# Building wide LED a19 flicker



## CoolWill (Jan 5, 2019)

Don't rule out a utility problem. Some times, you'll chase a ghost that isn't even in your part of the system.


----------



## jelhill (Nov 11, 2018)

CoolWill said:


> Don't rule out a *utility problem*. Some times, you'll chase a ghost that isn't even in your part of the system.



Yes, @CoolWill has a good point. I was called to a Church annex where the smart TV's were getting fried, LED's flickering, and they were having sound system problems. After a lot of hair pulling it turned out to be intermittent surges from the POCO. Their excuse was that an industrial plant close by was causing it.


----------



## brian john (Mar 11, 2007)

You could hire someone with a Line Disturbance Analyzer (and the knowledge to interpret the results)and recreate the no flicker and flicker issue and see what is captured at the main service, panel and point of use.


----------



## just the cowboy (Sep 4, 2013)

bjt809 said:


> We have a few other types of fixtures with built in LEDs and *others with a different brand of LED a19 that Do Not flicker once the the others start*.
> 
> Any input?


 
What happens when you put the other brand bulb in the areas that are flickering?? Do not rule out bad bulbs,


----------



## jelhill (Nov 11, 2018)

just the cowboy said:


> What happens when you put the other brand bulb in the areas that are flickering?? Do not rule out bad bulbs,



Great point... I have seen single LED 4' double-ended tube lamps flicker... I just assumed the tubes had drivers that crapped out. New tubes fixed the problem.


----------



## bjt809 (Jan 25, 2019)

jelhill said:


> just the cowboy said:
> 
> 
> > What happens when you put the other brand bulb in the areas that are flickering?? Do not rule out bad bulbs,
> ...


We ended up swapping out 2/3 the lamps with a different brand that have 1w higher. Then off a seperate panel in the building used a sample of the flickering lamps and new lamps, bases, and toggle switch and still had the issues. We are convinced it's a bad batch of LEDs and shocked that it's majority of a 300+ lamp order.


----------



## bjt809 (Jan 25, 2019)

jelhill said:


> CoolWill said:
> 
> 
> > Don't rule out a *utility problem*. Some times, you'll chase a ghost that isn't even in your part of the system.
> ...


Unlikely. 600 Voltage was consistent in the splitter and xfmr. 208/120 voltage at xfmr, panel, switches/dimmers, and fixtures were also consistent. 

Ended up just replacing flicker lamps.


----------



## bjt809 (Jan 25, 2019)

brian john said:


> You could hire someone with a Line Disturbance Analyzer (and the knowledge to interpret the results)and recreate the no flicker and flicker issue and see what is captured at the main service, panel and point of use.


Would be interesting to see results. We did however ended up just replacing all the flickering lamps. It's just very odd to see the same frequency of flicker over 100 bulbs in different fixtures and seperate circuits.


----------



## CoolWill (Jan 5, 2019)

There's some kind of resonant voodoo going on with the one brand. The particular dynamics of their power supply capacitance is causing some kind of disturbance that's reflected around the system. A harmonic ghost that I don't understand the math that describes it.


----------



## telsa (May 22, 2015)

No end of these issues would be OBVIOUS if you placed an oscilloscope across the lines.

1) No end are due to driver engineering.

2) No end are due to undersized neutrals.

%%%%%%%%%%

No end of seasoned electricians are fooled because they were raised, trained and seasoned in the incandescent era.

STOP thinking like that.

1st lesson: reflected energy travels up from the ground on the neutral -- at the frequencies involved.

2nd lesson: you can't use the simplistic models you've learned as an apprentice. Solid state electronics uses frequencies you can scarcely imagine. You have left the world of Edison.

&&&&&&&&&&

I've been round and round with this: but at the crazy frequencies used by electronics you get BACK WAVE EMF from up out of the neutral.

This reality is beyond the conception of practically every electrician.

