Odd dimming issue

Curious if anyone has any insight on what might be going on with my environment.

Had installed about 15 Blues a month or so ago and everything working well. Went through firmware upgrade. Everything working even better.

This past week, we had a local power outage where we were without power for about 30 hours due to some local wind damage, so lots of crews out fixing power poles, etc. When the power came back on, we start noticing that all the light dim settings that we had configured are now much brighter than the particular setting was before and can no longer dim things down to very low levels. Low level still pretty bright.

Voltage measures 126v at outlets. Issue is across every light switch I have.

I’ve contacted power company to see if something is up, but curious if anyone has any thoughts as to what could be going on here.

The power company might have moved your house to another phase of the lines. They try to keep neighborhoods balanced on the 3 phases going into a substation. and if one starts to get used way more then another, they will move customers to another phase sometimes. During the outage, likely were replacing equipment and could have re-balanced the phases there. They can do this easily on the pad mount transformers. But seeing your outlets are at 126, that is way higher then normal. Mine here in Phoenix, have always measured 118 or so, give or take a few volts.

LED lighting is sensitive to this and if there is a higher voltage, they will be brighter at diffrent levels. WHich is what you are seeing. Like when my wife is doing her hair and kicks on her Dyson Air brush (blow drying built into a hair styling tool thingie) but all the lights on all circuits dim just a hair becuase it pulls enough amprage to drop the voltage just a hair (pun intended) and I will see all the LED lights in the entire house drop just that little bit where if it was dark, its enough to make a differance big time.

Contact your power co and make sure your 126 is normal for your area. I’ve done electrical work (res/com) and never really seen the output of a powerline that high. You might have faster wear on devices with motors and other sensitve electronics, even LED lightbulbs start to go out sooner becuase it frys the electronics on the PCB. The power co will send a tech out to do a phase balance test to check on your lines or at your transformer, they can drop the output voltage on the lines at percentages bringing it back down to normal. They dont charge for this. Just call and say you’d like a tech to verify the incoming voltages on your house as your testing it and showing its a bit high.


I wonder if your devices switched to leading edge dimming from trailing edge. That definitely makes a minimum dim level difference with a lot of LED lights.

How would I determine this and would this be caused by the voltage change I have seen? (making an assumption that it is higher than it was)

Seeing as high as 127.5 volts today.

Local power company came out and checked things. They acknowledge that it is on the high side but “still within spec”. They indicate that some work in a nearby substation is the cause of the higher volts and that I should see it come down a bit after they are complete. All magic to me… :slight_smile:

Thanks for the comments

This is awesome info, thanks!

That’s good. And since the voltage is high, your lights will be brighter. And if they bring it back down to normal, then lights will be normal again.

Interesting that my switches are now dimming properly. Not sure if just the act of powering off the entire household by pulling the meter fixed things, or if they could have made some other change. All seems to be back to normal despite voltages still being high.

@RandyT I had a brief power hit a few weeks ago, and when the power came back lights on my blue dimmers were flickering or had a slight dim. I air gapped them for a few seconds to restore functionality. My blue fan switches were not affected in the same way.

Interesting @robby I have to believe that this was probably the solution for my issue as voltage remains high but everything back to working as expected after the powercycle.