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Network box cord feed

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tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
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Master Electrician
This is a Hoffman NEMA 1 box, if there was a plug strip mounted outside with network switches plugged in, its no different than a Hoffman network cabinet, internal 19” mounts and plug strip for 19” rack. Both are boxes hung on the wall, listed box, plug strip, etc, IMO OK.
But hard wiring extends the premises wiring into the box
Using a bubble cover with a small lock for the cord eliminates the concern about it unplugged
And there are locking handles available.
 
Then I'm circling back to still not seeing the OP's application as a substitute for permanent wiring.

Is there a reason the cabinet's power source should not be unplug-able?

Suppose the exact same cabinet and its contents were just sitting on the floor, not attached to the wall.

What permanent wiring method would be suitable for a movable cabinet?
Ok but even ignoring that "not a substitute for permanent wiring" clause, how would you qualify this under "uses permitted"? Seems like I keep asking that and you don't answer.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Ok but even ignoring that "not a substitute for permanent wiring" clause, how would you qualify this under "uses permitted"? Seems like I keep asking that and you don't answer.
I don't really have a direct answer. Not every cord use fits within one of the two permitted/not-permitted lists.

We generally view the NEC as allowing that which is not specifically prohibited. I don't see the prohibition.

Obviously, both sides of this discussion have their merits, or else we would not be having it, like most of them.


How do TV inlet/outlet kits get away with using rubber extension cords instead of NM for the in-wall portion?


 
I don't really have a direct answer. Not every cord use fits within one of the two permitted/not-permitted lists.

We generally view the NEC as allowing that which is not specifically prohibited. I don't see the prohibition.

Yeah I do have significant disputes with the structure of the code here. I don't like the "uses permitted" section, particularly when there is already a "uses not permitted" section, but it is what it is and I don't see how we can ignore the "uses permitted section"

I'm not sure about those in wall tv cables, seems like they would not be NEC compliant, but I see them a bit differently if they are installed by a homeowner in their house and are not part of any permit and inspection, vs the OP's setup that was presumably filed wired by an electrician.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
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PE (Retired) - Power Systems
I don't really have a direct answer. Not every cord use fits within one of the two permitted/not-permitted lists.

We generally view the NEC as allowing that which is not specifically prohibited. I don't see the prohibition.
If these two sections were all inclusive we would only need one of them. You need a complete list of unacceptable or a complete list of only acceptable.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
How do TV inlet/outlet kits get away with using rubber extension cords instead of NM for the in-wall portion?

There is a cord and plug that connects the inlet to the regular wall receptacle. But yeah, don't ask me how LeGrand gets around running flexible cord in a wall from the inlet to the outlet.

If you look closely at that Epic kit, it looks like it actually uses a length of NM with a plug molded on one end. The installer strips the other end and connects it to the outlet behind the TV which is like a mobil home receptacle- no box. So that one is OK.

-Hal
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Were just discussing if you he can use a listed powerstrip inside the NEMA1 enclosure right?
I would think thats OK,
But if its say you fabricate your own power-strip assembly and supply it with flexible cord, attached to the wall that would be "substitute for fixed wiring of a building"
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
But if its say you fabricate your own power-strip assembly and supply it with flexible cord, attached to the wall that would be "substitute for fixed wiring of a building"
I still don't see why a field-assembled cord-and-plug is a substitute for fixed building wiring when a factory-assembled cord-and-outlet wouldn't be, especially in an installation where fixed wiring would not be used.

In other words, why does that cabinet require a fixed wiring method?
 
I still don't see why a field-assembled cord-and-plug is a substitute for fixed building wiring when a factory-assembled cord-and-outlet wouldn't be, especially in an installation where fixed wiring would not be used.

In other words, why does that cabinet require a fixed wiring method?
Because there doesn't seem to be an allowance for it in uses permitted in article 400. Note that in the scope of article 310, it states that the article does not apply to conductors that form an integral part of equipment..... I would say article 400 needs an analogous statement to clarify it does not cover chords on factory listed equipment
 

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
Ok but even ignoring that "not a substitute for permanent wiring" clause, how would you qualify this under "uses permitted"? Seems like I keep asking that and you don't answer.
The "Uses permitted" as found in chapters 1 thru 4 can be modified or change by requirements in chapters 5 thru 8. I don't see OP has fully defined what the panel he is wireing is for but up looks like it might fall into a chapter 7 or 8 that might allow cordage for wiring. This entirly dependent on the what exactly he is building.
 
I think it needs a clearer statement about exactly what we're discussing here.
If the NEC applies to the cord, than it seems pretty clear to me it's not permitted (unless as mentioned Post number 7 you apply number 6 7 or 8, but again those seem like a stretch to me). The way I see it your only shot at compliance is if the NEC somehow doesn't apply to this cord set.
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
I have had to be part of walkthrus of a facility with a fire marshall where they test the egress lighting and they look at tags on extinguishers etc. Basically if they see an 'extension cord' fastened to a wall or going thru a hole in office dividers, under a door, under carpet or up a drop ceiling etc they flag it as a NEC violation.
But this is a equipment rack / NEMA 1 enclosure with a power strip being used according to its listing thats legal.
If they strap that cord to the wall it would get flagged.
If they use a 6 foot extension cord to feed the power strip it would get flagged.

EDIT: They actually have a little handout flyer about cords and power strips they give out.
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
Aren't power strips "relocatable power taps" which implies portability/severability? I've heard that power strips can have key holes for mounting because they quickly allow disconnection, whereas a hole with a screw holding it in place makes it more permanent so they can't have those. Rackmount PDUs are listed under a different UL article than power strips (but the rules seem very similar to me). Not sure if those are allowed to be in "racks" that are bolted to the wall, but I don't see much difference between that and a portable rack on wheels that sits in the corner for years.

Most things with cords are severable or fit one of the exceptions in the code allowing cord. A network or alarm box bolted to the wall seems like permanent premises wiring to me. Whenever we had a network cabinet or alarm box installed in a facility, power was run to it in EMT. There frequently was a normal receptacle box inside the networking or alarm Hoffman box so that the switches or alarm power supply inside the cabinet had a place to plug in.
 
I have had to be part of walkthrus of a facility with a fire marshall where they test the egress lighting and they look at tags on extinguishers etc. Basically if they see an 'extension cord' fastened to a wall or going thru a hole in office dividers, under a door, under carpet or up a drop ceiling etc they flag it as a NEC violation.

I have had similar, however they do not cite any NEC violation. I admit I do not know what code it is, perhaps just municipal fire code or such. They have rules prohibiting extension cords and requiring motors over a certain size be directly plugged in to an outlet.

But this is a equipment rack / NEMA 1 enclosure with a power strip being used according to its listing thats legal.


Yeah just to be clear we are talking about a couple different scenarios. The OP talked of another one that was hardwired with an SO cord. To me that is a lot different than using a listed power strip.
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
I missed the hard wired part, that would never fly around here. You can do that for a cord drop to a pendant where 'flexibility is required' but never into a NEMA1 box.
I have had similar, however they do not cite any NEC violation.
Here there is a state law that inspectors have to cite the precise section of code when they write up violations and 400.12 is very common in office communications closets. Even on new construction, the prints usually only call out for a 20a circuit to a duplex mounted on plywood. Then I go back to meet the inspector and there are like a dozen things plugged in.
I have also had building inspectors want a ground wire pulled to a network rack, I dont remember what code section that was.
 
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