Bounce-back is just something that -- they assume -- is impossible.

At the frequencies involved, the Earth operates as a plate of a capacitor.

Get it?

This bounce-back energy has to be bled off... when it becomes a performance issue.

( Inductors, hint, hint... )

Most of the time, it's NOT an issue. Folks don't even realize that something's up.

Why? It's a second or third order effect that is NEVER brought up during their apprenticeship.

And then, like magic, later on, "What's going on?"

DON'T look to your hots. Look to your drivers, look to your neutrals.

The last place to look is the Poco. 

If they were that screwed up... the phones would never stop ringing.

BTW, Red Chinese production standards are terrible. 

So having an entire load of cr## is a common experience.


----------



## bjt809 (Jan 25, 2019)

telsa said:


> No end of these issues would be OBVIOUS if you placed an oscilloscope across the lines.
> 
> 1) No end are due to driver engineering.
> 
> ...


Great Insight. I had thought of the harmonics theories and bringing a larger circuit neutral on one of the sets.

The largest load of LEDs is around 10a (160bulbs). I originally ran a set off RD, BK,BL, Wh #12 t90 thru EMT, and load is less that 50ft from panel which I thought would never be an issue


----------



## The_Modifier (Oct 24, 2009)

Are there any MLV drivers on those LED's? We've run into that before and that was the solve.


----------



## The_Modifier (Oct 24, 2009)

The_Modifier said:


> Are there any MLV drivers on those LED's? We've run into that before and that was the solve. Also if the switch is controlling the MLV driver and isn't rated for it, that will happen as well.


:biggrin:


----------



## Wiresmith (Feb 9, 2013)

telsa said:


> No end of these issues would be OBVIOUS if you placed an oscilloscope across the lines.
> 
> 1) No end are due to driver engineering.
> 
> ...




do you happen to have any good literature or articles you could point us to on this subject? i'm finding some but do you happen to have any ones you recommend?
thanks








http://pe.org.pl/articles/2012/11a/61.pdf


----------



## goldengadgets (Apr 8, 2019)

I'm a LED Lighting distributor and the level of expertise on diagnosing this problem is incredible.

From experience with dealing with a variety of vintage filament style LED bulb manufacturers, I have noticed a significant variation in the quality of the bulbs vs standard LED bulbs. 

To achieve that vintage transparent glass + filament style LED bulb, manufacturers minimize the drivers as much as they can so they can hide it inside the base of the screw cap. Depending on the type of flicker and a visual inspection of the LEDs, you can take an educated guess at what is failing in the light.

Cap failure inside Driver <= very common and the flicker won't happen right away...maybe a few seconds before the cap in the driver fills up and starts crapping out. the flicker comes maybe a few seconds in and is a slower flicker (fill cap=>fail=>off=>restart).

Burnt LED <= less common nowadays with lower LED pricing, manufacturers started to increase the number of LEDs inside all there products and lowering the Amps delivered to the chips to lower heat and maintain longer life. That said...failures in chips happens because manufacturing in the end will yield 1-2% failures as the best facilities and in a bulb with 100 chips, that's 2 leds out possibility for every bulb. How to tell if this is what's causing the failure? Dimming and flickering of the bulbs is common but how do you differentiate vs driver failure...looking closely at the chips (and the phosphor around it) to see if there are discoloration (browning or blackened). Also before the flickering happens you should see the bulb dim significantly because the LED that burns out first are usually the first ones in the circuit (they get the most heat) and when the LEDs fail they block voltage and amp to the rest of the circuit. Before complete failure, the bulb will dim significantly and stay that way followed by completely turning off or flickering.

Your solution to change the bulbs is the best option and for any bulb that's Energy Star rated, manufactures are required to provide 3 year warranty on all bulbs.

This is my first post and I may have been ramblin' a bit but this thread is awesome. I've ran into this problem before with large scale commercial property upgrades and sometimes it is just the bulb.


----------

