[ketcham]

Does anyone use LED designed dimmer switches that do not emit radio frequencies?  My system is powered by an isolation transformer and dedicated lines, so the AC current has no pollution unless the Romex runs parallel and adjacent to each other, which is highly unlikely.  I now have long runs of balanced cable that I believe pick up their RF emission.  I currently use Lutron.  Are there other manufacturers with better results?

[Speedskater]

The LED lighting industry is rapidly developing. The next batch of a produce that mow works well might have problems.

The Ham radio operators are always writing about this problem:
http://lists.contesting.com/archives//html/RFI/

But I thought the Lutron was one of the good brands.

*************************
Go down to page 12 of this Jim Brown paper:
"Build Contesting Scores By Killing Receive Noise"
http://www.audiosystemsgroup.com/KillingReceiveNoise.pdf

[Wayner]

I use CL dimmers in my vinyl room to run the 3 par 30 LEDs in the ceiling with no ill effects at all. I do think the dimmers are Lutron.

[Atlplasma]

I used Lutron dimmers recommended by my lighting supplier and was quite disappointed in how well they worked. It was surprising considering they retailed for almost $90 each. (A good discounted price was in the $60 range.)

[FullRangeMan]

The reactors of fluorescent lamps and LED lamps emit a strong field of UV radiation that, besides being carcinogenic, interferes with electronic equipment.

[DaveC113]

IMO, you need to keep LED dimmers out of the house until they manage to correct their deficiencies.

[Wayner]

I used Lutron dimmers recommended by my lighting supplier and was quite disappointed in how well they worked. It was surprising considering they retailed for almost $90 each. (A good discounted price was in the $60 range.)

You got taken. I bought mine at ACE Hardware for about $25 each. They work very well. No noise, and I can dim the lamps down to a glow.

[Wayner]

The reactors of fluorescent lamps and LED lamps emit a strong field of UV radiation that, besides being carcinogenic, interferes with electronic equipment.

So is standing out in the sun.....so what is your point? So does HID lamps, your computer screen, tanning booths, etc, etc..........

[FullRangeMan]

So is standing out in the sun.....so what is your point? So does HID lamps, your computer screen, tanning booths, etc, etc..........

Iam using halogen lamps, at least dont emit UV.

[Atlplasma]

You got taken. I bought mine at ACE Hardware for about $25 each. They work very well. No noise, and I can dim the lamps down to a glow.

Well, maybe. The three-way switches were more expensive for sure. Aesthetics also mattered. 

[ketcham]

I appreciate everyone contributing.  The story gets even more mysterious:

There is a hot line that leads to and powers three switches in one box, two outer ones are dimmers.  All three run a different bank of lights.  I replaced one dimmer switch with a regular switch.  The remaining dimmer runs the uplights on the beams.  The middle bank switch is not a dimmer and has no effect on buzzing whether on or off.  However where I replaced the dimmer with a regular switch: If that circuit is 'on' the dimmer switch when turned on has no noise.  When off, the dimmer switch circuit has noise when it is on.  Weird.  When replace that last switch with old non LED designed switch.  No noise.  So now there is two standard switches and one old dimmer Lutron that is non-digital and designed as a manual toggle with an on/off switch at the top (or bottom-orientation dependent).


Lutron MAESTRO MACL-153M - they cycle at 120 Hz which is the noise. 

[Rusty Jefferson]

This is something I've been wondering about.  Whether these dimmers actually reduce/eliminate buzzing from the bulbs. I don't have LED in my listening area, but do have them in the house.  The biggest problem I've had is having to turn them off to use my FM tuner.  The interference is ridiculous.

Does not using a CL dimmer reduce bulb life?

[mcgsxr]

Odd.  I use Lutron LED dimmers with my LED capable pot lights filled with PAR20 LED bulbs in several places in my house.

No buzzing or interference of any kind.

The only place I have an issue is with a standard dimmer (was installed prior to the LED fixture) in the eat in part of the kitchen.  Those MR16 (I think that is the designation) bulbs buzz audibly with the old dimmer.  I should replace it with a standard switch since we never dim those lights anyway.

[Wayner]

This is something I've been wondering about.  Whether these dimmers actually reduce/eliminate buzzing from the bulbs. I don't have LED in my listening area, but do have them in the house.  The biggest problem I've had is having to turn them off to use my FM tuner.  The interference is ridiculous.

Does not using a CL dimmer reduce bulb life?

No, they were designed with LED lighting in mind. Older dimmers may be hard on bulb life.......

