Good earth LED (under cabinet). Can’t stop the buzzing

[Kimura]

Installed Good Earth LED under cabinet lighting for a customer. On a standard single pole , there is no buzzing.


Customer requested a dimmer. I have tried various Lutron (CL, Diva) to no avail. I have also tried Leviton products.


For fun I tried a Kasa smart dimmer , same result. Buzzing. I’m at a loss. No other lights on this switch

 

[LarryFine]

LED lights and driver (power supply) must be rated to be dimmable.

 

[Kimura]

LED lights and driver (power supply) must be rated to be dimmable.

Per manufacturer they are dimmable with forward phase dimmer.

 

[LarryFine]

Per manufacturer they are dimmable with forward phase dimmer.

Next step: most LED makers have a list of compatible dimmers.

 

[Kimura]

Next step: most LED makers have a list of compatible dimmers.

Hi Larry. Yes the CL and DIVA dinners are on the compatibility list. Compatibility to Leviton means you can’t hear a buzz from 2ft away supposedly ?.

I can hear three from 20 ft away

 

[LarryFine]

I can hear three from 20 ft away

What is buzzing, the dimmers or the drivers? Are the drivers magnetic or electronic?

I have found that the Ariadni line of dimmers works and plays well with others.

I use that line with GM Lighting dimmable magnetic drivers; I've never heard a buzz.

 

[Kimura]

What is buzzing, the dimmers or the drivers? Are the drivers magnetic or electronic?

I have found that the Ariadni line of dimmers works and plays well with others.

I use that line with GM Lighting dimmable magnetic drivers; I've never heard a buzz.

The drivers are buzzing and they are electronic. Thanks for the recommendation on Ariadni. Will check them out

 

[LarryFine]

The drivers are buzzing and they are electronic. Thanks for the recommendation on Ariadni. Will check them out

The correct dimmer for magnetic vs electronic drivers may not be the same. Be sure to confirm.

 

[Adhood]

Installed Good Earth LED under cabinet lighting for a customer. On a standard single pole , there is no buzzing.


Customer requested a dimmer. I have tried various Lutron (CL, Diva) to no avail. I have also tried Leviton products.


For fun I tried a Kasa smart dimmer , same result. Buzzing. I’m at a loss. No other lights on this switch

I'm having the same issue. Did you ever find a dimmer switch that would not hum?

 

[Dennis Alwon]

I'm having the same issue. Did you ever find a dimmer switch that would not hum?

It often is not the dimmer that is humming but the bulbs. Customers thought I was nuts until I showed them where the sound was coming. Change to a different bulb often stops it

Kimura you sometimes need an ELV dimmer... That is an electronic Low voltage dimmer. Halo undercabinet lights used to require that.

 

[LarryFine]

The LED maker should have a list of compatible dimmers.

 

[Adhood]

It often is not the dimmer that is humming but the bulbs. Customers thought I was nuts until I showed them where the sound was coming. Change to a different bulb often stops it

Kimura you sometimes need an ELV dimmer... That is an electronic Low voltage dimmer. Halo undercabinet lights used to require that.

Yeah it's definitely the fixture. Unfortunately these don't have changeable bulbs they have integrated strip LED lights. It's weird because I have 2 18" ones and 2 12" ones and it's only the 12" that are humming. They are all the Good Earth under cabinet lights mentioned at the beginning of this post.

 

[Dennis Alwon]

I would try the pricey electronic dimmers

 

[Adhood]

I would try the pricey electronic dimmers

The ELV dimmer below brought the humming to an almost imperceptible level. Literally have to put my ear on the fixture to hear a small hum.

Thanks all!!

Lutron Diva Dimmer Switch for Electronic Low Voltage, 300-Watt/Single-Pole, White (DVELV-300PH-WH) DVELV-300PH-WH - The Home Depot

The Lutron Diva dimmer switch is a simple and elegant solution designed to match your existing designer opening switches and accessories. This Diva dimmer switch is for use in 300-Watt electronic Low-Voltage

www.homedepot.com

 

[synchro]

The ELV dimmer below brought the humming to an almost imperceptible level. Literally have to put my ear on the fixture to hear a small hum.

I suspect that the fast rising output voltage from the forward phase control dimmers you initially tried was causing current spikes through the capacitors in the drivers of the LED fixtures.
The buzzing may have been caused by the magnetic fields from the current spikes or from the capacitors themselves.
Some capacitors, especially ceramic types, have piezoelectric properties and so they may make noise that's noticeable when driven with pulses, etc. :
https://product.tdk.com/en/contact/faq/31_singing_capacitors_piezoelectric_effect.pdf

An ELV dimmer instead turns ON at zero crossings of the AC voltage and the rate of change of the voltage there is limited, and so there are no large current spikes. The dimmer's internal MOSFET device turns off at various times within the AC cycle to modulate the dimmer's average output. But that sudden turn-off would cause large voltage spikes on a magnetic transformer or ballast and so ELV dimmers would not be suitable for those applications.