Being Persistent when Troubleshooting Traffic Signals
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- čas přidán 3. 06. 2024
- When it comes to troubleshooting traffic signals, sometimes it just doesn't go easy. That's when you need to be persistent. Don't give up! Keep figuring out where the problem lies by isolating the issue. You'll see in this video, I didn't do a very good job of that!
You can get tools like the ones I'm using in the video here:
Fluke Meter 117: amzn.to/3K9ir1M
Note: These are amazon affiliate links that helps this channel at no cost to you - Věda a technologie
Carry a spare circuit breaker in your toolbox. Feed each one of the yellow feed wires through the breaker one at a time until you find the shorted wire. Or just touch each yellow field wire to AC hot until you see a big spark - short circuit. Then run the intersection with the shorted wire not connected. Observe the lights to see which yellow light is out. Since you have 4 wires under each terminal it appears you have home run cables to each traffic light - a good situation.
THanks for that info Mike! I haven't tried the circuit breaker route...but that makes total sense. and yes, homeruns would be easy to do that with
Thanks for sharing the troubleshooting process unedited! Great vid!
You're welcome! and thanks for commenting!
More like this! Awesome video!
I noticed the green "protected right" on the side street was coming on when your problematic yellow was hot. Interested to see what they find in the field.
Great video, look forward to more raw like this!
I'm not sure if you want to watch me fumbling around like I did in this video lol...Thanks for the comment though!
Love your vids and I also just noticed that you use the same work gloves that I do! rugged wears are nice gloves
Hey thanks alot! I like the gloves alot (bought a 3 pack). Had others in the past and they were too thick to do any of the tedious work. These work great. Thanks for commenting!
I would be willing to bet the 3-4V of "backfeed" you were getting was just AC coupling from the flashing red indicators (and the different peak voltages was probably due to the relative length of the runs...i.e., a longer run is more length for the voltage to couple across). The lone yellow line that was not slinging stray voltage around was shorted somewhere, so the capacitive coupling was getting dumped to ground somewhere along the run (or in the head) rather than making it back to the cabinet. The TRIACs in the load switches *should* be able to handle backfeed, as long as they're all running off the same mains phase (i.e., it isn't a 230V cabinet), but they'll let the genie out on a dead short.
Also, if you set the manual range on those Fluke DMMs to ~100V, the display response is a lot quicker to transients like a flashing signal, since it isn't trying to autorange across its 600V limits.
Came here to say exactly this. Minus the Fluke ranging thing, that's good to know. Some of Fluke's industrial meters also have a special low impedance mode to help with this misreading too.
I also was going to say the same thing - switching over to Lo-Z (low impedance) on my Fluke gets the float to go away from capacitive coupling. Even a couple of their field meters like the 117 have Lo-Z mode now.
When I saw that my guess was that one head had a yellow shorted to ground, thus no AC phantom coupling from the red run in that conduit. Shorted to ground would certainly stand a good chance of blowing the triac in the driver.
The short could be anywhere, but I've seen incandescent lamps blow in a way that resulted in shorting the support wires inside the lamp, presenting a dead short to the dimmer (or load switch in this case). Experience with incandescent lamps tells me the first thing I'd check is the lamp in that head, and only if it isn't the problem try to track down some other problem.
Thanks for your thorough comment! See, this is another reason I started this channel! To let others (smarter than me) to share great information like you just did. Much appreciated!
@@the.og.lylebob THanks for the commenting and the information! Much appreciated!
A high resistance Neutral connection can cause a small back feed voltage.
I believe it was found that there was a Neutral issue. Thanks for your input Steve!
I'm fascinated by how archaic all this is. This is so similar to telephone central office stuff from the 30s to 70s.
Dave-sometimes I wonder if some of these cabinets were built during those times... LOL
Probably for the same reason you don't see a Raspberry Pi as the avionics controller for an airliner or a logic controller for an elevator -- reliability. Traffic signals need to be 100% fault-tolerant, and fail to a known-safe state. It's difficult to make that claim about many modern software-controlled electronics, and going through the development and certification process for new hardware/software is an extremely time-consuming and expensive process, so not something companies want to do very often.
@@ereisch I agree with the reliability aspect. I'm referring more to the mechanical aspects. Screw terminals are incredibly time consuming for wire termination. That's why the phone companies left that behind decades ago.
I wonder if new traffic signal builds still use screw terminals.
@@ereisch Well said. I hear the comment sometimes that says: "I could run an intersection with a raspberry pi or an arduino!" While you COULD probably run an intersection, there's alot of standards and inside testing of the equipment to hold up against temperature, dust, etc. There's in house testing (such as heat chambers) that the equipment goes thru for example. And yes, better have deep pockets to enter a new product into this industry...
Thing i wonder is why the person before put a Green LED module in the cabinet, Probably an old broken one?
Is that an LED module, or a glass lens?
THis was actually a green lense to a LED module. Yeah, I'm not sure why it was in there either...lol
Why the F does the only car at the lights (usually me) have a red and the other sides with no cars the green?
You? I thought that was only me! LOL Many times, I'll tell me wife while we're sitting at a red light--gimme a sec...I'll take care of this 🤣
A Raspberry Pi can run a lot more than a couple lights.
You know, I always felt I could run one with an arduino or basic stamp (or raspberry pi). But there are alot of checks and balances that are done behind the scenes. And it requires rigourous testing (including a heat chamber) for products to go thru AND the the approval process...
But....LOL
Thanks for your comment