Issues with a slight LED flicker - Not Dimmer/Connection related

[sparkie1]

Hello all. So, I was doing some interwebs searching, and found this particular post:

Flickering LED fixtures

Anyone have some experience with namely led lighting from Menards, which is mainly Patriot Lighting. Customer supplied fixtures and after I installing the very first of them I noticed a slight flicker. I continued installing with some other models to see if it was just a one-off problem, nope...

forums.mikeholt.com

I noticed it was never resolved, and I'm dealing with something similar. Here is the rub. We have installed around 300 LED disk lights / wafer lights / surface mount cans / whatever you want to call them. In three houses now, we have had issues with a slight intermittent flicker. It is a few "pulses" where the lights drop slightly in intensity and then level off. It happens at seemingly random times as well. Sometimes its just a couple pulses. Once I saw that it was 4 or 5 pulses. That is the symptom. Now, a bit more information on this. I think it would be best to organize it as a list.

This happens:

1. With or without a dimmer.
2. On multiple lighting circuits on both L1 and L2.
3. Voltage variation according to two separate meters on L1 and L2 only show around 4/10 volt drop or rise.
4. Across 4 different types of LED disk lights, and at least 10 different types of LED lamps. I personally witnessed it on Patriot lighting 4" LED cans, and three types of 6" disk lights, as well as both standard E26 base LED lamps and LED candela-type lamps in a chandelier.
5. Even when only a single disk light is the only light on in the house (lighting wise).
6. This only happens on our local rural power coop. It does not happen in town.
7. I personally terminated the service equipment and the branch circuits. I also went back through to verify connections were solid. (The flicker doesn't manifest as a bad connection seems to do.)
8. I have confirmed that the POCO in town uses an RF mesh network for their smart meters, and I have confirmed that the coop uses PLCC for their smart meters.

I'm posting here because with the pattern, I'm starting to think that this flicker might have to do with the coop's smart meter communications. The EE from the coop told me that they communicate at 60Hz, but I don't believe that would be possible, as the communications would get interference from the power signal. I googled that PLCC uses 24 - 500 kHz, and I also pulled up a data sheet for a PLCC modem, which specified the 23.5 to 95 kHz ranged, and was rated for 50 Hz and 60 Hz mains.

I really wanted to pick some brains on this issue, especially when I saw this recent thread was closed with no solution. We questioned the information that PLCC communicates over 60 Hz. The POCO is putting a power quality meter on the service as well, but their PLCC isn't abnormal, it is there by design. I'm thinking about trying a low pass filter in the form of a signal conditioner rated for 0-400Hz or seeing if there is anyway to stop communications for a bit and see if the problem stops.

I'm interested to hear if anyone else is or has fought this before or knows anything about it. Right now we are following the PLCC line to try and eliminate that as a source of noise. It is the primary and clear difference we see between the POCO in town and the coop. Of course, coop can't do much about it if that is the case, but at least we would know about the issue.

 

[synchro]

Perhaps the coop is using TWACS for its communication with smart meters. See the thread at the following link:

https://forums.mikeholt.com/threads/twacs-flickering.2555379/

 

[sparkie1]

Perhaps the coop is using TWACS for its communication with smart meters. See the thread at the following link:

https://forums.mikeholt.com/threads/twacs-flickering.2555379/

Thanks a ton. that at least shows me that this is a verified issue with some of the technology. I've asked what they use and all I can get is that "it is PLCC at 60 Hz on a 22 degree sin wave system and it sends data every 8 hours". I'm not seeing how you can send data at 60Hz on a 60Hz system or what a "22 degree sin wave system" means without any context. I'll make sure to update this as we go and with what the rural coop says after they get the data logger back.

I have an analog discovery I might put on the mains voltage and see if I can see distortion in the voltage waveform. I'm going to arbitrarily throw a power line filter from automation direct on the lighting circuit and see what it does.

