RBM wrote:
On 3/18/2013 4:45 PM, TomR wrote:
I just had some new 100-amp electric service panels put in by a
licensed electrician. One is a new house panel in the basement
where the old panels were located, and the other two are in the
upstairs apartments (one in each apartment). The new house panel is
in the basement where there used to be two old panel boxes. The
individual circuit wiring for each of the two new upstairs apartment
panels drops down to where the two original panels were located and
each circuit is tied in there. That leaves all of the house wiring
as it was before, but connects the old circuits to the new panels. Rather
than use the original old panel boxes as junction boxes, the
electrician created new smaller junction boxes there by starting
with a regular metal 4-inch junction box and then stacking one or
two 4-inch metal box extenders on top of that to create a larger
junction box. And then, of course, there is a metal cover plate.

To be clear, here are 3 photo links showing the basic junction box
type that I mean, plus the metal box extender, and the metal cover
plate:
http://www.grainger.com/Grainger/RAC...050?Pid=search
http://www.grainger.com/Grainger/RAC...VU4?Pid=search

http://www.grainger.com/Grainger/RAC...BaseItem=5A050



When I look at the newly-created junction boxes, it looks to me like
they don't quite fit together too well and there are some visible
gaps (maybe 1/16 to 1/8 inch max) between the stacked boxes. I am
wondering if that may be considered a problem since theoretically
there could be sparks inside the junction box sometime in the future
and maybe the box wouldn't fully prevent the sparks from exiting the
box. I, of course, do have a permit and I am about to call for the final
inspection. I will be there for the final inspection that will be
done by the electrical subcode official.

Here's my question:

If by chance the inspector says the gaps are not acceptable, would
it be possible and acceptable to solve that problem by just wrapping
the boxes with several layers of metal aluminum tape -- maybe even
high temperature aluminum tape? My plan would be to have the metal
tape there with me just in case, and if it is okay with the
inspector, just wrap the boxes quickly while he is still there so he
won't have to come back and re-inspect. I know it is up to the inspector,
but I am just wondering if anyone
has ever done this, or if sealing metal junction boxes with metal
aluminum tape is ever done and considered acceptable.

The extension boxes never fit tightly together so I doubt the
inspector will have an issue with that. If the electrician needs to
stack that many boxes together to achieve proper box fill, he should
be using a different box or a small trough. Doing what he did will
make it really difficult to access any of the splices made in the
first box, not to mention being an eye sore. If there is no other
violation found, IMO doing this doesn't meet Nec 110.12 " electrical
equipment shall be installed in a neat and workmanlike manner"

Thanks. That's good to know. Hopefully, I won't get gigged on that and I
can move on from there.