1 members (Scott35),
565
guests, and
35
robots. |
Key:
Admin,
Global Mod,
Mod
|
|
|
Joined: Jul 2004
Posts: 625
Member
|
The "threaded hub" in 314.23(H)(1) is only a suggestion, not a requirement. The requirement is that the conductors be protected against strain. If a connection to a KO accomplishes that, then it is also permitted.
As a note, I have never seen even one pendant around here that uses a box with a hub. I see four-square boxes all over the place.
|
|
|
|
Joined: Jul 2004
Posts: 9,931 Likes: 34
Member
|
I doubt I would take a 4" square box hanging on a regular connector as a pendant. How do you keep the lock nut tight? I'm sure there is a 110.3(B) in there somewhere if common sense isn't enough.
Greg Fretwell
|
|
|
|
Joined: Oct 2004
Posts: 132
Member
|
Stamped steel boxes (4S, 5S, Handy Box, etc) w/ KO's are not for "portable" use. That means you can't make quadboxes, splitters, portable GFCI's etc out of them . The main reason for this is that the KO's bend inward and may touch the device screws, leading to problems. I believe their UL listing covers this...maybe somebody can post this?
|
|
|
|
Joined: Dec 2000
Posts: 4,294
OP
Member
|
I've always wondered why they were called knockouts instead of knockins JBD, My original Q dealt with fastened in place large machinery. I think it is addressed in Article 400. I'm not trying to look at one part of the NEC and not another. Sure I've got my opinion, but I'm trying to understand where I might be missing something. After all, that's what this forum's for. 336.10(7) doesn't seem to have anything to do with cord pendants.
|
|
|
|
Joined: Apr 2002
Posts: 7,382 Likes: 7
Member
|
Electure: I fail to see where in Art 400 you may find a good 'argument' to use cord to connect large machinery.
edit
I just re-read your opening post; OK, you said 'non-movable', so why not RMC/IMC?. Or, as you described it, why not lengthen the 'field installed..." to go 'up' to a suitable twistlock recept?? Or, RGC/IMC down to a suitable box; nipple to floor flange on floor, then a TL in the box?
The usual debate (EC to AHJ) 'physical damage'; the load on the OH crane could hit the RGC; (me) but it can't hit the cord?? 9ec) 'vibration'; (me) OK, use sealtite for the final conn.
As I said above, been there, done it.
John
John
[This message has been edited by HotLine1 (edited 09-28-2006).]
John
|
|
|
|
Joined: Jul 2001
Posts: 599
Member
|
My point is that there are several places in the NEC that allow cords to fixed equipment.
400.7(A) only requires cord connectors for 3 of its 10 possible situations. So it is clear that cords can be used from one utilization device to another.
So another question is "what is a pendant", as it pertains to 400.7(A)(1)? Is it any vertical riser? We know plugs and receptacles are not required, because 400.7(B) does not apply to it.
|
|
|
|
Joined: Apr 2002
Posts: 7,382 Likes: 7
Member
|
JBD:
You stated: "My point is that there are several places in the NEC that allow cords to fixed equipment. 400.7(A) only requires cord connectors for 3 of its 10 possible situations. So it is clear that cords can be used from one utilization device to another.
So another question is "what is a pendant", as it pertains to 400.7(A)(1)? Is it any vertical riser? We know plugs and receptacles are not required, because 400.7(B) does not apply to it."
Your statement regarding 400.7 (A); I cannot understand what you mean!
There is no definition for "pendant" in Art. 100. I know of a 'pendant', as a control station, like for a rolling OH crane with various buttons or switches; in flex cord, into a strain relief connector.
There are probably 'pendant' receptacles, but, I have not seen any.
John
John
|
|
|
|
Joined: Jul 2004
Posts: 9,931 Likes: 34
Member
|
Look at the fryer behind the counter at a burger king. Every one I have seen in SW Florida was supplied by an IEC309 connector from an SO cord pendant.
Greg Fretwell
|
|
|
|
Joined: Jul 2001
Posts: 599
Member
|
Is any vertical drop of flexible cable a pendant and therefore allowed by 400.7(A)(1)? Or, do pendants need to be "free hanging" and only fixed in place on one end?
|
|
|
Posts: 404
Joined: March 2007
|
|
|
|