Line and Low Voltage Within A Lighting Pole

[flightline]

A job is being proposed whereby a number of special poles are going to be installed to support some AVI [automatic vehicle identification] readers. These will be located @ 16? above the pavement. There will also be 1 or 2, 1kW HID fixtures at the top, @40?. The AVI readers will require a communications cable as well as a power supply from a power limited supply. This could be a similar condition where someone wishes to install a CCTV camera on an existing light pole as well; the conditions would be similar. Normally the fixtures operate at 480 volts, but a 120-volt supply for the pole-mounted fixtures has been chosen. The transformation is within 50?, so voltage drop is not a concern.

What is a concern, however, is NEC 410.15 (b), in that there will be ?2- different potentials within the pole. Fishing in a flexible raceway from the base to the arms is one option. For clarification, I went to the 2002 NEC Handbook; they had this passage:


n 410.15(B) metal poles are permitted to be used as a raceway. If the pole is used as a raceway, the user is reminded to maintain the required separation between power wiring and any communications, signaling, and power-limited circuits that may also be installed within the pole.
For example, where a light pole supports a luminaire and a security camera, the security camera signaling and power-limited wiring may be installed within the pole cavity. Because the pole contains open circuit conductors (e.g., THW or XHHW conductors) to supply the luminaire already, the separation requirements can be fulfilled by enclosing the camera conductors within a flexible raceway and installing that raceway within the pole. Of course, the use of a cable or cord assembly for the lighting circuit conductors remains an optional choice for the user. The provisions of 410.15(B)(6) remind the user that the conductors are to be supported in accordance with 300.19, the same as a vertical raceway.
Section 410.15(B) is not intended to necessarily require the placement of a raceway for communications cables on the exterior of a lighting pole.

Would you take this to mean, as the handbook contends, that if we were to run to 120-volt lighting circuit via an approved cable, then no raceway separation would be required, as it would have already been achieved?

(resized photo for this post, compliments of Dave Nix aka websparky)

[ September 09, 2003, 08:33 PM: Message edited by: flightline ]

 

[don_resqcapt19]

Re: Line and Low Voltage Within A Lighting Pole

flightline,
First, can you resize the picture? It is way too big.
I think that you could use Exception #1 to 800.52(A)(2) for this application.
Don

 

[flightline]

Re: Line and Low Voltage Within A Lighting Pole

Don,

It's my first picture posted on a forum like this, and I'm embarassed as to how it has come out. If someone can tell me how to do that, I'll be only too happy to do so. I guess it's part of a learning curve. Sorry.

Thanks for the exception, I'll look into this in a few.

 

[Guest]

Re: Line and Low Voltage Within A Lighting Pole

You need an image editor to do it
after the fact. I use Microsoft
Photo Editor (MPE). MPE is a free
component of MS Office. You may
already have it.

[I am forcing carriage returns on
this post to prevent scrolling].

You open the image in MPE (or any
other photo editor) and click on
resize. Then do a "Save As" and give
the resized image a new name. That's
assuming you want to keep the
original "raw" image.

Generally I save pictures at no more
than 400 pixels wide if in the
Landscape orientation, or no more than
400 pixels tall if in the Portrait
orientation. That way it will fit on
one screen at almost any resolution.

Your camera may have come with an
Image Editor program.

Finally, when you take the picture you
can usually select a lower resolution.
My camera allows me to select:
</font>

• <font size="2" face="Verdana, Helvetica, sans-serif">Super Fine</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">Normal</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">Basic</font>

<font size="2" face="Verdana, Helvetica, sans-serif">That way I can take a smaller picture up front
if I am sure that I won't ever need the
bigger picture.

Some examples of image editors:
</font>

• <font size="2" face="Verdana, Helvetica, sans-serif">MPE</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">Photo Shop</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">Paint Shop Pro</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">...and so forth</font>

<font size="2" face="Verdana, Helvetica, sans-serif">

I have found that "Paint" is a lousy
way to resize an image. It destroys
the integrity of the photo when you
resize. It can work in a pinch if you
don't have an alternative. All Windows
OS's include MS Paint.

Another thing to look at is image quality.
Keeping the quality down will reduce the
image file size. This can be helpful if you
are emailing or posting pictures online--
especially if you or your recipient have
a dial-up Internet connection. 72 DPI is a
reasonable quality for email or online
publication. I find that resizing to 400 pixels
maximum width and/or height knocks any picture
down to a reasonable file size for online
enjoyment. Your image file size is 200K which
isn't huge for the size of the picture (meaning
your quality is low) but typically it's better to limit your file size to 50K (or less).

Once you resize your image you can repost it
to your image storage server so we can more
easily read this post (without scrolling).

../Wayne C.

PS: Are you HLS?

[ September 09, 2003, 03:11 PM: Message edited by: awwt ]

 

[iwire]

Re: Line and Low Voltage Within A Lighting Pole

The only way to resize it I know is to get the file into an image editing program.

Right now you image size is 1536 x 1024 pixels, a good size would be about 600 x 400 pixels at about 75 dpi give or take.

Bob

 

[iwire]

Re: Line and Low Voltage Within A Lighting Pole

Wayne, good info you beat me to it.