 

[Flicker Index]

It's certainly possible. You know how you hear a pop in the radio when you flick off the bathroom fan? Gen 1 Cree LED had a poorly designed ballast and the kickback from the shaded pole motor confused the ballast and caused the Cree LED lamp on the same circuit to shut down for a tenth of a second or so. Those were dimmable lamps.

Are your luminaires dimmable? The control signal could be causing the LED ballast to sense it as phase control dimming attempt and glitching out.
It could also be that you have a soft line due to smaller kVA transformer in the rural setting and actual voltage dips from load is causing the luminaire to flicker. The amount of fast transient notching and dips being passed down to visible flicker is entirely dependent on the LED ballast design. Try connecting one on the same outlet as a fridge. Does the flicker follow the compressor starting? Rural power service is almost always less stiffer than urban power.

 

[LarryFine]

If only some LEDs flicker, try swapping one of each and see whether it stays with the bulb or the location.

Also see if substituting an incandescent in one light alters the flicker on the rest of the group's LEDs.

 

[mopowr steve]

I am

Hello all. So, I was doing some interwebs searching, and found this particular post:

Flickering LED fixtures

Anyone have some experience with namely led lighting from Menards, which is mainly Patriot Lighting. Customer supplied fixtures and after I installing the very first of them I noticed a slight flicker. I continued installing with some other models to see if it was just a one-off problem, nope...

forums.mikeholt.com

I noticed it was never resolved, and I'm dealing with something similar. Here is the rub. We have installed around 300 LED disk lights / wafer lights / surface mount cans / whatever you want to call them. In three houses now, we have had issues with a slight intermittent flicker. It is a few "pulses" where the lights drop slightly in intensity and then level off. It happens at seemingly random times as well. Sometimes its just a couple pulses. Once I saw that it was 4 or 5 pulses. That is the symptom. Now, a bit more information on this. I think it would be best to organize it as a list.

This happens:

1. With or without a dimmer.
2. On multiple lighting circuits on both L1 and L2.
3. Voltage variation according to two separate meters on L1 and L2 only show around 4/10 volt drop or rise.
4. Across 4 different types of LED disk lights, and at least 10 different types of LED lamps. I personally witnessed it on Patriot lighting 4" LED cans, and three types of 6" disk lights, as well as both standard E26 base LED lamps and LED candela-type lamps in a chandelier.
5. Even when only a single disk light is the only light on in the house (lighting wise).
6. This only happens on our local rural power coop. It does not happen in town.
7. I personally terminated the service equipment and the branch circuits. I also went back through to verify connections were solid. (The flicker doesn't manifest as a bad connection seems to do.)
8. I have confirmed that the POCO in town uses an RF mesh network for their smart meters, and I have confirmed that the coop uses PLCC for their smart meters.

I'm posting here because with the pattern, I'm starting to think that this flicker might have to do with the coop's smart meter communications. The EE from the coop told me that they communicate at 60Hz, but I don't believe that would be possible, as the communications would get interference from the power signal. I googled that PLCC uses 24 - 500 kHz, and I also pulled up a data sheet for a PLCC modem, which specified the 23.5 to 95 kHz ranged, and was rated for 50 Hz and 60 Hz mains.

I really wanted to pick some brains on this issue, especially when I saw this recent thread was closed with no solution. We questioned the information that PLCC communicates over 60 Hz. The POCO is putting a power quality meter on the service as well, but their PLCC isn't abnormal, it is there by design. I'm thinking about trying a low pass filter in the form of a signal conditioner rated for 0-400Hz or seeing if there is anyway to stop communications for a bit and see if the problem stops.

I'm interested to hear if anyone else is or has fought this before or knows anything about it. Right now we are following the PLCC line to try and eliminate that as a source of noise. It is the primary and clear difference we see between the POCO in town and the coop. Of course, coop can't do much about it if that is the case, but at least we would know about the issue.

