Solar panel inverter RFI

Hi, I have a solar panel inverter that is creating some RFI interference in the range of 15 - 20 kHz which affects my Time of Arrival lightning detector, which monitors lightning in those low freq areas, whilst the inverter is active. At night when the inverter goes to bed, the problem disappears, so 100% sure it is the inverter causing the issue. Not sure though whether it is the DC side or AC side. At the moment, there are no batteries in the system, after supplying the home, it feeds into the electricty grid. Any suggestions? I have had one possible solution forwarded, Schaffner in line filters from the FN2200 range.

Hello orion_jb2001 and welcome to the TechForum, we do have the Schaffner FN2200 line in catalog if you are interested in those.

Something worth looking into are the Ferrite Cores if your noise is low enough power for the inductors to eat it. I would match the diameter first before bothering with the specifics, if you’re lucky and a cheap passive could nock the noise below your time delay’s hysteresis or threshold for triggering.

Would love to see a picture of your setup!

Welcome to the forum.

If you can power the lightning detector from batteries, and the problem disappears when on batteries, then a low pass filter on the power input of the lightning detector should cure the problem.

If the problem still exists when running the detector on batteries then it could be very difficult to fix.

HI Michael, thanks for the reply. Fitting chokes, I have found I need powdered iron type is required. Micrometals mix 26 was recommended. Do these chokes need to sit flush on the cable and how many chokes would I need per line. The attached photo, two probes an E field on the top and H field in the enclosure on the bottom. E field a simple 100mm length of wire, measuring magnetic varition between the probe and the earth. The H field probe comprising 3 x 20 cm ferrite rods, placed in a trinangular form.

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Thanks for your reply, Paul, I shall have to try that battery option to see if that gives a lead to a solution. :slight_smile:

The Ferrite Cores from what I can see would be too small for that configuration. Shucks; might need a dedicated filter for that.

The battery idea is the most elegant should it work for you.