All LEDs in House Flicker In Sync - PoCo No Help

[ELA]

This is amazing. Thank you for sharing. And yep, it is the same power company PEC.

For us, the flickering duration is around 2-3 seconds, far less than in this video. It happens at all hours, day and night, at completely random intervals. Sometimes, it'll happen again in a matter of seconds. Other times, it could be a few minutes - or longer. And like a car mechanic, it rarely happens when PEC or other electricians are here. It affects every lamp in unison. I can be standing in the living room (central point of the house) and observe flickering across 6 different circuits simultaneously.

Power company has ruled themselves out (they're VERY stubborn and proud of their infrastructure) but I'm not so sure. It's getting them to dig deeper that is frustrating.

Hello jaronbrass,
I found your flicker issue quite a challenge and an interesting discussion.

I hope that Gar did not put you off. Would love to hear what progress you may have made.

The possibility for TWAC communications to upset anything based on a zero-cross reference seems to be a common issue.
I did some google research on it since reading this thread. Leaves me wondering how wise it might have been to introduce such a communications scheme over the power lines. So many devices rely on a repetitive zero cross reference. I have a home automation system ( Insteon) that is such a device.

Depending on the characteristics of the trigger signal, that is provided to a particular Triac device, may determine how well it rejects a distorted zero cross waveform.
Might you have contacts at Lutron engineering that could provide equipment to monitor your power lines, such as Oscilloscope to look for interference signals around zero cross? If you have access, can the Lutron design engineers provide you with details as to how their trigger signal characteristics might react to TWAC zero cross distortions?

 

[HEYDOG]

Troubleshooting a particularly interesting problem. As background, I'm an engineer and a Lutron-certified sales engineer. This issue is occurring in my primary residence, which I use to demonstrate Lutron's lighting and shading solutions to prospective customers. This issue is having an impact on my business since it's difficult to showcase the benefits of these technologies when they misbehave.

We built this house with a reasonably well-known builder in Texas last year. We occupied in late November. During one of our final walkthroughs, we noticed some intermittent (2-3 second) flickering on the builder-grade chandelier installed in our foyer. At the time, we reported it on the punch list, and the electrical contractors and our third-party home inspector found no issues.

We come to find out that ALL lights in the house flicker in sync, for about 2-3 seconds, and then stop. The time between flickering is random, but you can be in one room and observe the different circuits adjacent all flicker in sync.

House is serviced by Pedernales Electric Cooperative (PEC) with 200A service. Main panel is Eaton with BR breakers. 240V breakers for the dryer, AC, oven, and sub-panel (90A) live on the outside of the house. The interior sub-panel is also Eaton with BR PON breakers. Lighting/socket circuits are 15A with AFCI breakers per code. Other circuits are 20A with a mix of standard breakers or combination AFCI/GFCI breakers depending on the service area. Overall, interior wiring looks pretty good.

We've replaced all mechanical toggle switches in the house with Lutron RadioRA2 components. We're using RRD-HN6BRL hybrid keypads, RRD-6ND/10ND dimmers, RRD-PRO dimmers in a few spots (these will replace the 6/10ND over time), and RRD-8ANS switches for things like ceiling and exhaust fans. Tabletop lamps are connected to RRD-3PD dimmers. Neutrals are connected everywhere.

Bulbs are Cree CR6T retrofit downlights up to 1600 lumens. Cree A19/A21 bulbs in screw-in fixtures. We yanked everything builder grade.

I have used this setup for years now. Bulbs are on Lutron's compatibility lists. Dimmers are trimmed properly. This has never been a problematic scenario except for here.

The flicker happens across ALL lights, whether downlights, sconces or plugged into sockets, in sync. Lights plugged into sockets will flicker with or without the plug-in dimmer module.

We've had a string of electricians out to diagnose. None can find fault with any inside wiring, although none have actually opened anything up to take a look. They keep blaming the Lutron gear and ignoring that this was an issue long before any retrofit work was done.

The power company has also been out multiple times. They found loose connections in various areas on their side of the main panel and supposedly tightened everything.

In total, the PoCo:
- bypassed their smart meter for about 8 hours and lights still flickered
- tightened connections and lights still flickered
- installed a voltage recorder and power quality monitoring equipment for 3 days

The PoCo has tried to blame EMF from our city's smart water meters, but I'm not buying it.

