think an inspector would want to see the ground wires also attached to the ground screw on the switches?
Hope you get back here when your inspection is done !

You should be under 2015 code, but I know some inspectors are asking for ground wires on the switches if the ground terminal is on the switch.
It's actually required under 2018 CEC.

Hope it went well, and you can update us !!
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