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Posted By: Admin Box Fill? ... This Box is Full! - 01/14/03 12:38 AM
[Linked Image]

#1: I believe most of this is 14AWG. There might be some 12AWG, bottom left.

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#2: Is it permissible to loop conductors around the screws as is shown here? The top has third conductor, barely under the screw.

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#3: A little movement and the conductor came loose.

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ThinkGood
Posted By: lighthouse Re: Box Fill? ... This Box is Full! - 01/14/03 01:45 AM
3 wires under one terminal..that's a no no.

i have seen this practice many times were a single conductor is wrap around 1 terminal

the white wires on the switch is not marked with black tape. this is a hot conductor.

i hope this box had an exstention ring.that adds to the total cubic inch of the box

and where are the grounds from the 2 romex cable.
Posted By: SvenNYC Re: Box Fill? ... This Box is Full! - 01/14/03 02:20 AM
I don't see an extender ring....

Was this four (two duplex) switches in one 4 x 4?
Posted By: HotLine1 Re: Box Fill? ... This Box is Full! - 01/14/03 02:33 AM
Now think about this; how else could you make up that box, if the boss only gave you ONE WIRENUT??

That's all I see.
BTW; it looks like the ground conductors from the NMC are "there", but there is no ground screw/clip visable.

A lot of effort went into putting that mess together.
John
Posted By: ga.sparky56 Re: Box Fill? ... This Box is Full! - 01/14/03 02:44 AM
That looks like its been there awhile. If I did that there would be a fire in about 2 days! Or less.
Posted By: ThinkGood Re: Box Fill? ... This Box is Full! - 01/14/03 04:19 PM
OK, OK, here's the story.

[Linked Image] THIS WAS IN THE DETATCHED GARAGE AT MY HOUSE WHEN I MOVED IN! [Linked Image]

(Sorry for shouting.)

Can you believe it? No, there was not an extender on the box. There was a duplex switch (am I using the correct term) on the right--a switch over a switch. To the left was a 3-way. This whole mess follows underground back to the house where the second 3-way switch is located.

There also had been a duplex receptacle further down the line, which had a strange characteristic: Plugging in a device in the top receptacle disabled the bottom one.

When I opened up the device, I found some spider eggs in there. I wonder if that had something to do with it.

Yes, it does appear that somebody spent quite some time putting it all together.

Here's how it was grounded:

[Linked Image from 65.108.216.53]

It appears to me that the bare wire is of a smaller gauge than the others.
Posted By: ThinkGood Re: Box Fill? ... This Box is Full! - 01/14/03 05:26 PM
lighthouse: As to the practice of looping the conductor around (that is, removing some insulation without cutting the conductor) -- was that ever OK as per the NEC?
Posted By: resqcapt19 Re: Box Fill? ... This Box is Full! - 01/14/03 06:09 PM
I don't know of any code rule that says you can't loop a wire around the screw terminal of a device and continue to another device. This practice was, at one time, required by the specs for a major fast food chain for the outlets that served the cash registers.
Don
Posted By: lighthouse Re: Box Fill? ... This Box is Full! - 01/14/03 08:15 PM
ThinkGood...i did not find anything in the code book saying you can or can not do this.the only thing i found on this is article 110-14-a ...i do see this done all the time in old res wiring(knob and tube)the wire comes into the box around the screw and off to the next sw/rec with about 2/3 inches of wire in the box.it's allway fun trying to change the sw or rec.
Posted By: ElectricAL Re: Box Fill? ... This Box is Full! - 01/15/03 04:42 AM
ThinkGood,

The reduced ground wire dates that piece of romex (is it UF?) to the mid '60s.

Al
Posted By: lwinter31 Re: Box Fill? ... This Box is Full! - 01/15/03 07:06 AM
Box Fill?
Just for fun I figured it.
(guessing from the pic)
4 x 1 1/2sq box = 21 cubic in.
10 #14's (10x2) = 20
2 #12's (2x2.25) = 4.5
2 #16gnd's (1x1.75) = 1.75
2 devices (4x2.25) = 9
Total = 35.25
Slightly overfilled!
BTW I see 2 wirenuts, that make 8 or 9 counting all of us critiquing this box.
Posted By: ElectricAL Re: Box Fill? ... This Box is Full! - 01/15/03 01:49 PM
lwinter31,

As one wirenut to the rest. . . [Linked Image] . . ., remember, the box was calculated (if it actually was) when devices only counted as one conductor. Deduct 4.5 in³.

