Old House - Boxfill issue

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  #1  
Old 11-15-13, 05:23 PM
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Old House - Boxfill issue

I had to replace an outlet in a bedroom.

House and wiring is 60 years old.

I think the box is a 3 x 2 x 2 1/2 device box which contains:

1 x 14g wire passing thru uncut.
2 x 14g whites with a pigtail to outlet.
2 x 14g blacks with a pigtail to outlet.
1 standard duplex outlet.
There are no grounds.
There is what looks like a nail or bracket passing thru the bottom of the box. All the boxes in the house has these?

I think this counts as 7, and I believe I am over by 1.

Besides the wirenuts and the pigtails which I had to add to install new outlet, this setup has been in place for 60 years.

What should I do?
Is leaving it as is a safety concern?
Is this considered a grandfathered issue in regards to code? Would this boxfill calculation been ok when the house was built?
 
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  #2  
Old 11-15-13, 05:48 PM
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(CEC, NEC may vary.)
Your box is allowed 8 14 AWG wires.

Pigtails don`t count. (so long as they are a reasonable length)
Standard receptacles don`t count. (device must enter the box 2.5cm or more for it to reduce fill.)
Bare grounds (if you had them) don`t count. Only insulated conductors.

Deduct one for the nail.
Deduct one for the set of marettes (every set of 2 reduces the wire count by 1)

You may now put 6 14 AWG wires in your box.

2 white wires
2 black wires
1 pass through
=
5 wires. You are ok.

You say there is a pass through... Is your receptacle piped in?
And as far as code when the house was built, I don't think old guys had any code back in the day. Every place I've worked built before the 80's had a ton of sketchy crap in it. Plus, you're assuming journeyman wired it. Joe Schmo homeowner might have slapped things together himself. My grannies basement was done by the original owner and he wired every light in series ie: turn on basement landing light, then laundry room, then storage room, then you can turn the bedroom light on.
 
  #3  
Old 11-15-13, 09:39 PM
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The NEC calculates box fill in cubic inches. The cu. in. should be stamped inside the back of your box. Take a flashlight and look.

You need a 20 or 22 cu. in. box. Depending on whether that nail thingy is actually a clamp.

Box Fill

Article -*More Wires Need Bigger Boxes - Fine Homebuilding Article

Calculator -*Box Fill

Get back to us with the stamped box size and whether the box is piped in and we'll suggest courses of action.
 
  #4  
Old 11-16-13, 03:14 AM
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Many metal boxes are not stamped with their capacity.

Older box fill rules only added one for the device vs two like today's rule.
 
  #5  
Old 11-16-13, 04:56 AM
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Looks like I am good to go... if the house was in Canada.

The volume isnt stamped on this box. Again its 60 years old. It is "piped" conduit.

2x3x2.5 - 5 conductors. 1 device. 2 wirenuts, 2 pigtails. I assume thats overfilled by 1 increment in the NEC.

So my questions are:

What should I do?
Is leaving it as is a safety concern?
Is this considered a grandfathered issue in regards to code? Would this boxfill calculation been ok when the house was built?

Thank you.
 
  #6  
Old 11-16-13, 09:25 AM
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NEC and CEC are different.

NEC:
One per wire going through the box (no splice)
One per wire that ends in the box
Two per device
one per internal clamp (you have none)
One per all the grounds (you have none)
N/A Pigtails, wirenuts do not count

5 #14 wires + 2 Device = 7
7 x 2.00 Cubic Inch (#14 counts as 2 CI each) = 14CI
3 x 2 x 2 1/2 box has a CI of 12.5

Your overfilled. Either remove the device or install a bigger box, however if you are just changing the device I would say you are grandfathered in.
 
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Old 11-16-13, 09:59 AM
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Your overfilled. Either remove the device or install a bigger box, however if you are just changing the device I would say you are grandfathered in.
I am confused about the technicallity of the grandfathering thing in my 60yo house.

So just adding an outlet isnt the same as a larger undertaking? I added pigtails to the box, does that make it more than an outlet change? In this particular case (overfilled by 1), when would this have been allowed? Was a device ever counted as 1?

Bottom line, is being overfilled by one conductor a safety issue I should be concerned with?


BTW: Im not interested in debating the code or have a discussion why its in place, I know why and respect that...
 
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Old 11-16-13, 11:39 AM
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Personally I would say no, so long as you have no wires compressed between the receptacle screws and the box (on the side).
Since your receptacle is piped in, they probably consider the pipe as being grounded. I personally don't trust that rule on the offchance a coupling came loose behind a wall. You could always pull a ground in if you wanted to.
And the grandfather thing, I believe you're ok just changing the receptacle (I've gathered the NEC requires tamper proof pretty much everywhere?) However if you were ever to tear down drywall to reinsulate or something, I think you are then obligated to replace the box or wires.

