Lights in house flicker while charging new Model 3

[dougiegoindeep]

Wow, thank you, everyone, for your feedback. I'll try (and fail) to respond to everything. Some more info:

-I called Eversource (electric utility) to notify them of the issue. They sent someone the same day to check the service to the building. When I got home I noticed the problem was still present so I called them the next morning and they said that a tech noticed an issue with the "cutout" in the transformer and fixed it. I don't know exactly what that means. But it didn't solve my problem as the lights inside were still flickering after this repair. Eversource said they would come back out again.
-Upon a second visit, the Eversource tech said he didn't see anything wrong and that I should follow up with an electrician to check inside my unit. He said there was a single transformer feeding only the 3 unit building that I am in and that a transformer like that should be capable of handling multiple buildings.
-The electrician came this morning. He didn't find anything obvious in the panel or with the lights were I noticed the flickering. He also described it as the lights dimming rather that flickering which is a more accurate description (they are not flickering like an old tube light that is going out like someone asked up above). He said he measured the power draw while the car was charging at 33 amps rather than the 40 amps that it says in the app (not sure if that is relevant, he didn't seem concerned by it). He said there was no fire hazard and it is probably just a nuisance issue related to the LED lights (or the zwave dimmers). He said maybe there is interference on the neutral line causing them to behave the way they are. He suggested replacing one of the lights with an incandescent bulb to see how it reacts when the car is charging which I will try a bit later. He said if that starts flickering while charging (beyond just when the charging starts) then it probably is related to the supply coming from the utility outside the building and I should follow up with Eversource again.

 

[dougiegoindeep]

It could be a sign that you have a poor connection upstream from the car that the whole house is seeing as well.

Eversource said everything outside was OK.

... could be a sign of a loose or burned neutral. Or something going on in your panel.

Eversource said everything outside was OK and electrician said everything in the panel was OK.

It could also be in the meter pan or out at the utility transformer.

Eversource said everything outside was OK.

I am wondering if the voltage sags a bunch after things heat up? (though if it sags too much the Tesla should throttle back charge speed or stop charging for safety)

It seems to be stable once it gets up to 40 amps.

Does the degree of flickering depend on what the dim level of the dimmers is?

I don't think so? It is more noticable when the lights are dimmer but I think that is just because if it dims from 20 to 10 that is more noticable than 100 to 90.

Is it a particular category of LED that flickers?

They are all the same lights I believe.

If you look at the charging screen in the car, is the charging current bouncing around?

Only when it starts. After it hits 40 amps it is stable.

I too, have a hard time understanding why this would not happen with the Model S, if the charging behavior is basically identical. To be clear, the Model S still does not cause flickering, right (I know it has been ok in the past...that has not changed)?

I have not yet noticed the dimming while the model S charges (except when it starts).

Did you change anything else about the charging setup when you added Model 3?

No. They share the same UMC that has been left plugged into the outlet outside.

Maybe a neighbor recently added a big load too on the same transformer and this isn't 3 related atall? Hot tub EV????

I don't think so. Eversource said the transformer only feeds my 3 unit building. One neighbor is away (and has been for a while). The other is a renter and wouldn't have added anything crazy. No other EVs in the building.

I don’t know the tolerance range for the S, but it turned out, my outside compressor was bad, and, the inside unit was 23 yrs old, and I replaced both. No more issues.

I don't think this is related. The issue started before I started using AC this season.

Some questions for you:

• Is your electrical service overhead (aerial drop to your house) or underground?
• If you go look at your transformer (generally either a green box on the ground, or a tan colored canister up on one of the closest poles) - it will generally have a big number on it like "15, 25, 50, 75". That is its KVA rating. What is that number?
• How many houses are fed from that one transformer? (easier to tell if overhead, but often times you can kind of figure it out even if ground mounted).

I can't see what it says on the transformer. It only feeds my building, 3 units.

I have had somewhat similar issues with an overheating dimmer (in a wall box with a couple other dimmers that were also hot). Replacing the dimmer fixed it.

I don't think it would be a bad dimmer as it is noticable in at least 4 different lights on different dimmers.

Flicker like when a fluorescent tube is going out or pulsate?

A quick dimming, not like a light going out.

This sounds like a transformer issue outside your home. I'd contact your utility if you can't resolve it. Did you ever check your voltage at your panel?

Eversource and electrician said it was OK.

 

[mikef137]

Eversource said everything outside was OK.



Eversource said everything outside was OK and electrician said everything in the panel was OK.



Eversource said everything outside was OK.



It seems to be stable once it gets up to 40 amps.



No. They share the same UMC that has been left plugged into the outlet outside.



I don't think so. Eversource said the transformer only feeds my 3 unit building. One neighbor is away (and has been for a while). The other is a renter and wouldn't have added anything crazy. No other EVs in the building.



I don't think this is related. The issue started before I started using AC this season.



I can't see what it says on the transformer. It only feeds my building, 3 units.



I don't think it would be a bad dimmer as it is noticable in at least 4 different lights on different dimmers.



A quick dimming, not like a light going out.



Eversource and electrician said it was OK.

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I use LED lighting exclusively in my house and all are connected to Insteon home automation dimmer switches. The Insteon uses a powerline protocol for communication between the automation controller and the dimmer switches. The LED lights do flicker while there is Insteon communication on the power line, but did not flicker when I was using incandescent bulbs. I think my Insteon dimmers are a bit sensitive to noise on the powerline when attached to the light load of the LED bulbs. The same "noise" likely propagated through to my incandescents but was not perceivable as it would have been such a tiny percentage of the load.

 

[bone man]

I have the same flicker issue only with certain LED bulbs in our kitchen. I turn down the charging amps on the Model 3 to 15 amps then no flicker.

I had similar flicker in LED bulbs with old dimmers Replaced with new dimmers and flicker stopped.

 

[Castlerock]

All this is anecdotal. But, I had a similar issue after installation of a 60A circuit to power the Tesla wall unit. After a few weeks I started to get flickering lights when charging, lowering the current seemed to help. But we did notice some crackling, barely audible at the breaker box. End result was a defective fuse at the box.