The data from the voltage recorder is interesting. They observed momentary 100A+ on one leg at roughly 5-minute intervals. They can't explain what it is. Neither can any electrician. The house is a natural gas house with 2 gas water heaters, gas furnace, gas range, etc. There's nothing installed that should cause that kind of reading. Which makes me wonder how accurate the data is.

So now the question... are these related? Or two separate issues? What should we be looking for? The neighbors we do NOT share a transformer with said their lights were flickering, and the builder replaced the bulbs, and the problem appears to have gone away... but they are not using dimmers like we are, which exacerbates the flickering. The house we do share a transformer with is also new and for sale, but I haven't spent enough time in it to determine if the problem exists there, too.

I'm attaching the power company data. This was captured in January. We were using heat at the time - no AC.

PoCo has basically washed their hands of this, but I'm hoping experts can weigh in. The voltage on the last page does seem to fluctuate more than I've seen in other homes.

I appreciate any insight.

I have had similar problems happening in new house that I wired a few years ago. Only in a certain room with dimmer. Used top of the line fixtures, led’s, and dimmers. Lights would flicker randomly. Tried replacing dimmers, bulbs. Checked all connections and problem still existed. Replaced dimmer with regular toggle switch and had no more issues. Never did come up with why lights would flicker with dimmer. The house wasn’t on the market yet so I eliminated the dimmer because I knew who ever bought it…would think that it was a wiring issue. Besides making them crazy! I see that once your neighbors replaced their dimmers their issue seem to go away….if I understand you correctly! I am not sure how a dimmer in one room could effect lights in another room even if on the same circuit. May be worth a try seeing what would happen without dimmers As a troubleshooting method. Would not cost much to give it a try! If the flickering stops…you can go from there. Just my opinion! Hire a electrician that is good at troubleshooting!

 

[HEYDOG]

I have had similar problems happening in new house that I wired a few years ago. Only in a certain room with dimmer. Used top of the line fixtures, led’s, and dimmers. Lights would flicker randomly. Tried replacing dimmers, bulbs. Checked all connections and problem still existed. Replaced dimmer with regular toggle switch and had no more issues. Never did come up with why lights would flicker with dimmer. The house wasn’t on the market yet so I eliminated the dimmer because I knew who ever bought it…would think that it was a wiring issue. Besides making them crazy! I see that once your neighbors replaced their dimmers their issue seem to go away….if I understand you correctly! I am not sure how a dimmer in one room could effect lights in another room even if on the same circuit. May be worth a try seeing what would happen without dimmers As a troubleshooting method. Would not cost much to give it a try! If the flickering stops…you can go from there. Just my opinion! Hire a electrician that is good at troubleshooting!

I am not an Engineer and am not trying to be insulting…..just trying to be helpful any way I can!

 

[Joethemechanic]

I think I'd try powering the house with a portable generator. If that solves the problem, you know it's on the poco side

 

[jaronbrass]

I think I'd try powering the house with a portable generator. If that solves the problem, you know it's on the poco side

Working on this now... I have an electrician coming out to install the necessary components.

 

[jaronbrass]

Hello jaronbrass,
I found your flicker issue quite a challenge and an interesting discussion.

I hope that Gar did not put you off. Would love to hear what progress you may have made.

The possibility for TWAC communications to upset anything based on a zero-cross reference seems to be a common issue.
I did some google research on it since reading this thread. Leaves me wondering how wise it might have been to introduce such a communications scheme over the power lines. So many devices rely on a repetitive zero cross reference. I have a home automation system ( Insteon) that is such a device.

Depending on the characteristics of the trigger signal, that is provided to a particular Triac device, may determine how well it rejects a distorted zero cross waveform.
Might you have contacts at Lutron engineering that could provide equipment to monitor your power lines, such as Oscilloscope to look for interference signals around zero cross? If you have access, can the Lutron design engineers provide you with details as to how their trigger signal characteristics might react to TWAC zero cross distortions?

I've reached out to Lutron, but they're not much help. This house is wired similarly to my previous home. I had no flicker there. The PoCo used wireless smart meters - no TWACS. We can't find anything in the house that would be contributing.

I do have a few dimmers that can be programmed to support forward or reverse-phase dimming. Those that can, are set to reverse. It doesn't help. The attached lamp behaves better, but is still subject to the flickering.

