4 foot LED lights flickering

[Nigel Goodwin]

You must not be a good guesser, as both are wrong.

Problem still exists, possibly you did not read the results in post 11, no further experiments proposed or items to check with the instruments I have, and the thread got side tracked talking about the various types of 4 foot LED lights.

Not 'side tracked', your issue is most likely that you're using unsuitable lights - which aren't regulated, so they flicker as your mains varies. However, while using better lights should cure your symptoms, the main issue is probably why your mains is varying just from a washing machine?.

My house has very old incoming electricity cables, so far thinner than modern requirements - I think they are only 6mm?, modern requirements are 10mm? - so when the shower is turned on the lights in the master bedroom (which are dimmable LED's on a dimmer) dim CONSIDERABLY. I think this is exaggerated by the LED bulbs been too big really, so they run at a pretty low dimmer level in normal use.

None of the other lights in the house, all of which are regulated LED bulbs and tubes, are affected at all. Many of the bulbs are Philips Hue controlled by Alexa, and I've been considering altering the master bedroom lights as well.

 

[Kart31]

Not 'side tracked', your issue is most likely that you're using unsuitable lights - which aren't regulated, so they flicker as your mains varies. However, while using better lights should cure your symptoms, the main issue is probably why your mains is varying just from a washing machine?.

Would this voltage variation show up on a DVM, because I'm not seeing it. My question would be why the new washing machine and not old one?

My house has very old incoming electricity cables, so far thinner than modern requirements - I think they are only 6mm?, modern requirements are 10mm? - so when the shower is turned on the lights in the master bedroom (which are dimmable LED's on a dimmer) dim CONSIDERABLY. I think this is exaggerated by the LED bulbs been too big really, so they run at a pretty low dimmer level in normal use.

By flicker, I mean quickly change brightness repeatedly (bright-dim-bright) while the machine is running. Not to say the lights are bright, machine turns on lights go dim, then machine turns off and lights are bright again.

All the wiring in my house is up to date. The incoming triplex and panel are only 5 years old and all bramch circuit wiring is 12g copper NM-B. I ran an extension cord (OK not the best, but I didn't want to take down the light) and tried them one light several other circuits with the same result.

 

[rjenkinsgb]

My guess would be that the washing machine is using some form of phase control and spiking or otherwise upsetting the mains power waveform, which in turn upsets the lamp power units.

Try adding a capacitive main filter or "Class X" capacitor at the washer location and see if that has any effect?

 

[Nigel Goodwin]

Would this voltage variation show up on a DVM, because I'm not seeing it. My question would be why the new washing machine and not old one?

Unlikely, digital meters are useless for things like that - and I doubt you're see it on an analogue one either.

By flicker, I mean quickly change brightness repeatedly (bright-dim-bright) while the machine is running. Not to say the lights are bright, machine turns on lights go dim, then machine turns off and lights are bright again.

If they are going dim, and staying dim, I would expect you to be more likely to be able to measure the change with a digital meter - as it's fairly constant

All the wiring in my house is up to date. The incoming triplex and panel are only 5 years old and all bramch circuit wiring is 12g copper NM-B. I ran an extension cord (OK not the best, but I didn't want to take down the light) and tried them one light several other circuits with the same result.

 

[gophert]

The LED lamp you have is very inexpensive construction snd appears to be a long series connected row of LEDs for the positive phase and a long series for the negative phase (second row) and one resistor, no control circuitry. Once the line voltage exceeds the forward voltage, you'll see the brief flash. Both rows together, will be 120Hz in USA so your eye won't pick it up. The cycles on the washer /agitator will likely cause very slight brown out every time the motor changes direction snd the peaks of the phase will drop slightly which ends up being a lot when the lamp is only on near the peak of each phase. I'm guessing each lamp has 50 to 60 LEDs for each row to create a forward voltage of about 160 volts. That leaves only about 8 volts of peak where the LED is on each cycle. If your AC power sags to from 168 (normal peak) to 164v peaks, your LEDs will draw half of the current vs the 168V peak. The drop to 164V will only be for a fraction of a second as the load in the washer is at maximum as the agitator or basket changes direction. Your meter will likely not detect it.

Take the lamp apart and confirm whether the LEDs are all in series (and how many in each strip) and what kind of control system in in the lamp. I'm guessing it is simply one current limiting resistor.

 

[Kart31]

Try adding a capacitive main filter or "Class X" capacitor at the washer location and see if that has any effect?

Can you elaborate on this please. I have only used capacitors on AC for their impedence , reduce voltage without generating a freighter load (more than a boat load) of heat.

