Slightly annoying electrical gremlin

[BudgetSlasher]

We've got a treadmill in the basement and when it is in use it cause a flicker/pulsing of lights roughly in line with the pace that is being run. I am wondering if anyone has run into this/has a way to mitigate it.

A bit more information the treadmill is on circuit A in the main panel and so far I have identified light that pulse on circuits B and C (also in the main panel), and circuit D (in a subpanel). All impacted lights are LED which are controlled by an LED compatible dimmer; the pulsing is most notable when the lights are dimmed, which is the majority of the time. So far I've noticed it in 8 different light fixtures.

A while back I tried googling this what I found didn't seem to apply here. Those were either on the same circuit (not the case here) or suggesting a loose connection (I've check the wiring on the treadmill outlet and in the panel at the breaker/neutral/ground.)

[lthenderson]

I'm not an electrical guru and I'm sure others will have a more specific answer. But I do know that anytime I have had dimmers, the dimmer switch itself always caused issues. I've just gotten rid of them and just use lighting combinations to control brightness. If I want it dim, I just turn on a small shaded lamp versus using overhead lighting, etc.

[GilesMM]

Ensure your LED lights are dimmable and compatible with the dimmer in use.


Otherwise, could be your system is overloaded and unable to supply enough power to the LED circuits to prevent them from flickering.  Check the specs of circuits and the loads on them.

[BudgetSlasher]

Ensure your LED lights are dimmable and compatible with the dimmer in use.


Otherwise, could be your system is overloaded and unable to supply enough power to the LED circuits to prevent them from flickering.  Check the specs of circuits and the loads on them.

All LEDs are dimmer compatible. Its pretty much a requirement for buying bulbs.

I haven't managed to fully trace all of the circuits... there could be a stray outlet here or there with the lights... but overload cannot be the problem for all of them. One of the circuits is 15A/1,800W has 2 LEDs @ ~9W/ea and one outlet that is used to charge stick vac @ 72W. Service shouldn't be over loaded, it is 200A and the treadmill is used at a time when most/all of the major appliances are not in use.

I'm not an electrical guru and I'm sure others will have a more specific answer. But I do know that anytime I have had dimmers, the dimmer switch itself always caused issues. I've just gotten rid of them and just use lighting combinations to control brightness. If I want it dim, I just turn on a small shaded lamp versus using overhead lighting, etc.

Yeah dimmers are finicky, we're kind of forced into them. The switched lighting includes overhead, wall sconces, wall mounted reading lights, and so on and its not always well grouped... in some rooms there can be 5 or 6 light fixtures on one switch, that excludes the basement which has a lot on one switch.

We do have a couple floor/table lamps that are used for things like reading.

I am suspecting it is either a inrush triggered voltage drop when a load is applied (such as a footfall) or inductive voltage spike when a load is removed (such as a foot being removed). Though it seems weird that it impact other circuits some of which are not physically near it in the box... now that I say that I should check and see if they are all on the same leg.

Overall I am satisfied that the wiring is sound and there isn't a fire risk. Its just a minor annoyance several mornings a week.

[bill1827]

Some LED lights seem very sensitive to AC voltage. We have some that flicker badly when the coffee machine is warming up. They are on Shelly dimmers and I haven't established whether it's the dimmer or the LED fitting. A couple of others flicker but not as noticeably.

[chemistk]

All LEDs are dimmer compatible. Its pretty much a requirement for buying bulbs.

While it's technically true that a given LED bulb will work with a given dimmer, in that the bulb will emit light - it's also not. Older dimmers modulate current to the light circuit in ways that are incompatible with most LED bulbs, in addition to the fact that there are plenty of LED bulbs that are non-dimmable.

Most of the time, if LED lights are flickering on a circuit for a given reason other than a faulty neutral or ground, or for being overloaded, then it's usually the case that you have a dimmer that's not designed for LED bulbs and/or non-dimmable LED's.

It might be worth taking a closer look at the dimmer to find a part number and see if it's designated as LED compatible. If it's not (or if it's old enough that it's reasonable to assume), it might be worth looking into a quality dimmer that's made specifically for LED's.

[BudgetSlasher]

All LEDs are dimmer compatible. Its pretty much a requirement for buying bulbs.

