Middle-of-Run Electrical Outlet Plus one more question.

[penright]

Helping my inlaws add an outlet for a TV hanging on the wall. It was an easy run, with no insulation or studs to go through. Pulling the wall plate off, it looked like only one Romex was in there and we thought it was an end of a run. After digging in deeper it turned out to be the middle of the run. The electrician used backstabs and we did not see the wire.
The "plus" question first, the existing wires had a yellow tint to them. It was had to get the picture focus so it might be hard to tell, but when the wire we pulled for the new outlet, you can tell the difference. What is this? Different amounts of copper?

The second question with commercial outlets, they have two holes per screw, and that you can use one wire per hole. Is that correct?
Is there a box fill issue? Do they make single-gang deep old work boxes? Should we just wire nut it and put a blank cover?

 

[cmandp]

The resident electricians can advise better but my experience with discolored copper conductors is that they got heated, meaning a bad connection or wire on a larger breaker than it can handle (14AWG on a 20A breaker for example). That makes sense with back stabs. But I would just cut the wire back to where the copper isn't discolored to make your new connections.

If you're talking spec grade "back wire" outlets yes you can use only one wire or up to 2 under each screw.

I'd have to look up box fill to answer that but at Home depot they usually have a shallow and deep old work box yes. One is 14 cu. in. and the deep is 20 I think.

 

[penright]

discolored copper conductors is that they got heated, meaning a bad connection or wire on a larger breaker than it can handle (14AWG on a 20A breaker for example).

It is not a "discolor" per se, just different. And it is not like heat, the insulation does not show any heat.

If you're talking spec grade "back wire" outlets yes you can use only one wire or up to 2 under each screw.

I have never heard that slang before. I know there is a difference between what I understood as "builder" grade vs "commercial" grade.
The "builder" grade has only room for one wire under the screw. Whereas the "commercial" grade has two slots per screw and there are two screws per side and that is why you can join three wires.

I'd have to look up box fill to answer that but at Home depot they usually have a shallow and deep old work box yes. One is 14 cu. in. and the deep is 20 I think.

I bet it was a 14 cu. in. Lowes did not have one in the house, I found the two I needed at a small town Ace hardware. I have found this, count each circuit conductor as it is (14ga=2" 12= 2.25"), but I thought that NM cable was calculated differently.
If that is the case then 3 x 2.25 = 5.67. Then 6.75+6.75+2.25 = 15.75 for wires and 6.75 for the device gets me to 18. If that is right, then I have to find a 20 cu. in. Even a splice of over.

 

[Steve W.]

... = 15.75 for wires and 6.75 for the device gets me to 18.

???

Might want to check your math on this.

I'll admit that my schooling was a LONG time ago, but 15.75 plus 6.75 used to total 22.5.

.

 

[penright]

???

Might want to check your math on this.

I'll admit that my schooling was a LONG time ago, but 15.75 plus 6.75 used to total 22.5.

.

Can I blame that on new math? That was embarrassing.
Other than the fact I can't add, is 22.5 right for 12-2 and one outlet?
@steve w, Good catch, Thank you.

 

[penright]

I think this is my ticket.
B125AB 1-Gang PVC New/Old Work Deep Switch/Outlet Wall Electrical Box, 24.5 cu. in.
If I am looking at the specs correctly, I think it will work in a 2x4 wall. (But I am not doing any math )

I had to watch the video for the application I needed.
Looks like the screws come in from the side.

 

[cmandp]

I get 18 Cu. In. required based on 2 12-2 NM-b coming into the box. So that means the deep old work box is fine.

4 Conductors (4 X 2.25) = 9
1 Clamp = 2.25
1 Device (2 X 2.25) = 4.5
EGCs = 2.25
= 18

All EGCs count as one, use largest gauge in box for volume.

I'll just add that I'm bad a box fill calculations and always have to look it up.

But yes that box will work in a 2X4 wall, I started keeping a few around for situations where you're right up against a stud.

 

[penright]

Getting a little off-topic, what is strange, I can not find any old work boxes of any size in Oklahoma City. That box stores and Locke Supply.
I found one on Amazon.

 

[penright]

4 Conductors (4 X 2.25) = 9
1 Clamp = 2.25
1 Device (2 X 2.25) = 4.5
EGCs = 2.25
= 18

I have 6 (3 2-12 wG Romex).

I did not count a Clamp, but I did count a ground, am I wrong?

 

[cmandp]

Ah, I assumed 2x 12-2 w/Gnd. Then yes looks like 22.5 Cu. In. would be correct.

 

[wyliesdiesels]

Getting a little off-topic, what is strange, I can not find any old work boxes of any size in Oklahoma City. That box stores and Locke Supply.
I found one on Amazon.

not strange at all to those in the industry. there has been shortages going on for a long time now, especially with nail-on and old work plastic boxes. my local big box stores are practically empty and have been for awhile now.