LED sign doing weird stuff

[visual800]

We helped install a set of LED channel letters. Letters were 7' tall spelling JACKSON with a logo. Logo is 12' tall circle. Damn thing was massive, all attached directly to concrete wall. The electrical was over 20' long behind the wall. Power supplies all lined up and covered with aluminum "caps" We installed this about 7 months ago with photocell. All was working fine this whole time. The letters are UL and were made by sign fabricators in Birmingham and shipped to the other sign guy.

He sent me a video yesterday titled WTF! someone had emailed him from the facility. In all my years I had never seen anything like this. The lighting would run in streaks across the whole lettering almost like chaser lights. Since this thing has about 7 power supplies it had to be the power in the main Jbox that was run by the facility. We are going there Monday and put a multimeter on the Jbox for the main power source feeding the whole sign.

Has anyone ever seen LEDs do something like this is? It is the most bizarre thing I have ever seen. Im thinking main power source is jacked up that was installed by local co-op. The video is not worth posting as it is on cell and very hard to see unless you know what you are looking at

 

[Rocco G]

I'm just throwing out random thoughts. Not having seen the job and specs I can only guess. Maybe something I or someone else will mention might put you on the right track. Best of luck with this one!


When you say that the power supplies were covered with aluminum "caps" do you mean some type of pan to hide them? Are these caps grounded? I'd bet that it's an artifact from the power supplies being all closely grouped together thought that's a wild guess. Perhaps the ground that was supplied with the circuit is faulty? Perhaps they added other things to the sign circuit afterwards?

One other thing comes to mind. A local theater asked me to replace their 11 watt std bulbs with LED bulbs. When I went to one local electrical supplier to price the LED bulbs, the guy at the counter cautioned me about grouping so many LED bulbs in close proximity. Apparently they had issues with people replacing all of their bulbs with LED items and then the first/last in a series would flicker on/off. He didn't know exactly why, but it probably had to do with the circuitry in the bulbs. I'm not saying that this is the case with your sign, but with that many modules grouped together you might get some strange electrical effects.

What size wire was used to connect the LED's to the PS's? With that many mods and a 20' run I'd think that 14 GA is necessary even if the LED mfr states that 16 or 18 is adequate.

I have seen whole letter set flicker but that's when they were set up with too many modules for the number of power supplies. I never saw then chase though.

Again, these are all random thoughts. I'd love to know what the culprit ends up being. We install a lot of LED letters for out of town companies and if it happens once, it will happen again.

 

[Westcoast Sign Guy]

20' run?

What guage for the secondary, and what did you load each 60watt PS to? Did you account for voltage loss as well? Take your meter and see what your voltage is for each line going funny?

Are the LEDs constant voltage or constant current?

How many LEDs are their per string? How were the LED string connected? Did you branch out the strings a lot? Did you you connect the secondary coming from the PS to the middle of a string or at the end?

 

[visual800]

Let me explain the 20'. Behind the wall where we fed all leads was 20' long. Where fist lead was dropped all the way to the other. All power supplies were mounted in a straight line. All electrical was run in a nice line with nylon hold downs. We always do clean work like this and made an aluminum "raceway" to cover it all up. The raceway is flanged on edges that secure to wall and rises 8" over power supplies and wiring. Ill also add this, the room all the electrical comes into is where all the elevator motors are and they keep it at about 45 or 50 degrees, cold as hell in there.

we connect all with 18g stranded with 2 way compressions. We did split this whole sign up by running it off of two J boxes split off the main J box ( might be overkill but felt necessary). All worked and was checked before we capped off all electrical with raceway.

westcoast as I mnetioned this was built by sign fabricators and I do not know how many LEDs are running off power supplies nor do I know of constant current or voltage. This company has always matchedthe apropriate feet of LEDs to the power supplies.

we are going to check all power supplies for voltage and statrt with main J box. Ill be willing to bet they tapped onto our min line ansd added something.

 

[Westcoast Sign Guy]

I've seen a ton of jobs built by fabricators that were poorly put together, small to large nationals. In either case a lot of what I put out can make a huge difference even in conjunction, and won't happen rioght off the bat but take affect over time. This sign requires a lot to have 7' letters and a 12' logo. Only 7 power supplies for this you say? How many rows of LEDs does this have? I just put up a set of 15" channel letters single stroke 19 letters and that was 3 power supplies, .72 & .50 watt modules.

In either case, I guess to eliminate yourself from the issue you need to verify you have clean power, and most paramount, dedicated power....not shared. Did they the sign fabricators account for the 20'+ feet for their loading? Lots of companies like to stretch their dollars by almost max loading whether it's Neon or LED looking at the sign on paper and not based in the field in which it was/will be installed

 

[Rocco G]

"we are going to check all power supplies for voltage and start with main J box. Ill be willing to bet they tapped onto our min line and added something."

I'll vote for this after reading your description. It will be a case of "...but the sign is only drawing a few amps so we didn't think it would hurt to add something..."

And I would love to see that video. Something is gnawing at the back of my head telling me it's the power supplies themselves because these are what powers the modules. Are the individual letters going on/off as a whole or is it sections within the letters?

 

[MikePro]

you should tell them that the "Starlight-effect" usually costs extra, but you'll let them have it for no extra charge :ROFLMAO:

+1 most definitely a power-supply/installation issue. can't tell for sure without seeing/testing first-hand, but I would have their electrician start with a multimeter... there's nothing you can do on your-end aside from directing them to reading the spec's and making sure your sign was installed properly on their-end.

 

[J Hill Designs]

if its all daisy-chained together then its probably overloaded. if each PSU is only powering certain sections then its probably a primary power issue.

 

[visual800]

Well we found the issue. Main power was 120. Power coming from photocell was all over the place. Went outside and looked at photocell it was half full of water! We used weatherproof box and siliconed hell out of it BUT noticed someone had pressure washed builded cause thewrote their name on a wall on the roof with washer. They blew silicone off top of box and it has ben leaking inside.

situation handled! Never had I experienced this before

 

[visual800]

Busted

 

[Signsforwhile]

Damn it I was gonna say photocell!!!

 

[letterman7]

Send the power washing company a repair bill..

 

[Rocco G]

I'm glad it was a simple fix. Troubleshooting weird elec issues can be tough.

I'd try to get something in writing from the customer about the power washing company being at fault (yeah, I won't hold my breath either) and that if the power supplies fail too early it won't be under warranty. If the PS's were going nuts from the bad input voltage, who knows what damage might be done to their internal circuitry. I'll bet that you are back again soon.

 

[visual800]

I asked maintenance how long sign was doing that before they sent video and main guy said they shut breaker of immediately! So hopefully no damage was done. Thank for all responses.