Traffic Signal Troubleshooting - Dual Indication Faults

You've been called to a flashing traffic signal. You open up the cabinet. There it is....that black box thingy that states 'Dual Indication'. What does that mean? You'll see that exact problem today when I was troubleshooting that exact fault!

[@somethingelsehere8089]

Thanks, enjoyed the video. Nice to see a little behind how these work.

[@streetsmartstraffic]

Thanks for the kind comment! Much appreciated

[@kens.3729]

Thanks for your Persistence! Keep up the Strong 💪 Efforts. 👍🙏

[@streetsmartstraffic]

Thanks! Trying to! lol

[@MikeM-cz5ln]

I would open up the other poles hand hole and make sure there aren't more of those goofy terminal blocks installed.

[@streetsmartstraffic]

Good call! I haven't done this yet. I isolated the issue to this corner as this is the one that keeps causing it to go into flash. But who knows what other future issues could be lurking! 😬

[@jeromewelch7409]

Awesome video extremely interesting content! Are the traffic lights AC voltage or DC voltage? I'm assuming at the location of the control cabinet it would be impossible to have dual indication through what looks like an output modules 8R 8G terminals; one would think the logic would be an 'OR' operation, green or red; as would be, with coil, driven, relay logic? in this configuration, it would be impossible to have both indications on unless it was backfeeding from the field wiring? as it doesn't appear there any isolation. Relays ? All the red wires go to one terminal which I assume is all the lights you want red in the two cardinal directions it serves? It's interesting to me that your output module doesn't slave the coil of a relays? for the cardinal directions involved! Designing the circuit in this way, would absolutely isolate any possibility of having dual indications…. Feedback I'd love to understand more about how this stuff works thanks again for the video, Agape, Brother

[@streetsmartstraffic]

These lights are 120V AC. You are exactly right about your statement. In this case, it was a backfeed. Yes, all red wires for a certain direction are fed to the 'R' terminal for that direction. Same for the 'Y' (yellow), and'G' (green). A load switch takes the output from the controller (logic) and converts to the 120V AC which is what the indications in the street use. I post weekly videos on traffic signals and also have an online membership that i teach all of this stuff. Anyways, thanks for the kind comments!

[@smgutz]

having all the splices in the hand hole seems pretty wild to me. they're in an SVT for us

[@streetsmartstraffic]

We don't usually have splices in handholes. Too much can go wrong. But this was done before my time...I'm not sure why this particular cable was spliced to begin with. For now, its working though on the spare wire we had available. If that didn't work, we would have definitely pulled in a new cable. Thanks for your input!

[@SOU6900]

What voltage do the heads use anyway?

[@streetsmartstraffic]

These are 120VAC. There are low voltage traffic signal systems out there that use 48V but you'll mostly find 120VAC

[@anthonyamor4411]

I am an IBEW 353 electrician and have been working in traffic services for the city of Toronto for about 20 years, and have seen some pretty shady work, but WTF, who uses a terminal block inside a pvc "C" fitting and then jams that abomination inside a traffic pole, what could possibly go wrong.

[@streetsmartstraffic]

LOL! EXACTLY! Glad we're in agreement...

[@kc0eks]

Please get a pop filter. Mouth noises are unpleasant. Love the content though

[@streetsmartstraffic]

Sorry about that. I'm piecing this thing together with a simple Iphone & poor man's video editor!

[@user-ln7of9gs4s]

I don’t notice. Just enjoy the video. I feel you’re being a little over critical.