LED problem

[gar]

230418-1145 EDT

@jaronbrass:

I have created this new thread because your large plots are too much of a time burden. Such large plots are not needed.

You have a new home where all your LEDs flash in unison. I assume you are supplied by a center tapped utility transformer. less likely two phases of a three phase system. Two phases of a three phase system wound not likely be flashing directly in sync, however, it is possible.

I have tested CREE 9.5 W bulbs several years ago, and they had very good operating characteristics.

I would never trust what a power company tells me, unless I can get beyond low level people.

Since all lights seem to be in unison, and are CREE, I would suspect the most likely problem to be external to your main bus bars that breakers plug onto. This means I suspect problem is before said point.

I would suggest a trouble shooting procedure that first evaluates a single CREE or possibly several in some place where there is known stable power. Then at this location you perform various perturbations on supplied AC sine wave voltages, and then at several AC voltages and various voltages and turn on phase shifts. Also turn off phase shifts if that is how your dimmers work. Do these test over very large ranges to see if anything pecular occurs. This should provide some information if bulbs are a problem.

Assuming that bulbs are not likely the direct cause of the problem, then setup test equipment at the main panel, and proceed with monitoring both line voltage and current at the main panel looking for the problem.

I believe my plots that I previously referenced are in couple hundred thousand byte size..

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[tthh]

Might be interesting to replace a couple CREE's with a Philips and a Sylvania and see how they behave during the flicker events.

 

[Todd0x1]

I'd turn off the main, power the whole house (just for the lighting) off a portable inverter generator and see if they still flicker.

 

[hillbilly1]

Though the neighbors had the same problem, and the op said they were on a different transformer, sounds like a utility issue. Faulty regulator at the substation, or maybe an industrial complex that is nearby since it does it all hours of the day. The poco will deny it, then quietly fix the problem. I’ve had Georgia Power do that before. They don’t want to be liable if you claim any damages.

 

[gar]

230419-0245 EDT

jaronbrass:

As an electrical engineer you should be able to do a much better troubleshooting task than what you have done.

I can not tolerate reading your original post because of the extreme time delays that result from your large plot files. Further I have no idea how the Y and time axes are scaled and zeroed.

You need to use a good digital scope with lots of memory to look at one 120 V phase at the input to your main panel. Use a clamp on current transformer to monitor current on one input hot 120 V phase conductor. The current probe goes to one input scope channel. To a second input scope channel connect a 10X voltage probe. Let the internal scope common connection come from the scope AC cord. Thus, you do not use the comon input wire on the probe.

Now you use the scope to monitor the power company signals at a demark location close to where the power company defines the difference between you and them.

What you want to look at is the level of correlation between current and voltage . If a large and high correlation, then the problem is most likely the power company. If voltage is reasonably stable, then you look for a problem in your main panel.

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[gar]

230422-0948 EDT

jronbracss:

We need to hear from you. There are are details and tests that can probably point to where the problem is..

The first experiment you need to run is on one or more ( only a few 9.5 W CREE bulbs would be enough.) to see how they operate in a different location where line voltage is reasonably constant.

An important first test to run s to use a Variac.( a mechanically adjustable sine wave source ) to change the sine wave voltage to a single CREE bulb under test. Adjusting voltage from zero to 135 V you should see the bulb turn on at less than full intensity at possibly 50 V or so, and drop out aout 15 V. In other words there is hysteresis in ON-OFF. Brightness varys from low voltage to about 90 V, then from .this point the light intensiy is more constant as voltage is further increased.

There are no glitches in this intensity variation with voltage.

Next you use a series resistor with the bulb to change its intensity. This will allow you to vary intensity to any allowed value witin whatever range the bulb works.

A switch across the series resistor provides a means to get an instantaneous change in voltage across the bulb.

If you do these experiments, then you will get a feal of bulb operation.

This gives you knowledge on how your test bulb varies under these test conditions.

Next you use the test bulb back at your residence and see what happens there.

At the moment I won't go into details of how you proceed next. But, I believe the problem is before your main panel breaker bus bars.

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[Dennis Alwon]

@gar you cannot tell someone "As an electrical engineer you should be able to do a much better troubleshooting task than what you have done",
and then expect him to respond to you.