 

[Nigel Goodwin]

Can you elaborate on this please. I have only used capacitors on AC for their impedence , reduce voltage without generating a freighter load (more than a boat load) of heat.

The washing machine should have internal filtering anyway - something like this:

Mains Input Filters – What is Inside the Box and Why? | Interference Technology

J M Woodgate BSc(Eng) C.Eng MIET SMIEEE FAES HonFInstSCE J M Woodgate and Associates jmw@jmwa.demon.co.uk www.jmwa.demon.co.uk These days, it’s common practice to buy-in mains input filters in the shape of metal boxes with four or five terminals. The supplier’s […]

interferencetechnology.com

 

[shortbus=]

The LED lamp you have is very inexpensive construction

There you go again. Giving him answers he doesn't want to hear.

 

[rjenkinsgb]

Can you elaborate on this please. I have only used capacitors on AC for their impedence , reduce voltage without generating a freighter load (more than a boat load) of heat.

A capacitor (of a suitable type and rating) connected across the AC power will reduce the level of any electrical noise spikes or pulses that could be affecting the AC waveform.

More info here:

Filter capacitor | Applications | Capacitor Guide

Filter capacitors Capacitors are reactive elements, which make them suitable for use in analog electronic filters. The reason for this is that the impedance of a capacitor is a function of…

eepower.com

I can't say as a fact that is the problem / solution, but I have experienced similar things a few times over the years, with one piece of equipment creating noise spikes that upset something else.

 

[Kart31]

I can't say as a fact that is the problem / solution, but I have experienced similar things a few times over the years, with one piece of equipment creating noise spikes that upset something else.

Reminds me of a story from my tech professor, where there was a problem with something they were building. One day they were quitely watching it run, then there was a audible click and the system screwed up. The click was from a contactor for the HVAC unit overhead. They reset the system. Moved it three feet (changed nothing else but the location). Then waited for the HVAC unit to cycle again. When it did, the problem did not happen. "one piece of equipment creating noise spikes that upset something else." in this case radiated instead of transmitted. But the idea is the same.

A capacitor (of a suitable type and rating) connected across the AC power will reduce the level of any electrical noise spikes or pulses that could be affecting the AC waveform.

If I place the cap in the light or elsewhere as the system stands, I might as well place the cap on the 200A incoming mains. Would a cap on the load side of an isolation transformer help to contain "fixing the problem". It would be possible to 'isolate' either the lights or the washing machine. I would think the washing machine would be the better one to isolate in this method as it is believed to be the source. I would need a 2.4KVA transformer. But what size cap? Without a scope is it possible to determine the frequency of the noise?

 

[rjenkinsgb]

I'd try it directly at one of the lights first.
The cable length from the washing machine provides some impedance, so allows more noise attenuation for a given value of capacitor.

You do not need a transformer, just filtering?
Try a 0.1uF or higher X type capacitor; or one from a scrap fluorescent light fixture, a non-electronic one should have a fairly large AC rated cap straight across the AC supply for power factor correction, which should also do the job.

If the added cap works, adding a proper LC power filter at the washing machine (as Nigel notes it should have) would not hurt, as it should stop the noise at the source.

The lights should really also have filtering fitted as standard though, so they are not affected by moderate levels of power noise.

 

[gophert]

I'd try it directly at one of the lights first.
The cable length from the washing machine provides some impedance, so allows more noise attenuation for a given value of capacitor.

You do not need a transformer, just filtering?
Try a 0.1uF or higher X type capacitor; or one from a scrap fluorescent light fixture, a non-electronic one should have a fairly large AC rated cap straight across the AC supply for power factor correction, which should also do the job.

If the added cap works, adding a proper LC power filter at the washing machine (as Nigel notes it should have) would not hurt, as it should stop the noise at the source.

The lights should really also have filtering fitted as standard though, so they are not affected by moderate levels of power noise.

The problem is not big enough for him to try anything, he hasn't given any detail about the LEDs (single series, antiparallel series, on-board power supply. When the washing machine was questioned, he suddenly added that it was brand new. He is just trolling to have the "joy" of turning down suggestions.

 

[Kart31]

I'd try it directly at one of the lights first.
The cable length from the washing machine provides some impedance, so allows more noise attenuation for a given value of capacitor.

Rhetorical question mostly, but how much impedance does 10-12 gauge wire really offer.

You do not need a transformer, just filtering?

I was just thinking that it would isolate the filtering to the unit rather than trying to filter the whole house.

Try a 0.1uF or higher X type capacitor; or one from a scrap fluorescent light fixture, a non-electronic one should have a fairly large AC rated cap straight across the AC supply for power factor correction, which should also do the job.

