Box fill Guesstimate FUN!

Originally Posted By: jremas
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Here is a previously posted photo of a pancake box. We all know that there is not enough wire coming out of the box, BUT, I would like everyone to take a guess how many wires are allowed in the box and what the total amount will be when they install the fixture that I am providing a picture of. To help out, if you look closely, you will notice that the box is marked 8.0cu. Good luck.


![](upload://wEX8nD7wpMEoH4iJBHfaJeDPRCi.jpeg)

Fixture to be installed:

![](upload://aVGD26OxzxwkKIjmIvfSq7QDS7c.jpeg)

I don't see a fixture stud or hickey. What's your call?


--


Jeff Remas
REMAS Inspections, Inc.
Northeastern PA & the Poconos
www.NEPAinspector.com

570-362-1598

Originally Posted By: jfarsetta
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Looks like 8 wires in the box: 2 ground conductors, 3 hot conductors (total), 3 neutral conductors (total).


I've typically seen pancake boxes on home exteriors, rareely on applications like this one...


--
Joe Farsetta

Illigitimi Non Carborundum
"Dont let the bastards grind you down..."

Originally Posted By: jremas
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Joe, sorry but you are incorrect for box fill calcuations. If what you said was correct, this box would be WAY undersized.


Don't forget.....the equip. gnd is only counted once.
......................fixture wires are not counted.

try again


--


Jeff Remas
REMAS Inspections, Inc.
Northeastern PA & the Poconos
www.NEPAinspector.com

570-362-1598

Originally Posted By: rmoore
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Jeff?


I?m assuming that is 12AWG (as it?s yellow). I see a red wire?is that 12-3 NM? If so you would have 4 12AWG conductors entering, each requiring 2.25 cu in or 9.0 total. Doesn?t matter if one of them is just terminated, the box is too small. I can?t figure out whether the strap comes into play, but it doesn?t seem to matter as it?s already over the limit.

If in fact it is only 12-2 NM then maybe 314.16(B)(4) comes into it but, as it starts out ?For each yoke or strap containing ![icon_question.gif](upload://t2zemjDOQRADd4xSC3xOot86t0m.gif) one or more devices or equipment?? I just get confused reading it. Someone want to explain that paragraph?


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Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com

Originally Posted By: Bob Badger
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Looks like 12/3 to me too.


1 red

1 black

1 white

1 ground

Each requires 2.25 or 9 cubic inches total required.

If 14/3 the total would be 8 ci.

There are no fixture studs, device yokes or straps, internal clamps.

As has been said fixture wires are not counted.

But is that fixture marked with a volume allowance?

Quote:
314.16(A) Box Volume Calculations. The volume of a wiring enclosure (box) shall be the total volume of the assembled sections, and, where used, the space provided by plaster rings, domed covers, extension rings, and so forth, that are marked with their volume or are made from boxes the dimensions of which are listed in Table 314.16(A).


The yoke or strap part of 314.16 just means when a switch or outlet is installed in a box you will add two more volumes equal to the conductors connected to that device.


--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

Originally Posted By: rmoore
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Bob or Jeff…


The limits on box fills is to prevent excessive heat build-up...correct?

In this "terminal" application it seems somewhat odd that 14-3 would be OK but 12-3 puts it over the limit. Seems that there would actually be a little less heat with the larger conductors (assuming the same bulb sizes etc). Of course this isn't something we would normally get to see during an inspection, but I doubt that I would get very excited even if I knew it existed.


--
Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com

Originally Posted By: jremas
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What you see is what you get, this is an actual photo of new construction. What the hell would be the purpose of 12/3 terminating in the box all by itself, I’ll never know.






Jeff Remas
REMAS Inspections, Inc.
Northeastern PA & the Poconos
www.NEPAinspector.com

570-362-1598

Originally Posted By: Mike Parks
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Jeff


This (or that) is a PF pie box.

The "extra" red wire is so that the fan and light can be switched seperately.

I would not fail that install the first time but would tell the "installer" that it would fail on the next home.

Mike P.


Originally Posted By: jremas
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Mike Parks, thanks for the reminder about a switched fan, I was not even considering it initially because this box is mounted in a small hallway. With the fact that we now have 12/3 where 14/3 would have been needed in a lighting circuit, the box fill is now over the rating and YES, it does fail the code rules.


I agree with some the 1st time leniency though....


--


Jeff Remas
REMAS Inspections, Inc.
Northeastern PA & the Poconos
www.NEPAinspector.com

570-362-1598