I am that original poster.
As I remember I had the rural power company on my job even remove the smart meter and temporarily install a regular one,
Still did not correct the problem. And the crew that was there didn’t have much of any answer as to what it could be.
Eventually we changed all the problematic Patriot LED and others fixtures out with different manufacturers that utilized a little more filtering, you really have to look hard to notice the flicker now.
Still is a quandary.

 

[sparkie1]

It's certainly possible. You know how you hear a pop in the radio when you flick off the bathroom fan? Gen 1 Cree LED had a poorly designed ballast and the kickback from the shaded pole motor confused the ballast and caused the Cree LED lamp on the same circuit to shut down for a tenth of a second or so. Those were dimmable lamps.

Are your luminaires dimmable? The control signal could be causing the LED ballast to sense it as phase control dimming attempt and glitching out.
It could also be that you have a soft line due to smaller kVA transformer in the rural setting and actual voltage dips from load is causing the luminaire to flicker. The amount of fast transient notching and dips being passed down to visible flicker is entirely dependent on the LED ballast design. Try connecting one on the same outlet as a fridge. Does the flicker follow the compressor starting? Rural power service is almost always less stiffer than urban power.

These are in fact dimmable fixtures and lamps. The flicker does not follow any appliances starting. I've tried this with the microwave and furnace. This problem doesn't seem to be like that, though. In my experience the lights tend to just dim a bit when the appliance kicks on. This type of flicker is several short pulses.

If only some LEDs flicker, try swapping one of each and see whether it stays with the bulb or the location.

Also see if substituting an incandescent in one light alters the flicker on the rest of the group's LEDs.

We have two incandescents in one of the areas the owner works in a lot to at least see if they dim as well. The incandescents do not flicker while anything LED will. We have tested too many brands of lamps and fixtures for this problem to be a fixture. That doesn't mean we won't find a fixture that will work, but it happens across LED lamps and fixtures of different types, sizes, colors, brands. It's just too prevalent.

I am

I am that original poster.
As I remember I had the rural power company on my job even remove the smart meter and temporarily install a regular one,
Still did not correct the problem. And the crew that was there didn’t have much of any answer as to what it could be.
Eventually we changed all the problematic Patriot LED and others fixtures out with different manufacturers that utilized a little more filtering, you really have to look hard to notice the flicker now.
Still is a quandary.

Thank you. I observed the flicker in their closet, which has 4" Patriot Lighting disks, but the other stuff in the house isn't. I wish we could swap out lighting. Something to bring up about your situation that we talked about when considering putting in a non-smart meter to see how it went. Just because you take one smart meter out doesn't mean there aren't still other smart meters transmitting on the utility network. If the transformer were to isolate the signal, then the smart meter wouldn't work. So putting in a normal meter wouldn't do it.

 

[Flicker Index]

LEDs are of low enough wattage that you could hook up two thermostat or door bell transformers back to back to work as an isolation transformer. While this won't do a thing about voltage sags, the iron core would block the passage of superimposed signal. If this stops the flicker, then your theory might be correct.

If it's the interaction as you mentioned, surely other customers would be reporting the same issue.

 

[sparkie1]

LEDs are of low enough wattage that you could hook up two thermostat or door bell transformers back to back to work as an isolation transformer. While this won't do a thing about voltage sags, the iron core would block the passage of superimposed signal. If this stops the flicker, then your theory might be correct.

If it's the interaction as you mentioned, surely other customers would be reporting the same issue.

Other customers have reported the issue. Three separate houses now for us. I think most people will just ignore it, but of course others do notice it and it is a big deal to them. I ordered a line filter today. I'll try the transformer suggestion as well when I go out there.

 

[LarryFine]

LEDs are of low enough wattage that you could hook up two thermostat or door bell transformers back to back to work as an isolation transformer. While this won't do a thing about voltage sags, the iron core would block the passage of superimposed signal. If this stops the flicker, then your theory might be correct.