Tolyn,
Bare grounds don't count. But lets say the box is piped in with an insulated ground, then it counts.
 
  #9  
Old 11-16-13, 11:56 AM
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adding an outlet
This is the key words. Are you adding an outlet, or are you replacing one that was there? IF you are adding one, you should not put it there and add the outlet in a new location, with a new box. If your just replacing one that has failed, then you would be grandfathered in.

Bottom line, is being overfilled by one conductor a safety issue I should be concerned with?
BTW: Im not interested in debating the code or have a discussion why its in place, I know why and respect that...
Everything that is in the code is there for safety, so yes, overfilling a box is a safety issue.
 
  #10  
Old 11-16-13, 12:00 PM
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Tolyn, I think he is just curious about his scenario.
Code is like law and when doing new work should be followed to the letter. But for work already completed 50 years ago, in this scenario, do you believe being over on box fill by a small amount is dangerous?
Especially since Canada says he is ok but US says he is not. I don't see immediate danger here.
 
  #11  
Old 11-16-13, 12:40 PM
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Many metal boxes are not stamped with their capacity.
Thanks pcboss. I always wondered why table 314.16(A) for metal boxes existed.

Cws05, pinched or crushed wires can break or have their insulation compromised against the metal. Only you were there to see how tight that box was. If you had to force the receptacle in or you can see it bowing out and straining against the screws, then you are definitely doing damage.

This product comes in ivory or white and is paintable.

Wiremold/Legrand, 4.8 in. Starter Box, V5751 at The Home Depot - Tablet

It would add about 12 cu. in. to your box size. And that should definitely be stamped on the inside.

It's a judgement call. Pcboss says devices used to be counted as one. Pigtails are a change, but they don't count for fill. If the device was easy going in then call it grandfathered and be done with it.

On the other hand, adding a receptacle instead of just replacing one is a deal breaker.
 
  #12  
Old 11-16-13, 01:34 PM
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Thanks for your responses.... im still confused though.

FWIW, this was just replacing the outlet (faulty 2 prong to 3 prong).


Tolyn wrote: Everything that is in the code is there for safety, so yes, overfilling a box is a safety issue.
I dont want to turn this into a code debate thing but with that reasoning then the grandfathering thing is invalid right? Like its no longer code, so now its a safety hazard, and hazards need to be corrected regardless. Therein lies the confusion.

Maybe I should have rephrased my question to maybe how 'much' of safety hazard is this?

Or perhaps pose this scenario.... would an electrician, called out on a service call to replace the outlet, immedietly tell the homeowner that he missed the overfill limit by 1 wire and now will need to cut into the wall and install a new box or remove the outlet totally from service?

How about if you found a similar scenario in a box in your house?

Would you immediatly tear into the wall to install a 4" box after 60 years of this being in place? Or would you just remove the outlet all togehter and put on a blank cover or that wiremold dohickey?


Im even more confused, all this for one stinking conductor over the limit!!
 
  #13  
Old 11-16-13, 02:12 PM
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As I said, If you are just replacing the receptacle, you would be grandfathered in. The installation was ok at the time it was installed (we assume )

outlet (faulty 2 prong to 3 prong)
I hope you are properly grounding this 3 prong outlet.

If I was called to a house to change a receptacle in an existing box, I would not bother counting wires and assume it is grandfathered in unless I had a very difficult time getting it to fit in the box.
 
  #14  
Old 11-16-13, 03:18 PM
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I worked maintenance at a hotel that I'm pretty sure was wired by monkeys. Many things were grandfathered in. The general rule I went by when replacing electrical devices was so long as I didn't have to shove the device in and pray a marette didn't come loose, it was ok.
Think of it this way...
At one point your receptacle was likely acceptable. Nobody figured there was danger in your setup, and as I pointed out, your box is acceptable in Canada (we do consider safety important. we don't wire things as you may see in lets say Mexico.) plus, whether Canadian or American, insurance companies don't want to pay out anybody. So if Canada, which is not a third world country, says your box is fine, which insurance companies clearly don't argue, you are in no danger because the NEC says you are one wire over.
You are not tearing apart walls and doing major renos, so you aren't very obligated to replace the wiring and boxes for this.
You are obligated to put in a receptacle that meets today's standards though. Bedrooms require tamper proof receptacles. So put a tamper proof in, and a small piece of ground wire to attach the receptacle to the box. As long as your folded wires fit behind the receptacle, you are in no danger.
And I have found boxes stuffed in the place I currently live. One of them had 10" of wire sticking out of it, and 10" pigtails. I just cut the wires and pigtails down to 6" which is standard and created more room. Marrettes can be changed as well to save a little room. If your box had 33 marrettes (usually yellow) on 14 AWG wire you could safely switch them to smaller 31 (orange) marrettes.
If you run into more grandfathered scenarios in your house, use your best judgement. Can it be replaced easily? Are you comfortable leaving it as is?
 
