Red Light Camera

[RichB]

Here is the situation:

City wants to put up cameras using their service and tie into our signal system for red and amber inputs.

This would give two seperate sources of 120VAC in the camera control cans--their power supply and our 120VAC to the signal heads.

Ok now trhe questions and what I have found:
1. Is this a violation with seperate sources--300.3(C)(1) would seem to say that it is not as long as the wiring insulation is all rated for 600VAC (I seem to remember that it is a violation or was I doing it wrong all these years by seperating)
A. Also after discussing this with another inspector it also seems that the conductors to the signal heads would now be considered control and signaling not power also making this a legal installation.

Thanks in advance!

RichB

 

[SG-1]

I will only suggest that a large warning sign be posted that states: WARNING this box is energized by two seperate 120V sources.

 

[RichB]

That was one of my mark ups on the plans--bundle the conductors and label at all accessible points and placard the cans

 

[zbang]

Also after discussing this with another inspector it also seems that the conductors to the signal heads would now be considered control and signaling not power also making this a legal installation.

Since the leads' primary purpose is to power the lights, I'm not sure how monitoring them would turn them into control leads any more than connecting a pilot light would. OTOH, unless the camera control inputs are isolated (relay, opto, or transformer), I'd be rather wary of interconnecting the systems. Too easy for a mis-wired camera system to take out the traffic signal, esp if the two services are fed off different transformers.

I assume that taking outputs directly from the traffic controller is not an option.

 

[RichB]

SMACK!!!!

zbang--That is the sound of my hands and forehead meeting-several times-:roll:-Yes they are using the same POCO xfomer and yes there is an opto isolater in the can for the inputs--I got hung up on the details and missed the obvious.

Thanks!

Rich