On 3/20/2013 5:07 AM, RBM wrote:
On 3/19/2013 11:53 PM, The Daring Dufas wrote:
On 3/19/2013 7:14 PM, RBM wrote:
On 3/19/2013 7:36 PM, The Daring Dufas wrote:
On 3/19/2013 5:00 AM, RBM wrote:
On 3/19/2013 1:06 AM, Roy wrote:
On Monday, March 18, 2013 2:45:46 PM UTC-6, 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.
Do NOT wrap those boxes with ANYTHING. They must be left AS THEY ARE.
They must be accessible at all times. There should be NO sparks
inside
those boxes EVER. Where did you get that idea of sparks?
If a connection shorts out, or comes loose within the box, there
WILL be
sparks
Hey RBM, when you see a situation where one extension won't satisfy
space requirements, do you do what I do? Mount another box or get a
6x6x4 or 8x8x4 and put everything in there? o_O
TDD
Exactly, if you have that many cables to splice, you use a larger box, a
small trough, or multiple boxes. Id really like to see this multi-ganged
1900 extension set up with cables coming out in all directions like an
octopus.
Some years back, I rewired a building that was being used as a beauty
shop, a very large beauty shop. When a storm blew down a tree which
landed on the drop from the transformer, it broke the hub on the meter
box and sliced the wires like a pair of scissors. It was a 200 amp 3ø
service so after discussing it with the customer, I went back in with
a 400 amp 3ø service and ran the shop off a 65kw diesel generator while
rebuilding the electrical system. I ran all the new circuits overhead
and what I did was come out of the breaker panel with a single 2&1/2"
EMT and elbow to a large screw cover non-gasket junction box in the
drop ceiling and ran my multiple 1/2" EMT 20 amp circuits for hair
dryers and work stations out of that. Not running separate 1/2 conduits
to the panel made changes and additions very easy not to mention the
whole job was easier. My inspector thought it a bit unusual but had no
problem with it and it did make for a much neater installation for the
inside breaker panel. There was a large trough fed with 4" rigid for
the other breaker panels on a wall in the garage area. ^_^
TDD
That makes for a neat installation. I once did a Chinese restaurant like
that. The only issue doing it that way is the requirement to de-rate the
value of the conductors in the 2 1/2" conduit
De-rating was the only issue that came up with the 2&1/2" conduit but
with less than 50% fill it was no problem. That was the reason I went
with the large size. All the conductors would have fit in a 1&1/2" pipe
easily but I went with the bigger pipe to avoid any capacity or wire
pulling hangups. The big junction box in the ceiling made wire pulling
very easy since I was doing most of the work myself. When I teach guys
and gals how to pull wire, I explain that I'm lazy and I want things to
be as easy as possible so I will setup a pull so it can be done by one
person if need be. Most of what I do these days is low voltage telecom
and network wiring and network wiring, especially fiber optic cable is
something to be treated gently. I often spend more time planning a cable
pull than the time it takes to pull the cable in. ^_^
TDD