Site Poles With 480V and Cameras

[iwire]

I am doing a site lighting job that the prints show two poles with 480 volt heads and security cameras.

These poles have separate underground raceways that bring

1)480 Volt fixture power

2)Unknown camera power

3)Unknown conductor for Camera signal

The prints show these kept separate into the pole base and a print note tells me to run 2 3/4" EMTs inside the pole to keep the systems separate, all good so far.

The inspector when looking at the underground wanted to know about all the raceways and I explained it to him.

He said he would let me do this if I could explain how I would deal with this at the top of the pole, how will I get from the EMTs to the camera, the 480 will be run loose in the pole.

The inspector suggested pull ells but that would require a hand hole cut in at the top to get to these.

Personally I would rather see separate poles but that is not an option.

Anyone have any ideas, or experience with this?

[ April 26, 2003, 09:00 AM: Message edited by: iwire ]

 

[bennie]

Re: Site Poles With 480V and Cameras

Bob: Determine what wiring is needed for the video cameras.

I have two at my house, they are powered with 24 volts, by a 3 conductor #18 flexible cable. This cable is shielded.

The proximity between the power and video cable should not cause any coupling of signals.

Does the shielding constitute physical separation?
I don't know. I think it should be considered.

 

[don_resqcapt19]

Re: Site Poles With 480V and Cameras

Bob,
I have seen a combination cable used for this application on the tall poles that have a light ring lowering system. I don't really see how the combination cable complies with the code rules, but have seen it used without problems. The one that I know of has 3? 480, 120 volt camera heater power, coax for the vedio signal and a twisted pair for the pan and tilt camera control. This is on a 100' pole so the cable is about 100' long.
Don

 

[iwire]

Re: Site Poles With 480V and Cameras

The camera power in this case may be 120 AC the existing ones on the building have some sort of power supply at the camera that converts the voltage down. Which is good as the run length is 1500 to 2000 feet one way and at 24 volts I would see some pretty serious voltage drop.

The existing ones have coax, but the GC claims the new ones will have a Fiber signal cable.

I have nothing to do with any of the camera installation, I just own a code compliant raceway for the security contractor.

 

[gregory]

Re: Site Poles With 480V and Cameras

How about taking the conduit out the top of the pole into a 1/2 or 3/4 service head. Then go to camera, This will seperate systems

 

[iwire]

Re: Site Poles With 480V and Cameras

Don, I did not see your reply before I posted, but changing the cable is out of the scope of my contract.

But it could happen if I can not satisfy the inspector and give this problem to the EE.

Gregory, That is something I had not thought of and would be workable with some modification to the site pole "cap" if I can sell it to the customer I think this could satisfy the inspector who is a nice guy and I think on the ball for catching this.

 

[bennie]

Re: Site Poles With 480V and Cameras

Bob: Is this 480/277 power to the poles? Do the specs require ground rods at each pole?

 

[iwire]

Re: Site Poles With 480V and Cameras

Bennie, The fixtures are straight 480, no neutral was brought out from the building.

No, there are no specs for ground rods at the pole base, which considering the elaborate ground ring and bonding I am doing for the addition that these lights serve surprises me.

The inspector also asked about the grounding conductor size, the prints show 2 8 AWG for power and 10 AWG for grounding which is a violation (2002 NEC) but even with out the code 10 AWG seemed small for the length.

 

[frenchelectrican]

Re: Site Poles With 480V and Cameras

hi bob :

i am suprised what the spec say no ground rods. all the years i work with area lighting system i know the rules better than that and i alway put a ground rod for each one and the grounding wire or bonding wire depend which way you want to say it i use #6 . i did work on one fixure that i work on it not too long ago i have to replace it the oringal wire was #10 and i say that is way too small for even for lighting protection so i suggusted my clinet to replace and put new wires and it work alot better now .
and second question to ask you bob what size light it willbe ??? ethier 400 watts or 1,000 watts mh if i am right ???


if i am wrong just correct me

merci marc

 

[iwire]

Re: Site Poles With 480V and Cameras

Marc most of the jobs we do the specs show ground rods at each pole, sometimes 6 AWG up to the pole itself or other times cad weld to the J-bolts or rebar's, I am surprised that this job does not have them.

As for the fixtures they are 250 MH on 25 foot poles, and 120 feet between them, they are defiantly going cheap on the site lights, but the work in the addition will make up for that, pharmaceutical research and manufacturing faculty.

 

[frenchelectrican]

Re: Site Poles With 480V and Cameras

wow bob i can see what you mean about the site lighting 250 watts mh with 25 ft poles with 120 foot spacing that really streching but i can understand that. the company is expansion and i belive they will add some kind of wall pack fixure to make the diffrence ..


i do agree with you what you useing the grounding system i do the same way too i use #6 and few other place ground rod it and few place cadweld ( majorty of time groundrod it and run #6 together to improve the grounding system)

and i did check my paper chart and i have lighting fixure layout chart with me and for that much spacing better off use 400 watts or 320 pulse start mh (kinda new around here and i love it it have same punch as old 400 style have )but i going to wait and see how you come out with it . and many luck with it. i hope it can be sucessfull with it . and i was thinking what gregory was saying about use the top of pole for the camera that is good idea with it. but one thing i thought about it is the conducts inside the steel post i wondering what if use the liquidtite fexiconduct will work but bear in the mind about weight near the top can affect the fitting to hold it. i try to work a idea how it can work inside of it. if you have a good idea just pass the note here


thanks again marc

 

[sheryf]

Re: Site Poles With 480V and Cameras

You need to get the specs from the camera to see if there are 1/2" NPT K.O. 's for connection. I just finished work on an INT'L airport parking lot with cameras on light pulls out the gazzoo. I fed each pole base with a 3/4" conduit for camera and a 3/4" conduit for 120/277V (camera/light power). Once I entered the pole with my stub up, the pole is a listed raceway. I utilized fiber optic for most of the cameras which could care less about the presence of line voltage. The 120v power was connected to the camera by utilizing black non-metalic flex (this instalation looks much cleaner that a weather head) The fiber can run inside the carflex without any interferance. The 277V hot and Neutral connected to the pole lights via manufactured connection points and thus remained unexposed. The finished product was neat, inspected by the local inspector as well as FAA security personnel. Utilizing the 3/4" emt inside the pole is nothing other than added tamperproof protection, especially if you are already planning on running your line voltage conductors in the same pipe to each pole. If you are using coax or CAT 5e, It must be shielded cable. You can place it in the conduit for seperation but keep in mind once you reach the end and connect it to the camera in will be approximately 1" apart at the connection point. My camera specs showed no requirement for seperation had I used COAX.
On the grounding issue. Always pull a full size ground that is increased proportionate to the voltage drop calc for the ungrounded conductor. Most light poles are set on a concrete footing, so I always drop 20' of #4 bare into the footing will the rebar during my stub up process. UFER grounds are the way to go now a days in my opinion. My inspector really likes it when I do a parking lot job because I don't cut any corners on grounding issue. Sorry to hear about the 250MH choice. Don't we all know how dim that will be. Maybe you can sell them up in the future.
Good Luck