 

[jaronbrass]

I have had similar problems happening in new house that I wired a few years ago. Only in a certain room with dimmer. Used top of the line fixtures, led’s, and dimmers. Lights would flicker randomly. Tried replacing dimmers, bulbs. Checked all connections and problem still existed. Replaced dimmer with regular toggle switch and had no more issues. Never did come up with why lights would flicker with dimmer. The house wasn’t on the market yet so I eliminated the dimmer because I knew who ever bought it…would think that it was a wiring issue. Besides making them crazy! I see that once your neighbors replaced their dimmers their issue seem to go away….if I understand you correctly! I am not sure how a dimmer in one room could effect lights in another room even if on the same circuit. May be worth a try seeing what would happen without dimmers As a troubleshooting method. Would not cost much to give it a try! If the flickering stops…you can go from there. Just my opinion! Hire a electrician that is good at troubleshooting!

The neighbors are still using toggle switches. Our lights flickered, even with the toggles. The more I chase this, the more I think it's the TWACS issue and LEDs that can't handle voltage fluctuations as well as others do.

 

[tortuga]

If it is the TWACS and POCO is stuck with it (they wont fix it), you could have the electrician move the lighting loads to a small sub panel and feed it with a double conversion UPS. It would be some work but the bonus is you'd have lights during (brief) power outages.
I did this for a customer whom had a large home office with servers, but I just did her office and servers.

 

[ELA]

In total, the PoCo:
- bypassed their smart meter for about 8 hours and lights still flickered
- tightened connections and lights still flickered
- installed a voltage recorder and power quality monitoring equipment for 3 days

Is it correct that the smart meter was not bypassed when the current probe monitor was in place and recorded the 100A peaks.
At what location was the current probe installed, before or after the meter ( in your breaker panel or outside) ?
Any chance you can get access to someone with an oscilloscope, with voltage and current probes? In order to get a much finer time frame capture of when the current peak occurs in relation to a single cycle or two of the voltage waveform?

 

[ptonsparky]

If it is the TWACS and POCO is stuck with it (they wont fix it), you could have the electrician move the lighting loads to a small sub panel and feed it with a double conversion UPS. It would be some work but the bonus is you'd have lights during (brief) power outages.
I did this for a customer whom had a large home office with servers, but I just did her office and servers.

Double conversion should work, but I would not like having to explain that added expense to a potential customer.

 

[hbiss]

Bulbs are Cree CR6T retrofit downlights up to 1600 lumens. Cree A19/A21 bulbs in screw-in fixtures.

you could have the electrician move the lighting loads to a small sub panel and feed it with a double conversion UPS.

Yeah, right. Before I did that I would throw all those LEDs in the garbage and replace them with incandescent.

-Hal

 

[AdamTeeScott]

@jaronbrass I too find this interesting. I believe these are two separate issues. The amp spike sounds like it's a normal part of the smart meters based on the aforementioned posts.

The flickering however is very familiar to me.

I had a nearly identical issue on a whole-house remodel I did a few years back. Four months after the reno, customer called complaining about flickering on his can lights with Lutron dimmers.

Like you, I called Lutron. Helpful ideas but didn't work.
I temporarily bypassed the AFCIs. Nope.
I pulled the meter and retightened EVERY termination. Nope.
I called the PoCo in Louisville and they came out to inspect.
Now, this was an underground service so the first joint they checked was their in ground splice. No issues.
Then they climbed the pole and found that, following a bad ice and wind storm that weekend, the GROUND had a loose, intermittent connection.
They re-spliced it and it's been fine since 2018.

Hope this helps.

 

[tortuga]

Yeah, right. Before I did that I would throw all those LEDs in the garbage and replace them with incandescent.

-Hal

That would work for me but not the OP, I keep a few incandescents in my house becasue they dim nice,
however remember the OP says :

I'm an engineer and a Lutron-certified sales engineer. This issue is occurring in my primary residence, which I use to demonstrate Lutron's lighting and shading solutions to prospective customers.

This issue is having an impact on my business since it's difficult to showcase the benefits of these technologies when they misbehave.

It would be interesting to see a few other major brands of dimmers tested in this demonstration house.

 

[CutToTheChase]

@jaronbrass Don't keep us in suspense! Do you have an update? Did you manage to run the house off of a generator? Have you double triple checked your grounding system?

 

[jaronbrass]

@jaronbrass Don't keep us in suspense! Do you have an update? Did you manage to run the house off of a generator? Have you double triple checked your grounding system?

Not sure where my update went!? ELA had asked, and I had responded that I had 2 additional electricians come out to the house. The most recent visit took hours and we opened every accessible junction. We found some items needing cleanup, but nothing that would contribute to the flickering. One of my neighbors introduced me to another guy and I'm having him come out soon with an oscilloscope. He is also experiencing flickering, and we're both talking to attorneys now. Had we known about TWACS I can guarantee you I would not have built in this PoCo's service area.