The fixtures themselves were torn around and sent off with the scrap metal. Scrap flourescent fixture electronics I have. LOL. I will see what goodies they provide.

 

[Kart31]

Update: The electronics were able to provide a 4nF, 33nF, .05uF, 0.1uF, and 0.15F 250V capacitors. My initial attempt was to take apart the light and add the cap at the incoming leads. Little twerps that made the lights ultrasonically welded it all together. I was able to remove the AC cord strain relief to get a little peak inside. I noted a couple of ICs, some surface mount caps or resistors, a polarized cap and another component (maybe a round dipped cap of some sort).

With the ends off two old extension cords, I made a suicide cable (I see why they call it that now-it was a very harrowing setup) and added the cap between the two ends from hot to neutral. I tried each of the three uF caps one at a time. No change in the flickering. I think I need to ask around for a scope.

 

[Kart31]

In an ad today I saw an item that may be worth trying.

Appropriately sized of course.

Few questions:
1. Would this work if I put it at the lights?
2. Would this work at the washing machine and keep this noise there? Thus I would not have to install a bunch of these, but just one (appriately sized of course)

 

[JimB]

Would this work if I put it at the lights?

Yes,
IF the problem with the lights really is due to noise conducted along the power wiring.

Would this work at the washing machine and keep this noise there?

Yes,
BUT, be aware that the filter is rated at 6 Amps, a washing machine with the water heater turned on will probably take more that 6 Amps, thus overloading the filter.

JimB

 

[Kart31]

BUT, be aware that the filter is rated at 6 Amps, a washing machine with the water heater turned on will probably take more that 6 Amps, thus overloading the

Thus I would not have to install a bunch of these, but just one (appriately sized of course)

Hence I noticed it was only 6A. In the US, washing machines are to be on a single outlet 20A circuit by code. I would need to seek a 20A version. Which I'm willing to dump the money into if it has a better than good chance of working.

Honest question though. "washing machine with the water heater turned on" I have not heard of a washing machine with a built in water heater...in the US...do they in Europe? More than possible since most if Europe is on 240V (IIRC, instead of us whimpy Americans on 120V)

 

[Nigel Goodwin]

Hence I noticed it was only 6A. In the US, washing machines are to be on a single outlet 20A circuit by code. I would need to seek a 20A version. Which I'm willing to dump the money into if it has a better than good chance of working.

Honest question though. "washing machine with the water heater turned on" I have not heard of a washing machine with a built in water heater...in the US...do they in Europe? More than possible since most if Europe is on 240V (IIRC, instead of us whimpy Americans on 120V)

Yes, all washing machines here have water heaters - as modern washing machines use very little water, all it would get is cold water out of the pipe coming in anyway, and the fairly universal use of combi boilers makes it even more so. The VERY few (two or three?) American washing machines I've seen have all had water heaters in as well - it should be obvious from the thickness of the mains lead. Back many decades ago washing machines had both hot and cold fill (which is exceedingly rare now) but still had heaters - as you couldn't guarantee a hot water supply - if there was only a cold feed, then you put a Y splitter on the incoming supply

Europe incidentally uses nominal 230V mains - which in practice means 240V in the UK, and 220V elsewhere - the 230V spec is for manufacturers to use, as the tolerances required cover both 220 and 240.

 

[Kart31]

Yes, all washing machines here have water heaters - as modern washing machines use very little water, all it would get is cold water out of the pipe coming in anyway, and the fairly universal use of combi boilers makes it even more so. The VERY few (two or three?) American washing machines I've seen have all had water heaters in as well - it should be obvious from the thickness of the mains lead. Back many decades ago washing machines had both hot and cold fill (which is exceedingly rare now) but still had heaters - as you couldn't guarantee a hot water supply - if there was only a cold feed, then you put a Y splitter on the incoming supply

US still has hot and cold fill. I would expect an American made machine sold in Europe to follow the norm of European manufacturers selling in Europe (to have a hot water heater included). As the US runs from 120V 20A service, there's not a lot of room (wattage) left to run the motor and a hot water heater. I can see several converging factors driving the difference. Thanks.

P.S. American laundry detergent manufacturers are formulating for using cold water only. Wouldn't be surprised if some penny pinching manufacturer decided to pitch a cold-water only model at some point.

 

[Nigel Goodwin]

US still has hot and cold fill. I would expect an American made machine sold in Europe to follow the norm of European manufacturers selling in Europe (to have a hot water heater included).

I wasn't talking about American manufacturers products sold over here, but people who had (rather stupidly) brought their American appliances when they moved over here. As far as I'm aware they 'may' have been 220V models, as the larger machines probably are?.