NEC Confusion

[MrsFooter]

I'm doing a little reading in Mr Harry C Box's section on NEC and I've come across a regulation that as I understand it utterly confounds me. I'm pretty sure that it's reader error, so I'm hoping someone can use smaller words and help me understand where I'm going wrong.

As it reads in Harry C. Box's Set Lighting Technician's Handbook: Third Edition:

"Any wire smaller than no. 8 AWG connected to a paddle or stage box must have appropriate fuses in the connector."

Now, if 'paddle' refers to a male connector as the glossary in the back says it does, wouldn't that mean that all male stage pin connectors on stage at the end of standard 12/3 SOW cable has to have a fuse in it? I've ripped apart a lot of connectors, and I've never once seen one with a fuse in it. Which means that either as an industry we're all looking the other way (not likely,) or (very likely) I'm misreading and misinterpreting this bit of code.

If anyone could better explain this one to me, I would greatly appreciate it. (Extra points for best use of sock puppets.)

 

[DuckJordan]

It's likely refering to cables with 4 and 2 gauge meaning smaller number not smaller physical size.

 

[SteveB]

I'm doing a little reading in Mr Harry C Box's section on NEC and I've come across a regulation that as I understand it utterly confounds me. I'm pretty sure that it's reader error, so I'm hoping someone can use smaller words and help me understand where I'm going wrong.

As it reads in Harry C. Box's Set Lighting Technician's Handbook: Third Edition:

"Any wire smaller than no. 8 AWG connected to a paddle or stage box must have appropriate fuses in the connector."

Now, if 'paddle' refers to a male connector as the glossary in the back says it does, wouldn't that mean that all male stage pin connectors on stage at the end of standard 12/3 SOW cable has to have a fuse in it? I've ripped apart a lot of connectors, and I've never once seen one with a fuse in it. Which means that either as an industry we're all looking the other way (not likely,) or (very likely) I'm misreading and misinterpreting this bit of code.

If anyone could better explain this one to me, I would greatly appreciate it. (Extra points for best use of sock puppets.)

The stage plug and paddles as used in the film industry are not 2P&G "pin" connectors, thus the confusion.

Professional Lighting Handbook - Verne Carlson, Sylvia Carlson - Google Books

 

[meatpopsicle]

It's likely refering to cables with 4 and 2 gauge meaning smaller number not smaller physical size.

Not likely. Smaller wire would denote #10 and smaller, ie 10, 12, 14, 16... .

We, in the film industry, do not use paddle any more. And I'm not sure what their definition of "stage box" is in this reference; there are many types in my end of the business.
I have heard of 100A 2p&g connectors that had fuses in the connector, but I've never seen them (30 years in the business). They are a rarity.

I,too, would like further clarification on the "fuse in the connector" part of this definition. SteveB might be closer to the truth in that these are, perhaps, outdated regs. from the age of Tweco/paddle distro.

 

[MrsFooter]

The stage plug and paddles as used in the film industry are not 2P&G "pin" connectors, thus the confusion.

Professional Lighting Handbook - Verne Carlson, Sylvia Carlson - Google Books

We, in the film industry, do not use paddle any more. And I'm not sure what their definition of "stage box" is in this reference; there are many types in my end of the business.
I have heard of 100A 2p&g connectors that had fuses in the connector, but I've never seen them (30 years in the business). They are a rarity.

I,too, would like further clarification on the "fuse in the connector" part of this definition. SteveB might be closer to the truth in that these are, perhaps, outdated regs. from the age of Tweco/paddle distro.

Ooooooh, that makes more sense. It probably should have dawned on me that they might not necessarily be talking about stage pin, but...well, you ever lose sight of the forest?

Thanks, guys.

 

[derekleffew]

... As it reads in Harry C. Box's Set Lighting Technician's Handbook: Third Edition:
"Any wire smaller than no. 8 AWG connected to a paddle or stage box must have appropriate fuses in the connector."[SUP]1[/SUP]

Page? Section?
I'm guessing Mr. Box is out of date, but referring to NEC 520.57:

...The connector shall be rated in amperes and designed so that differently rated devices cannot be connected together; ...

Plugging two 25/30A paddles (half stage plugs) into a 50A outlet violates the above.

The stage plug fails 406.7:

All attachment plugs, cord connectors, and flanged surface devices (inlets and outlets) shall be listed[SUP]2[/SUP] and marked with the manufacturer's name or identification and voltage and ampere ratings.

[SUP]1[/SUP]One cannot tell from the context whether Mr. Box is using "connector" correctly to refer to only a female device, or in the more general any interconnecting device.
[SUP]2[/SUP]listed, by NRTL

I suspect it's the same reason a "one 2P&G-60A male to three 2P&G-20A female" "adapter" is illegal unless it contains three 20A OCPD s.
.

 

[STEVETERRY]

Page? Section?
I'm guessing Mr. Box is out of date, but referring to NEC 520.57:
Plugging two 25/30A paddles (half stage plugs) into a 50A outlet violates the above.

The stage plug fails 406.7:

[SUP]1[/SUP]One cannot tell from the context whether Mr. Box is using "connector" correctly to refer to only a female device, or in the more general any interconnecting device.
[SUP]2[/SUP]listed, by NRTL

I suspect it's the same reason a "one 2P&G-60A male to three 2P&G-20A female" "adapter" is illegal unless it contains three 20A OCPD s.
.

Have a look at 530.18 for the full story on the "honor code of overcurrent protection" in the land of fruits and nuts.

ST

 

[derekleffew]

NEC 2011 530.18(E) Plugging Boxes.

... Cables and cords smaller than 8 AWG shall be attached to the plugging box by means of a plug containing two cartridge fuses or a 2-pole circuit breaker. ... Plugging boxes shall not be permitted on ac systems.

1. Sounds like "plugging box" is a very specific term, applicable only to DC, and presumably for the stage plug. http://www.flickr.com/photos/mole-richardson/7156729659/lightbox/
2. Has anyone ever seen a "plug containing two cartridge fuses or a 2-pole circuit breaker" stage plug? A brief look at the Mole-Richardson site fails.
3. In general, how likely is it that the live entertainment (or TV/film) electrician will encounter DC power?
.

 

[MrsFooter]

3. In general, how likely is it that the live entertainment (or TV/film) electrician will encounter DC power?
.

On the ETCP test?

 

[STEVETERRY]

On the ETCP test?

Coming, surely.

Those of us on NEC Panel 15 have been reluctant to update Article 530 too much because there is a lot of Hollywood-specific stuff in there related to (now antiquated) practice.

But, it seems clear that we need to update!

ST