  #15  
Old 11-19-13, 03:57 PM
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Go ahead and swap the receptacle. Your 2 x 3 x 2-1/2 inch box has 15 cubic inches in it. That's more than you need with #14 AWG wire.
 
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Old 11-19-13, 04:23 PM
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Nashkat1 wrote:

Go ahead and swap the receptacle. Your 2 x 3 x 2-1/2 inch box has 15 cubic inches in it. That's more than you need with #14 AWG wire..
12.5 cubic inches. Maybe in Canada its 15?
 
  #17  
Old 11-20-13, 01:55 PM
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OK Im an idiot... and even more confused.

2x3x2.5= 15

14awg x 5 = 10 + 2 for device = 12

My "Ugly's reference" tells me I can only fit 6 in that box.


huh? Im moving to Canada.
 
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Old 11-20-13, 05:21 PM
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The Table in Article 314 says that box has a minimum of 12.5 cubic inch capacity. You cannot use the actual dimensions, but need to use the chart.

Does you box have internal clamps? If so that is a deduction of 1 conductor.
 
  #19  
Old 11-21-13, 12:32 PM
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PCBOSS wrote: The Table in Article 314 says that box has a minimum of 12.5 cubic inch capacity. You cannot use the actual dimensions, but need to use the chart.
Thats what I thought. But I got the following unfounded response which confused the matter:

Nashkat1 wrote: Your 2 x 3 x 2-1/2 inch box has 15 cubic inches in it. That's more than you need with #14 AWG wire.
Curious, why isnt the actual dimensions used?
 
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Old 11-21-13, 05:35 PM
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I am not sure why the difference. Might be to account for slight differences. The chart says minimum capacity.
 
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Old 11-21-13, 09:44 PM
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I am not sure why the difference. Might be to account for slight differences. The chart says minimum capacity.
And I don't have my copy with me at the moment, so I can't get into that part right now. I know I've used - we've used - the box dimensions on every job for years and never failed because of it, so that's what I go with.

That doesn't mean it's correct. It only means that we've never been questioned on it.
 
  #22  
Old 11-23-13, 07:17 AM
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I know I've used - we've used - the box dimensions on every job for years and never failed because of it, so that's what I go with.

That doesn't mean it's correct. It only means that we've never been questioned on it.
Its not very responsible to knowingly give erroneous advice either.
 
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Old 11-23-13, 07:29 AM
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Late to the discussion and not a pro but could the angled backs of gangable boxes be a factor or is that not the type of box being discussed?
 
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Old 11-23-13, 11:03 PM
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ts not very responsible to knowingly give erroneous advice either.
No, it isn't. Why, do you think I did that?

Here's something I didn't know before:

[314.16 Number of Conductors in Outlet, Device, and
Junction Boxes, and Conduit Bodies.


(A) Box Volume Calculations.

(1) Standard Boxes. The volumes of standard boxes that
are not marked with their volume shall be as given in Table
314.16(A).

[SUB]Source: National Electrical Code[SUP][/SUP], 2011 edition[/SUB]
So, cws05, your 2 x 3 x 2-1/2" box has an allowable volume of 12.5 in.[SUP]3[/SUP], unless it has an actual volume marked on it at the factory - which it obviously doesn't.

Hmmmm..... Learn something every day.
 

Last edited by Nashkat1; 11-23-13 at 11:26 PM.
  #25  
Old 11-24-13, 07:40 AM
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That was my point that the chart vs actual math could have slight differences.
 
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Old 11-24-13, 12:50 PM
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That was my point that the chart vs actual math could have slight differences.
Right. I saw that and was curious how that was so, so I looked it up when I got home and had access to my code reference again. (I will arrange to have that with me on the read!)

I'm curious, Boss - how did you find out about this? Are the inspectors in your area starting to check it?
 
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Old 11-24-13, 01:27 PM
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Most of my work is resi and using plastic boxes. It was just what i was taught in code classes.

Here is one for you. A 1 1/2 deep 4 square has a chart volume of 21 cubic inches. The math says it should be 24 cubic inches. Makes a difference.
 
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Old 11-24-13, 02:04 PM
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Most of my work is resi and using plastic boxes. It was just what i was taught in code classes.
OK. Another example of different experiences within the brotherhood.

Here is one for you. A 1 1/2 deep 4 square has a chart volume of 21 cubic inches. The math says it should be 24 cubic inches.
Yeah, and a shallow 1900 has a volume of 18 in.[SUP]3[/SUP] in the chart when the math gives us 20 in.[SUP]3[/SUP]. Curious. Especially when raised mud rings count - if stamped.

Makes a difference.
It does. Especially losing 4 in.[SUP]3[/SUP].
 
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