Relay Switch 2x1,5kW and Dimmer

[plutonium 5]

Hi,

 

is it normal to hear buzzing noise from devices mentioned in Title even if they are completely off.

 

Switch is connected only on power, without load on other side and it produces some noise inside. Same thing with dimmer.

 

Does someone have any explanation or this is normal?

 

Kind regards

[XanderF 8]

Never heard any buzzing noise coming from a relay switch, but dimmers do make some noise even if the light is off. Probably because Fibaro uses triac. The Qubino dimmers (mosfet) I use don't make any noise.

[petergebruers 1,268]

I think it's normal. At the moment, I have to put my ear against the box (where it's mounted) and I can hear a slight hum. On occasions, when the 230V is polluted (you need a scope to test that hypothesis) - some LED start producing more hum. 50 Hz is everywhere!

[plutonium 5]

What about relay switch module? With dimmer it is fine to hear something, but with relay??

[petergebruers 1,268]

Sorry I wasn't more precise... I checked FGD211 Dimmer and is almost silent when not active, but does hum under load. I also checked the FGS221 Double Relay Switch and it always produces a very faint hum.

[j.nowacki 5]

As @petergebruers said it can be thing of grid itself when it comes to Relay Switch, with Dimmer the load characteristic is also important.