Both electricians advised against the generator as they can introduce dirty power.

We also have checked the grounds multiple times. The house has 2... a UFER and a ground rod. The PoCo (PEC) requires the latter. All operating as intended.

I have been experimenting with other brands of LED lamps, namely Philips, and just when I got my hopes up, they, too, misbehaved.

 

[Joethemechanic]

Both electricians advised against the generator as they can introduce dirty power.

Well I was suggestring a good generator. Not some cheap 3500 watt 5 year old thing that takes 8 pulls to start with some slop in the main jet that makes it run lean and causes the governor to hunt.

oscilloscope

None of these guys have a scope? How do they know what power is clean and what isn't. Scopes are cheap now

 

[gar]

230628-1139

You need to start a new thread without the excessive burden of your graphs. You list yourself as an engineer. I doubt you are an electrical engineer.

There are useful ways to study your problem, but your very burdensome bloating of the thread with your unreadable graphs does not help solve your problem.

I just did a quick simple test on a CREE 815 lumen, 2700 K, 9.3 W, 120 V bulb that is several years old. This test was sine wave excitation, and light intensity was quite constant from 90 to 140 V 60 Hz. Below this it dims quite well.

Your first major problem is to try to determine whether the problem is external ( meaning before ) your main panel. If before it is most likely a power company problem.

I assume you are sourced from a single phase source, and in turn you have a center tapped distribution transformer.

This means internally you have a two phase source. The transformer supplying such a source will likely have separate coils for these two halves. This means that when you look at voltage at the end of a distribution line there will be two different voltages. Likely close to each other in magnitude. The transformer can be considered as a single primary, and two separate secondaries. At the utilization point some distance from the transformer we have a neutral wire from the transformer center tap, and two hot wires. Each of these wires has resistance, and we can assume these distribution resistances are equal ( same size wire and length ).

At the end of these wires, if we have a load on one phase, then there are two nearly equal voltage drops. One on the hot wire and one on the neutral. There is also some drop on the internal impedance for the loaded side in the transformer. A small part of the transformer internal impedance will be shared with the unload side of the transformer secondary.

These two drops ( line and internal ) reduce the load voltage a small amount.

The drop on the neutral path actually makes the voltage on the unloaded side increase slightly. Usually this increase is about 1/2 the drop on the loaded side.

Now suppose you load both phases with the same load magnitude on each phase, then the voltage on both phases drops.

This information can start to help you identify if the problem is internal or external.

Quit including your bloated plots. Start a new thread.

.

 

[Flicker Index]

https://www.led-drivers.com.au/blog/ripple-voltage-injection-may-cause-led-lights-flicker
https://productfinder.illuxtron.com/wp-content/uploads/2016/05/Report-Flicker-effects-and-causes.pdf

I don't know the signaling protocol used on the states side, but this looks like a good starting point of investigation. Quotes are from

http://www.cired.net/publications/cired2013/pdfs/CIRED2013_0256_final.pdf

"CUSTOMER’S COMPLAINTS RELATED TO RIPPLE CONTROL SIGNALS In the recent years, Endinet has registered some power quality (PQ) complaints from the customers, such as light flicker, that are (most likely) related to mains controlling signals"

"One of the commercial customers has reported light flicker problem and some issues related to the noise in the sound system in the installation. From the initial PQ measurement at that installation, it was found that flicker levels are within the limits as specified in EN50160 standard. However, the 15th, 21st and some other harmonic voltages are found to be quite large, exceeding the standard limiting values. It was also noticed that the occurrence of the customer’s reported problems approximately coincide with the time slots of sending the ripple control signals. "

 

[winnie]

I remember reading this thread back when it started. Re-reading I am noticing something interesting in the original current traces.

In most homes, large loads are 240V. These are things like the dryer, central AC, electric heat, etc.

When a large load switches on, you should see the current jump on both supply legs at exactly the same time. So there should be some significant correlation on the current on the two service legs.

But if you look at the traces, you will see 30-40A jumps on one leg that don't match the other. In fact the two traces look nothing alike.

So I question if these traces are interpreted correctly.

-Jon

 

[Flicker Index]

The spikes that go around the clock with essentially the same interval around the clock on the top graph suggests its the side of 120v that has the refrigerator on it.