The reduced ground was manufactured for compliance with the '62 NEC grounding of all receptacles, but ground wires weren't added to the volume calculation until the '68 NEC was adapted (which is also the same time that the ground wire went full sized). Deduct 1.75 in³.

The cable and BX clamps, together, count as one conductor. Add 2.25 in³.

Adjusted wire space needed: 31.25 in³.

Box capacity is adjusted be (1.) the raised cover that we don't see (in the photo above) adding an additional 7.3 in³ (from Raco catalog).

And, (2.) another interesting twist, 2002 NEC Table 314.16(A), or its equivalent, was not introduced in the NEC until '68, in a totally reworked Table 370-6(a-1). In the '62 NEC, 4" X 1½" box could hold 11 #14 conductors, implying a volume of 22 in³, see '62 NEC Table 370-6(a-1). Therefore, I suggest adding another 1.0 in³ to the box capacity.

Total box capacity = 29.3 in³.

By my calc, the box is overstuffed by 1.95 in³.

Al

Edited for '62 NEC Table 370-6(a-1)

[This message has been edited by ElectricAL (edited 01-15-2003).]
Posted By: lwinter31 Re: Box Fill? ... This Box is Full! - 01/15/03 08:11 PM
Thanks Al
I gotta find some of the 60's & 70's codes.

I smooth forgot to calc the raised cover.

I thought the connectors were not counted if the "clamp" was outside the box. Was this different in past codes also?

Larry
Posted By: maintenanceguy Re: Box Fill? ... This Box is Full! - 01/16/03 12:34 AM
I they didn't want you to put in so many wires, they wouldn't make em' with so many knockouts!
Posted By: ThinkGood Re: Box Fill? ... This Box is Full! - 01/16/03 01:14 AM
Yep, it had the raised cover.

Thanks for the info on the smaller ground conductor--I recall reading about that in Old Electrical Wiring Maintenance and Retrofit by David E. Shapiro.

This seems a good example of how the NEC has evolved from the 60s through the current edition.

ElectricAL: you get first prize for all of the calculations and references to the '60s codes. [Linked Image]

Question about counting the clamps in the box fill:

Are you saying that the BX clamps and the two Romex clamps on the bottom, in toto equal one conductor? I know that such is the case relative to ground conductors.

Also, were the burial depth requirements for UF any different in the mid 60s?

Do any of you try to re-use the armored cable in such situations? (If that is permitted per NEC, that is.)

This reminds me of those "guess how many marbles are in the jar" contests.

P. S. lwinter31 is the runner-up, for now. I will need to count conductors out and double-check the AWG to verify [Linked Image]
Posted By: ElectricAL Re: Box Fill? ... This Box is Full! - 01/16/03 04:05 AM
Larry

Thanks, the clamp outside the box doesn't count. So the space required for the conductors drops by 2.25 in³ to the new adjusted total of 29.0 in³. Can ya dig it! The box has 29.3 in³ capacity [Linked Image]. . .it's "not over filled"!!!

Al
Posted By: electure Re: Box Fill? ... This Box is Full! - 01/16/03 01:14 PM
I still wrap conductors around the terminals without cutting them in the case of multiple devices in a box. One less splice, one less wirenut to contend with. (Mine don't come loose, though).
I used to keep track of the # of wires I'd seen in boxes. The record was 32-#12 in a 4Sx1-1/2, with a blank "sort of" on it.(not installed by me of course) [Linked Image] I quit ordering 4S-Spl boxes for the crews because of their tendency to pervert them.
Posted By: ThinkGood Re: Box Fill? ... This Box is Full! - 01/17/03 06:51 AM
electure:

That box with 32 #12s in it should have had a warning about the cover flying off when opened [Linked Image]
Posted By: Bjarney Re: Box Fill? ... This Box is Full! - 01/17/03 10:58 PM
Are 4-square extension boxes OK to be "stacked"?
Posted By: pauluk Re: Box Fill? ... This Box is Full! - 01/18/03 12:04 PM
Code aside, I don't see a problem with wrapping a conductor around the terminal screw uncut, and continuing to another device. The terminal was designed to securely clamp a single conductor, and that's all it's doing.

The extra black wire that somebody's tried to add is a definite no-no, however.
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