Stop EMI / RFI Interference in Off Grid Solar PV Systems

Its easy to make a common mode choke for this application. I used a ferrite core and wound as many turns as possible through it.

The core to use is the Fair-Rite Toroid Core FT240-31. like the one shown on the right (Yes I am an Amazon Affiliate). Again, making the common mode choke is not critical – other than the ferrite core material needs to be type 31. Using this type should attenuate EMI up to 400 mHz. If you are interested in the specifications of Fair-Rite’s 31 material, you can view the specifications here. Then I put it between my solar panel and the solar charge controller. Next I put a 0.1 uF capacitor from the negative side of the charge controller that was labeled¬†Solar to earth ground.

 

Here is a photo showing the coil and the capacitor installed on my Windy Nation charge controller.

EMI Filter that stops interference on my off grid solar PV system

EMI Filter that stops interference on my off grid solar PV system