Is there any industry information out there acknowledging the effect washing machines have on LED lighting?

J

JerryM

Member
Location
Port Orange FL
Occupation
Electrical Contractor
My company wires a lot of new homes and one out of every 20 or so will show flickering LEDs when the washing machine goes into agitate mode. We end up making multiple returns to "tighten" connections, or swap circuits around in the panel, almost always to no avail. This is on switched and dimmer circuits. It's difficult to tell a homeowner in his/her new home that it is their appliance causing the problem but I'm convinced that it is.
Recently, on a Reddit thread I read about one electrician using a small capacitor from Lutron--which is intended to augment the performance of their electronic dimmers--who discovered that it alleviated the flickering lights from the washer as well. We tried one yesterday and it did in fact work, but I'm not inclined to go through and install a bunch of these on those houses that have this issue, since it's nothing we've done wrong. What I'd like to have is some verified documentation, like an industry newsletter or something, that acknowledges this issue, so I can present it to these homeowners. I'm also curious if this is specific to one or two manufacturers.
Any help is greatly appreciated.
 
Welcome to the forum. Within the last week or so there has been about 5 similar experiences on this forum regarding washing machines and flickering LEDs.

The capacitor is probably helping filter out the noise in the waveform from the washing machine on the line. Or acting like a soft starter if the flicker is only when the motor is initially started up. I think oversizing the wire for the washing machine and lighting circuits should have a similar effect. Though I haven't tried it myself.

LEDs are sensitive to noise and the cheap ones don't have great filters. New machines use VFD which can ring out higher frequency waves on the 60Hz normal waveform. Usually referred to as harmonics but they don't necessarily need to repeat. It can also occur on motor start up / inrush where the current or voltage waveform is momentarily disturbed.

You can try and measure the voltage drop at the lights to see if the washing machine circuit is causing the voltage to drop enough to create the disturbance.

But if it is noise from the washing machine's VFD then you wouldn't necessarily see a voltage dip or waveform issues without a power monitor.
 
All those snake oil "home power factor correction" devices sold to unsuspecting homeowners by franchise electrical service companies in the past 20 years are finally seeing some use.😂
 
JerryM said:
... I'm not inclined to go through and install a bunch of these on those houses that have this issue, since it's nothing we've done wrong. ...
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Who specified the lights and appliances? The architect? You gave a bid to the contractor based on the architect's plans? Ask one of those people to pay for it, and include the cost on future bids.

It isn't about right or wrong in some moral sense, it's just about whose responsibility it is to pay for it. I agree it's not yours.
 
JerryM said:
It's difficult to tell a homeowner in his/her new home that it is their appliance causing the problem but I'm convinced that it is.
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No! Put the blame where it belongs- on the LEDs! Don't bother tightening connections, thinking about upsizing wiring or trying to get the POCO to increase their generating capacity. Don't blame the appliances.

By nature, incandescent and fluorescent lighting will not show power fluctuations unless they are very long. That's because the filament stays hot enough to ride through the dip and still produce light. Same with fluorescents, the phosphor continues to glow through the dip. But with LEDs the effect is almost instantaneous. No power, no light and they will react to the shortest dip that your eyes can discern.

So, unless you have an unusual voltage drop on your service blame the LEDs.

-Hal
 
Minimum Load Cap(acitor).

It apparently behaves like load resistors for car and motorcycle turn-signal LED replacements.

(Which are silly in my opinion; replace the flasher instead.)
 
Shaneyj said:
LUT MLC
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I was just going to post that. I've installed several of these. They add a small load to the circuit so that LEDs work better. They are mostly used when a dimmer is involved as the LED doesn't produce much of a load. For a while, Lutron was adding these in the package on certain devices.
 
It's a double hit with these consumer products. I think they need to turn up the heat in terms of proper design. High end washers use a VFD board. I work around high end industrial equipment and they return NONE OF THAT to the line! Good filtration and design.

However, stupid LED lights are no different. I've yet to see one that was designed right, with a real voltage regulated and filtered circuit. An LED should NOT change brightness with a change in input voltage. That indicates there is no regulator. All things LEDs do not like.
 
fastline said:
However, stupid LED lights are no different. I've yet to see one that was designed right, with a real voltage regulated and filtered circuit. An LED should NOT change brightness with a change in input voltage. That indicates there is no regulator. All things LEDs do not like.
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That is certainly possible with a "driver-in-a-box" design. But in the case of a driver located in the base of an "A" lamp, it's both a physical impossibility and an economic one. Also, how do you make them dimmable?

-Hal
 
10 and more years ago when leds used to flicker because of dimmer incompatibility a quick fix was to install an incandescent bulb after a dimmer.
Perhaps installing couple of incandescent bulbs around the house could help remedy the flickering leds
 
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