Light Post and Security Cameras

Sounds rather far-fetched to me. Someone struggling for excuses for faulty gear, maybe?

Before I'd swallow that (it is possible), I'd like more evidence and explanation. If I didn't feel capable of understanding by myself, I'd have a good plant electrician or engineer with me at the explanation.

The subcontractor should be able to show which component(s) is failing, and make some good guesses as to why, which your electrician / engineer should be able to judge.

Is the subcontractor blaming it on voltage surges? (During lightning storms?) Or what? Does the camera use 220 volt power directly, or does it need 110? If 110, exactly where is that connected and is one side hot and the other side grounded? I'm sure more appropriate questions can be asked when understanding exactly the problem the subcontractor is claiming.

could it be that when the starter on the lights fires up the interference is taking out the equipment.

a cure would be to fit inline suppression to the supply to the cameras

most ccd cameras are sensitive to interference

http://www.google.co.uk/search?q=mains+borne+interferrence+suppresion&sourceid=ie7&rls=com.microsoft:en-US&ie=utf8&oe=utf8&rlz=1I7GPCK_enGB411&redir_esc=&ei=Z_0VTbHAOobLhAeV6vi3Dg

Happy christmas

I felt that you may have hit the nail on the head with your post, therefore a GA from me.

This sounds far fetched to me. I think the critical question is did this installer know that the cameras would be installed on the lights before they accepted the project? If they did know then their warranty should cover all repairs regardless of light ballasts switching or anything else. Regardless of who has the business responsibility here, putting back units that will fail again is a demonstration of futility.

To attempt any failure analysis one must know how and when the cameras are failing. If they tend to fail after a lamps start up cycle then there maybe merit to the installer's claim. Since these are security cameras I'd expect some form of a log on when failures are detected.

A common failure point in electronics is the breakdown of electrolytic capacitors. Often people forget that the Arrhenius chemical reaction equation means that the expected lifetime of a capacitor halves for every 10°C rise. So there may not be an electrical problem but a heat problem on top of your lights.

As mentioned earlier without knowing what goes bad with the camera system it is impossible to give a reasonable answer. Given my past experiences with independent contractors and the persons they sub hire I can attest to them usually installing the lowest cost components to maximize their profit and then coming up with explanations to pass the faults of having used cheap equipment on to someone else.

Being the lights and their power system where there first I would say the camera guys at fault for installing a system that was not compatible or properly designed to work with the existing lighting systems and related environmental issues.

SInce the cameras are on 24/7, they need their own AC source, and they should also have their own ground. Best is the ones fed by DC up the coax, as they are isolated.

Running them from the lamp 220V might cause gradual failure from the high ballast startup current.

Find how they fail, and find the common mode.

Assuming the lights are probably sodium vapor or mercury vapor lamps, the means by which the lamps are ignited is for the starter to generate a high voltage spike in order to fire the plasma arc inside the lamps (which subsequently lowers the impedance of the lamp so that the mains voltage is able to maintain the plasma).

It could be transients reflected onto the line or even radiated EMI due to the current spike. Filters will help with conducted line noise but if it is radiated you will have to shield or increase the distance from the lamps.

Yep that sounds about right - you get some hefty spikes from discharge lamp ballasts. And if the supply runs are common these would end up stressing the cameras voltage regulators which are commonly good for about 40 V.

I'd suggest some ferrite on the leads and a ~30V x 5W zener with an ohm or three in series, at the camera power supply PCB.

The Same thing happened to me at Round Hill Country Club Alamo,CA. It wentbackand forth for almost a year. The camara guy ended up with new poles and I ended up replacing all the light fixtures. Than gussed what happened after the MH lamps burned in.

You wrote:..."Than guessed what happened after the MH lamps burned in."

It burned again....

Thanks to all those who took the time to answer. I do have now a more or less an idea of what I am about to do.

Thanks again to all of you guys.

Wangito.

I suggest to use IP camera with fiber to ethernet media convertor. Fiber would not be disturbed by electricity 110 or 220. Can be little expensive but solved the problem.

i think the op`s problem isn't the picture transmission but the camera itself failing caused by spikes in the power supply when the starter circuit fires up to ignite the lamp

Agreed!

your problem can be easily solved. I suggest you, to have an wireless Ip camera from http://www.247securitycameras.com/