JJ wrote:

Hi,

I have installed a surface mount 125 A combination meter main. I have
brought all my home runs, 14 of them, all except 2 are 14-2 NM cables
through two 1 1/2" knock outs from the back into the panel with a chase
nipple. Before entering the chase nipple all cables are stapled to the
stud where the panel is mounted. NOW, here is my problem, the inspector
now all of the sudden doesn't accept that (used to be accepted by him
and others just weeks ago) tells me to run them through a gutter and no
more than 2 NMs in a single connector and refers to article 312.5 in
NEC.

I am hoping for help here, there are only few knock outs at the bottom
of the panel, this a Murray 125 A surface mount panel (JA2442B1125SEC)
and of course being a surface mount all are outside. My only other
option is to have min. 7 knock outs in the back of the panel, that is
to punch them, which might be another problem. The inspector could
claim that I am not allowed to punch holes there. Siemens/Murray are of
absolutly of NO help. I will think twice before using their stuff
again.


Does outside mean it is raintight made for exposed outside installation?
Are you mounting it weather exposed? If yes the KOs generally have to
be below the interior guts.

How are you guys installing these panels with home runs or having NMs
coming into them, they got place for 24 full size breakers. Somebody
must have thought about this, it can't be that every of these panels
needs a gutter. Again your help is very mich apprerciated. By the way
the NEC referrence is the one on 2004.

Thanks

JJ


PS: someone else had this question before but I couldn't find any
answer to it.

"While pawing through the 1999 NEC (the one the county inspects to) I
found
that 373-5(c) no longer allows the arrangement in the current box, all
of
the NM cables coming in through a single opening with a bushing in the
back
of the box.

So two questions, please.

First, what is the preferred method for bringing NM loads into a box
like
this? 20 or so individual cable clamps seems bad, and I don't get how
the
exception for one or more 18" conduits into the top of the panel is
supposed to work."


I agree with the inspector that using a chase nipple is a code
violation. There are NM connectors that can connect 2 2-wire NMs through
a 1/2" KO and that would require 7 KOs as you said. If you need to add
any KOs, ask the inspector if that is acceptable. I would think it would
be if they are at the bottom away from the interior guts. Can you use
side/bottom KOs?

The point of conduit entry 18" into the top of a surface mount box is
to protect NM as it runs down a wall. For example for a surface mount
receptacle on a concrete wall you can run 1/2" EMT from the box up into
the protected ceiling area and run the NM through the EMT into the box.
The EMT protects the NM and gives a clean look. There are some other
installation requirements - I'm assuming you have a copy of the code. I
don't know as how I'd bet that many NMs in a single EMT would be acceptable.

bud--