While it's technically true that a given LED bulb will work with a given dimmer, in that the bulb will emit light - it's also not. Older dimmers modulate current to the light circuit in ways that are incompatible with most LED bulbs, in addition to the fact that there are plenty of LED bulbs that are non-dimmable.

Most of the time, if LED lights are flickering on a circuit for a given reason other than a faulty neutral or ground, or for being overloaded, then it's usually the case that you have a dimmer that's not designed for LED bulbs and/or non-dimmable LED's.

It might be worth taking a closer look at the dimmer to find a part number and see if it's designated as LED compatible. If it's not (or if it's old enough that it's reasonable to assume), it might be worth looking into a quality dimmer that's made specifically for LED's.

Good point. We've switch color and style switches and replaced every incandescent bulb with an LED in the last 8 years, so I am confident that the box for every dimmer indicated that it was either for either LED or LED and CFL and the box for every light bulb indicated that it was dimmable.

[Bartlebooth]

Such is the state of LEDs and dimmers.  Swap either bulb or dimmer at random until you find a combination that works.  I have found that the filament-style LED bulbs seem to dim better.  But still they flickered at very low levels and died prematurely.

I have actually swapped the two dimming sconces in our nursery back to incandescent bulbs, because we like to have those dimmed to a VERY low level of light.  Smooth perfection now, all they way down to an absolutely tiny glimmer.  BTW we have modern reproduction push-button switches with a rotary knob to dim...very good control.

If LED is a must, great dimming is a must, and not randomly trying various bulbs and dimmers is a must, I would be looking at something like LED drivers that take a 0-10V dimming signal in addition to regular power, and a dimmer switch that delivers 0-10V.

[ChickenStash]

Another thing to try is swapping one bulb in the circuit with an incandescent.

I haven't dealt with having a motor involved but I have a circuit with all dimmable LEDs and a compatible dimmer that just didn't like each other and created pulsing, usually when dimmed. Replacing one bulb with a 40w incandescent seemed to add enough resistive load to the circuit and fixed the issue. Not the best plan for max energy saving, admittedly, but it was in a location that wasn't used enough to matter.

[ChpBstrd]

Consider a power conditioner:
https://mrelectric.com/blog/what-is-a-power-conditioner

[Cadman]

An o-scope on the treadmill cord would tell the tale. I suspect a high inductive component is getting back into your panel, triggered by the sudden change in load with each step on the belt. Most modern treadmills use switchers (which by their nature can be noisy).  The reason you're seeing it with these LED lights is that 1. LED power supplies tend to be as cheaply designed as possible, and have little to no filtering for such transients. 2. Their current draw is minimal, so even small transients have a highly visible effect.

LED dimmers are also susceptible; I'd be tempted to temporarily bypass it and see if conditions improve. If they do, I'd make room to add a switch in parallel with the dimmer for times when you want to work out. I had to do something similar years ago if I wanted to listen to AM radio in the same room with a ceiling light dimmer. Worked great.

[zolotiyeruki]

An o-scope on the treadmill cord would tell the tale. I suspect a high inductive component is getting back into your panel, triggered by the sudden change in load with each step on the belt. Most modern treadmills use switchers (which by their nature can be noisy).  The reason you're seeing it with these LED lights is that 1. LED power supplies tend to be as cheaply designed as possible, and have little to no filtering for such transients. 2. Their current draw is minimal, so even small transients have a highly visible effect.

LED dimmers are also susceptible; I'd be tempted to temporarily bypass it and see if conditions improve. If they do, I'd make room to add a switch in parallel with the dimmer for times when you want to work out. I had to do something similar years ago if I wanted to listen to AM radio in the same room with a ceiling light dimmer. Worked great.

^^^ This.  LEDs don't like it when there's a large, rapidly-varying, inductive load running.  When my air compressor in the garage kicks on, all of the lights on that same circuit flicker in time with it.  It's rather unpleasant.

[SnipTheDog]

Could also try some cheap filters (ferrite beads) on your line into the treadmill.  This will help if your treadmill is putting a pulse onto your AC line with every rotation from the treadmill.  Look up Ferrite Choke on Amazon for lots of options.