Originally posted by awwt:
I am forcing carriage returns on
this post to prevent scrolling.

How do you do this, as it is a lot easer to read your post then it is the others?

 

[Guest]

Re: Line and Low Voltage Within A Lighting Pole

Whenever you have to post
a long URL or post a H-U-G-E
image it can be helpful if
you limit the width of your
text.

To do the above paragraph I
hit the Enter key after post,
after H-U-G-E, after if, and
after your.

This forum allows the hard
carriage returns to persist.
Normally it does a "word wrap"
to contain your text within
the Window.

The problem arises when somebody
posts a really long URL or a huge
image as it increases the size of
your Window and then the text wraps
to that oversized Window.

My big monitor is gone for now, and
I'm using a small crummy monitor,
so I've learned a few tricks about
posting when there are
large images or extra long URL's in
a post.

Again, it's all in the Enter key.
I hit the enter key at every line
during this post, and twice to
creat paragraphs.

../Wayne

PS: Your post was short and sweet. My big
monitor will be here soon enough. Then I
will complain that the images are too small
no matter how big they are

[ September 09, 2003, 03:19 PM: Message edited by: awwt ]

 

[websparky]

Re: Line and Low Voltage Within A Lighting Pole

2002 NEC 830.58
(A) Separation of Conductors.
(2) Other Applications. Network-powered broadband communications cable shall be separated at least 50 mm (2 in.) from conductors of any electric light, power, Class 1, and non?power-limited fire alarm circuits.
Exception No. 1: Where either (1) all of the conductors of electric light, power, Class 1, and non?power-limited fire alarm circuits are in a raceway, or in metal-sheathed, metal-clad, nonmetallic-sheathed, Type AC, or Type UF cables, or (2) all of the network-powered broadband communications cables are encased in raceway.

I think this is the correct code reference for your situation.

 

[Guest]

Re: Line and Low Voltage Within A Lighting Pole

Don't the LV and HV have to be in separate raceways? A light pole even if it's a raceway is a common raceway. Or, am I not reading this right?

../Wayne C.

 

[flightline]

Re: Line and Low Voltage Within A Lighting Pole

Thank yo so much Dave, [aka websparky]

 

[websparky]

Re: Line and Low Voltage Within A Lighting Pole

or in metal-sheathed, metal-clad, nonmetallic-sheathed, Type AC, or Type UF cables, or (2) all of the network-powered broadband communications cables are encased in raceway.

Hi Wayne,

It seems to say that as long as one of the wiring methods is in a raceway or one of the above execptions, that it would be acceptable. If so, this would also apply when they are installed inside of a lighting pole.

 

[websparky]

Re: Line and Low Voltage Within A Lighting Pole

flightline,

You are welcome!

I think this is the type of low voltage wiring method that applies to your question.

 

[Guest]

Re: Line and Low Voltage Within A Lighting Pole

Originally posted by websparky:

or in metal-sheathed, metal-clad, nonmetallic-sheathed, Type AC, or Type UF cables, or (2) all of the network-powered broadband communications cables are encased in raceway.

Hi Wayne,

It seems to say that as long as one of the wiring methods is in a raceway or one of the above execptions, that it would be acceptable. If so, this would also apply when they are installed inside of a lighting pole.

I can see that. A raceway within the raceway. The LV uses the pole as its raceway and the HV uses its armor. However, I guess I misread the OP and thought the proposal was to use the light pole as the raceway for both. In that case it would be mixed media in one raceway. Maybe the OP can clarify.

../Wayne
OP=Original Poster or Original Post.

 

[flightline]

Re: Line and Low Voltage Within A Lighting Pole

well, that's kinda' what I'm asking. Let me give you a for instance, and to some extent my confusion. lets say you ran a uf, [ or if it were recognized for use in conduit] like a type TC cable, 12/3, for the 120 volt lighting power. This would be a jacketed, self contained cable so to speak, and then you would have the 2 cables that go to the AVI reader. That's what I take from the bolded verbiage in the handbook's comment, BTW, the raceways that would contain the 120 volt lighting power are large enough so fill would not be violated.

So I guess my question could be re-phrased, " if all conductors were contained in their own approved cable assemblies, would that then be a code compliant installation.

As I originally mentioned, we could always install raceways within the pole, but if the "all cables" solution meets code, it would just be that much cleaner for us.

 

[Guest]

Re: Line and Low Voltage Within A Lighting Pole

Kudos on resizing your image.

I would still suggest that you limit your height and width to 400 pixels. This drives the file size down, and it allows the image to be viewed on one screen at almost any resolution. Right now your picture is 700 pixels high so even at 800x600 resolution it spills off a page. Many people use higher resolutions (higher than 800x600), so it's not an issue. 800x600 is still the most popular, and some people (not a lot) are still at 640x480 monitor resolution. Again, if your pictures never exceed 400 pixels in height or width then the picture can be easily viewed on any screen. The reason I say 400 max on height is so there is still some monitor real estate left for the computer toolbar(s) and also the web browser toolbar(s).

I hope you have gotten the answer to your original question. Now that you know how to resize a picture, experiment with limiting them to 400 pixels.

../Wayne C.

[ September 10, 2003, 11:27 AM: Message edited by: awwt ]