Washer and flickering LED lights

[Steve V]

Received a call from a residential EC today asking for help.

Wired a new home 6 months ago, inspected etc.....

When the washer runs all the LED lights in house flicker.

Washer is on a dedicated 20 amp circuit, he has checked all the neutrals and grounds up to and including 3 visits from the local power company. Also took 2 LEDs from another home that were working fine and swapped them out. Still flickering.

Any suggestions or thoughts?

Thank you.

 

[Dsg319]

Can you check feeder neutral from service to main panel to check its integrity/continuity.

Power company likely will only check from line side of the Meter/service disconnect.

Probably unlikely, but is severe voltage drop possible?

 

[Shaneyj]

Wild guess...
Not saying it couldn't be a service issue, but with poco out several times not likely.
What about washer type? Variable speed driven with possible harmonic issues?

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[synchro]

Are there lighting circuits that are not on a dimmer that have the flickering, or are all of the lights on dimmers? Just asking to see if dimmers might be involved.

If an incandescent bulb is substituted is there any flickering? If it flickers significantly, then it's likely that there are voltage drops on connections and/or wiring that is causing the problem on the LEDs lights.

You might try out LED bulbs from different manufacturers. Interference generated from a VFD in the washer might be false triggering the dimming detection circuitry within a dimmable bulb, and so you might include some non dimmable bulbs in your testing. On the other hand, high quality dimmable bulbs could have better internal EMI filtering (which would be mainly there to reduce the EMI that they generate). And so they might work out better.

If you had a 'scope to look at the AC voltage waveform when the flickering occurs that would help in diagnosing the problem. But I realize that's not a common tool to utilize.

 

[LarryFine]

I might even try a plug-in filter on the washer.

 

[growler]

When the washer runs all the LED lights in house flicker.

Washer is on a dedicated 20 amp circuit.

Could try another load at the washer receptacle. Vaccume cleaner or maybe a heavy drill motor.

If you substitute another load that's equal to or more than the washer that should eliminate voltage drop if the lights don't flicker.

If it is voltage drop they just have to chase it down. Could switch the washer over to the other phase to start with.

 

[Jon456]

Another diagnostic test to try is to connect the washer to a different 20A circuit using a 12AWG extension cord.

 

[junkhound]

Wild guess...
Not saying it couldn't be a service issue, but with poco out several times not likely.
What about washer type? Variable speed driven with possible harmonic issues?

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Yep, that would be my guess. Washer a Neptune or similar with switched reluctance motor.
EMI interaction with LED power supplies, esp. if incancescent or 'old fashioed' fluorescents don't flicker.

Somebody already suggested an EMI filter on the washer.

Cost conscious member of our church replace a bunch of incandescent lamps with LED. Church has central Lutron dimmers. After about 6 months (ageing of LED power supplies?) all the LEDs started flicker.
Stuck a scope on the Lutron dimmers, fully on still had 15 degree off time, high dv/dt of dimmer turn on (even at '100%') interacted with LED supply. LEDs did not flicker on non-dimmer circuits, and yes, LEDs were rated for dimmers.
Switched reluctance motor drives in some high end washers generate a LOT of high dv/dt EMI. Most use a 3 phase bridge topology using IGBTs or FETs.

 

[Little Bill]

I had a similar problem a couple of years ago where the HO noticed lights in her kitchen and refrigerator flickering when she ran her washer. After investigating, I determined that it wasn't just the kitchen lights, it was all lights on one leg. Also found it wasn't necessarily caused by the washer itself, it was the load. I checked the panel and found there was a neutral problem and it was upstream of the panel. Had POCO come out since we aren't allowed to pull the meter. After determining it was also upstream of the meter, the lineman finally found a bad underground splice on the neutral.
I don't know if this would be the OP's problem, but it might be worth having POCO there while trying different loads on each leg to determine if it's a problem with connections on their end. I don't mean just having them come and take a quick look at their connections, I mean for them to check while loads are added in the house to create the symptoms.

 

[Jon456]

Another diagnostic test to try is to connect the washer to a different 20A circuit using a 12AWG extension cord.

With Little Bill's above post in mind, try plugging the washer (via an extension cord) into a circuit that's on the opposite leg than the leg used for the dedicated washer circuit.