Electrician Talk banner
1 - 20 of 42 Posts

·
Registered
Joined
·
221 Posts
Discussion Starter · #1 ·
Im new to the trade (grunt worker) and do mostly residential service work in area with a lot of old houses. I come in contact with many overfilled boxes on a daily basis. Most of the time I figured they are grandfathered and I leave them be as long as I am not adding to them..... but I would like to know....

What rule of thumb/guidelines do you use to decide whether to change a box when it exceeds boxfill?
 

·
Retired Account
Joined
·
39,697 Posts
A fair Q mwr....

especially when juxtaposed to g-fathering what's out there

in many of my renos , just introducing a gfci receptacle blows the box fill, due to devicing being two deductions , as opposed to the original one deduction


~CS~
 

·
Registered
Joined
·
13,346 Posts
If I'm just replacing a switch or receptacle I don't mess with it. Adding to an overfilled box I would replace. With the new AFCI rules, you're not going to get that receptacle in a full box. Changes everything.
 

·
Registered
Joined
·
221 Posts
Discussion Starter · #4 · (Edited)
Do you use the number of conductors over as any sort of gauge?

Like 'this ceiling box is 5 conductors over, I better let the homeowner know I need to yank it".
 

·
Registered
Joined
·
13,346 Posts
mwr said:
Do you use the number of conductors over as any sort of gauge?

Like 'this ceiling box is 5 conductors over, I better let the homeowner know I need to yank it".
Five over is a lot for any box (1,2,3 or 4 gang) but most of the time you're in a 1 or 2 gang and good luck getting that back in. If it was one or two, leave it. It also depends what the wiring looks like.
 

·
Registered
Joined
·
6,189 Posts
chicken steve said:
A fair Q mwr.... especially when juxtaposed to g-fathering what's out there in many of my renos , just introducing a gfci receptacle blows the box fill, due to devicing being two deductions , as opposed to the original one deduction ~CS~
Pretty much this. Adding gfi means bigger box or a gfi breaker if it is a dedicated circuit. If it's a bathroom hit from somewhere else I'll just cut the box out, pop in a new one, butt splice the short conductors, and go from there. With AFCIs that is going to end up being the same deal. The chances of fitting an AFCIs breaker in an old loaded up panel is going to be a real challenge versus swapping out boxes.
 

·
NJ-IEC
Joined
·
14,387 Posts
Look for "boxes" in the glossary of the 2011 NEC and you'll see Conductors, number in box. Then it tells ya to look at article 314.16.
 

·
Registered
Joined
·
221 Posts
Discussion Starter · #8 ·
Look for "boxes" in the glossary of the 2011 NEC and you'll see Conductors, number in box. Then it tells ya to look at article 314.16.
Yeah I have that much figured out.... so Magnettica, you follow the chart to the letter while on service calls and if so, what does the homeowner say when you tell them your cutting their walls because they are over by 2 conductors?
 

·
Registered
Joined
·
4,182 Posts
Im new to the trade (grunt worker) and do mostly residential service work in area with a lot of old houses. I come in contact with many overfilled boxes on a daily basis. Most of the time I figured they are grandfathered and I leave them be as long as I am not adding to them..... but I would like to know....

What rule of thumb/guidelines do you use to decide whether to change a box when it exceeds boxfill?
youre new to the trade and youre making the calls in these situations?
 

·
Senile Member
I make all the electrons line up for their Flu shots
Joined
·
33,785 Posts
After 36 years or so in electrical work I am still waiting to find a single box in a dwelling, that has overheated due to too many conductors inside it.


Commercial I see hot boxes all the time, along with hot sections of emt, but I suspect it is due to other reasons.

So I make a macstatement- It is all bullcrap. Fantasyland in a book.
 

·
Retired Account
Joined
·
39,697 Posts
Do you use the number of conductors over as any sort of gauge?

Like 'this ceiling box is 5 conductors over, I better let the homeowner know I need to yank it".

If it's and older wiring method between floors, consider one of these mwr>


~CS~
 

·
Retired Account
Joined
·
39,697 Posts
After 36 years or so in electrical work I am still waiting to find a single box in a dwelling, that has overheated due to too many conductors inside it.


Commercial I see hot boxes all the time, along with hot sections of emt, but I suspect it is due to other reasons.

So I make a macstatement- It is all bullcrap. Fantasyland in a book.
The issue of captive heat in the nec isn't exactly doled out with anything more than benchmarks , which aren't even relevant to each other

~CS~
 

·
Banned
Joined
·
1,246 Posts
Where I live most houses are older and wired with old BX. The original receptacles were 2 prong but over the years they were changed out to 3 prong and the BX's metal jacket was subsequently used as the EGC.

Now we all know the metal jacket on BX is a poor conductor without the bonding strip, but it's still the way it's done.

So basically any receptacle I change out is a violation, unless I install a 2 prong or GFCI.
 

·
Administrator
Retired EC
Joined
·
24,061 Posts
Where I live most houses are older and wired with old BX. The original receptacles were 2 prong but over the years they were changed out to 3 prong and the BX's metal jacket was subsequently used as the EGC.

Now we all know the metal jacket on BX is a poor conductor without the bonding strip, but it's still the way it's done.

So basically any receptacle I change out is a violation, unless I install a 2 prong or GFCI.
and you do what???? :)
 

·
Administrator
Retired EC
Joined
·
24,061 Posts
Install a 3 prong and never think of it again :laughing:

That's the standard thing to do, inspectors know how it is, it's the same in their house.
A 3 prong bonded to the box, I assume? IMO, that can be real dangerous if the bx does not have a bonding wire in it. I would rather not bond it then try to make it worse.

I have seen bx glow from a short that would not clear because of the impedance on the cable. I know that fires have been caused from this exact sitiation
 
  • Like
Reactions: chicken steve
1 - 20 of 42 Posts
Top