-->
Page 4 of 5

Re: External Interference from a Electromechanical Contactor

PostPosted: Tue Sep 13, 2016 8:28 am
by Awacks
It's a Siemens 3TF41 (http://www.datasheetspdf.com/PDF/3TF41/943807/1), but the contactor is just an input, a different circuit is triggering the contactor.

It may be of no use, but things improved a little bit once again, I'll look into optocouplers to isolate the contactor coil from the ESP input, because it still randomly triggering some of the buttons (that are taken care at a software level for now).

But what should be done regarding the spikes of voltage / EMI from those motors starting/stopping all over my power grid ?

Re: External Interference from a Electromechanical Contactor

PostPosted: Tue Sep 13, 2016 9:25 am
by sborden
You have the capacitor on the wrong side of the switch. It should be pulling down the IO pin directly.

Re: External Interference from a Electromechanical Contactor

PostPosted: Tue Sep 13, 2016 9:25 am
by rudy
The data on the contactor is unimportant. It could be causing spikes every time it is turned off but you would need to deal with that at the coil end and it does not seem that you are an electrician (unlicensed) so don't go there. But as a side note, the snubbers you have looked at, when used, they would be placed across the coil.

You have not described (or I missed it) what is powering your project. So all I can recommend is putting a line filter in series with your power supply. Maybe look into getting a better power supply that won't pass through disruptions in the power.

An additional note. A lot of interference issues are caused when equipment is turned off.

Re: External Interference from a Electromechanical Contactor

PostPosted: Tue Sep 13, 2016 12:53 pm
by Awacks
It's powered by a standard 110v-220v to 9v switching power supply (https://www.adafruit.com/product/63) and a breadboard psu (http://www.sivava.com/k07-ywrobot-3-3v- ... board.html). There's a picture of the pcb on page 2.

The main reason is to power the LCD (5V), if not for that, I would just power the ESP with the micro USB cable.

I've just purchased the optocoupler and will look into LC filters.