[Atlplasma]

Different strategies are used in dimmers to control light levels. This Lutron page provides some descriptions: http://www.lutron.com/en-US/Education-Training/Pages/LCE/DimmingBasics.aspx

[jea48]

I have several dimmers all over my house. The ones used on the home automation system are Leviton. Others that are not part of the home automation system are Lutron.

The majority of the lighting is still incandescent BR30 65 watt 130V lamps. Do those dimmer loads radiate/emit RFI through the air and onto other near by branch circuit wiring? You bet it does. Through the air at least 4 to 5ft until it starts to dissipate.

Just recently I installed LED, 85 watt equivalent incandescent, lamps in the can lights in the kitchen. I installed a Lutron 3way dimmer to dim the lights down as needed.

With a total of 7 dimmers for incandescent and one LED I can not detect any change in my 2 channel audio system or my HT system whether the dimmers are on or off.
With one exception. I have a separate audio rack in my audio room, with some old vintage 1970s equipment setting on it that is about 3ft from a Lutron dimmer. Even though the branch circuit the equipment is plugged into is different than the lighting circuit, the equipment is within the radiated RFI field of the dimmer as well the branch circuit the equipment is plugged into. The branch circuit wiring feeding the audio equipment is also infected by the Dimmer RFI.

 When listening to a, vinyl record, CD, or Cassette tape, I do not hear any noise. It is quite noticeable if the tuner is used on the Marantz 2252B receiver though. Especially the AM band. LOL though, who listens to AM radio anymore?

IF you have dimmers in your home here is what you need to do when installing a new dedicated branch circuit/s for your audio system or HT system. KEEP the new dedicated branch circuit wiring as far as possible from any dimmer branch circuit wiring. Especially the load side wiring of the dimmer that feeds the lighting loads.

As for the line side feeding the dimmer I have found the dimmer RFI starts to dissipate the further you get away from the dimmer going toward the source, the electrical panel, the branch circuit is fed from. Is it still at the electrical panel? Yes somewhat but a whole lot weaker. And I found even weaker yet the farther you get away from the breaker/s feeding the lighting circuits the dimmer/s are fed from.

For my 2 channel audio system I kept the two 10-2 with ground NM-B cables, (Romex is a trade name of NM cable), as far away from parallel lighting branch circuits as possible as soon as I could after getting out of the electrical panel. I also kept the two dedicated circuits separated from one another by at least 2ft. The length of the dedicated branch circuits are about 75ft from the electrical panel to the wall duplex receptacle outlets. At the receptacles I can not detect any discernible dimmer RFI noise. The audio system is dead quiet.

IF it is not possible to keep a new audio dedicated circuit away from existing lighting circuits that have dimmers then you could use MC aluminum armor cable. The armor should/will shield the dedicated branch circuit wiring from the outside radiated dimmer RFI.

//

I ran across this Lutron article doing a web search.


Minimizing Radio Frequency Interference (RFI)
Application Note #519
Revision D
June 2014

    A solid-state dimmer is an electronic switch that rapidly turns the current on and off 120 times per second to achieve the dimming effect.  This rapid current switching may cause radio frequency interference (RFI) — an audible buzzing noise — with sensitive audio and radio equipment. Although every Lutron® dimmer contains a filter to suppress RFI, applications with sensitive equipment may require additional filtering. Typical examples of RFI sensitive equipment are AM radios, stereo sound systems, broadcasting equipment, intercom systems, public address systems and wireless telephones. RFI can be transmitted in two ways:
•     Radiated
•     Conducted

 Radiated RFI
    All wiring that carries dimmer-controlled current can act as an antenna to radiate RFI into the air waves. Any sensitive equipment that is in close proximity to this wiring can pick up the RFI and generate noise into its system. Also, this could occur if the wiring for sensitive equipment runs along side the wiring for the dimmer.
[/i]
https://www.lutron.com/TechnicalDocumentLibrary/360484.pdf

//

Check out this interesting video on dimmer RFI harmonics.
https://www.youtube.com/watch?v=OCK5W9vlAE0


 

[ketcham]

Excellent input and I certainly appreciate the links.  Doing some research on my end.  I will post some results when done.

Thank you!

[ketcham]

I wanted to let everyone know to avoid these dimmers as the RF may interfere with your system:


Avoid the Lutron MAESTRO  MACL-153M




These work well:  Perhaps a different manufacturer or different design.  They do not inject noise into my AC or RF emissions.  If they do by design, the emissions are not noticeable.  There is an internal switch that allows you to select LED/Incandescent or CFL.  I have LED and they work really well.  No noise.