If it's the interaction as you mentioned, surely other customers would be reporting the same issue.

I was thinking about suggesting a 1:1 transformer.

 

[sparkie1]

Thing is, though, that the signal already passes through a utility transformer. I don't know enough about that particular subject to make a determination.

 

[gar]

220108-1120 EST

Some time back, don't know when, I commented on incandescent and LED flicker. At that time I considered the flicker of a 15 W tungsten incandescent to be about the same as an LED, I believe it was CREE.

Recent tests I found that a CREE was less sensitive than a 15 W incandescent. A short 2 V drop to the incandescent produced a detectable flicker. It was more like 8 to 10 V of the same duration to see the CREE flicker.

Try putting a 15 W incandescent side by side with an LED. How do their flickers compare?

.

 

[synchro]

We have two incandescents in one of the areas the owner works in a lot to at least see if they dim as well. The incandescents do not flicker while anything LED will. We have tested too many brands of lamps and fixtures for this problem to be a fixture. That doesn't mean we won't find a fixture that will work, but it happens across LED lamps and fixtures of different types, sizes, colors, brands. It's just too prevalent.

While it might not be applicable in your application, it would be interesting to try an LED wafer light with 0-10V dimming to see if it has significantly less flicker during modulation of the AC waveform. A 0-10V version would not need to detect the duty cycle of the AC waveform to control its dimming operation, and it therefore might be more immune to duty cycle variations than the standard LED wafers.

One example of a 0-10V wafer light is the following:
https://ledsupplyco.com/rab-dl-wafer-6-round-12w-900lm-90cri-120-277v-smooth-0-10v.html

... Something to bring up about your situation that we talked about when considering putting in a non-smart meter to see how it went. Just because you take one smart meter out doesn't mean there aren't still other smart meters transmitting on the utility network. If the transformer were to isolate the signal, then the smart meter wouldn't work. So putting in a normal meter wouldn't do it.

I believe the main cause of the flickering is the low frequency modulation of the AC waveform applied by the POCO, and not the higher frequency modulation applied by the smart meters themselves. The waveforms in the following video appear to show that the modulation applied by the POCO near the zero crossings has significant energy at the 5th harmonic of 60 Hz. And so typical powerline filters are likely to have a minimal effect in suppressing this modulation.
https://forums.mikeholt.com/threads/twacs-flickering.2555379/#post-2600391

 

[Flicker Index]

220108-1120 EST

Some time back, don't know when, I commented on incandescent and LED flicker. At that time I considered the flicker of a 15 W tungsten incandescent to be about the same as an LED, I believe it was CREE.

Recent tests I found that a CREE was less sensitive than a 15 W incandescent. A short 2 V drop to the incandescent produced a detectable flicker. It was more like 8 to 10 V of the same duration to see the CREE flicker.

Try putting a 15 W incandescent side by side with an LED. How do their flickers compare?

.

CREE has gone through several iterations of them. Do you remember those silicone rubber coated frosted glass dome ones? Those had a ballast that would get confused from inductive kick back and would briefly turn off when it sees a spike from the fan being turned off.

 

[sparkie1]

Just to update here, we have confirmed the issue to be the time sync signal from the meter PLCC communications. It is specific to the time sync signal itself rather than general communications. I'm not sure of the details on it or how they will remedy it, but they ended up timing the duration between them and noticed that they also had a time sync signal go out every 15 minutes, then they sent a manual sync signal out and it made the lights flicker. They repeated multiple times to confirm. I wasn't out there for the test, as I had class, so I also couldn't get a hard copy of the raw data they recorded to plot. Either way, that's two years, several unhappy customers, and one unhappy contractor off of our backs.

They did take my information and are supposed to be updating me when they get more information or if they can collect specific data on the signal so that we can figure out how to deal with it. Well, so they can figure out how to deal with it. I'm just the idea guy.