Radio frequency interference with recently installed solar panels

[Timmyscott]

I really appreciate all the effort and advice I’ve received. We went back to SolarEdge to ask more questions and to have their tech explain how he remotely tested the system. His reply is below. I still don’t understand it fully. Does this make sense? Do these tests show that it’s the panels themselves that are causing the interference?


“Again testing was as follows:
We first current throttled inverter 731A8262 (Larger inverter and array) which had no effect on your radio. When then did the same thing to 73118103 in which we heard your radio signal improve. At this point being that I left my optimizers communicating and sending full frequency I knew that the optimizers were not the issue (RFI) and it was current related (EMI). As you should have still had the issue without turning off the communication as in HAM radio as an example (RFI). We then took it a step further and let the larger inverter and array 7311A8262 generate at full capacity which would provide full broadcast signal and it had not effect on your radio. Only current throttling the optimizers to modules (solar panels) produced an EMI effect.

Again this can be resolve with an external antenna outside of the foot print of the array. The FCC would consider this to be the first reasonable step to take and has more than enough documentation on our product to know that we are not the cause. We take every claim serious and that is why we ran the initial testing as there can all ways be outliers. We knew going into this that this was an RF shielding/ absorption issue,” but I still needed to confirm.”

[sdold]

He's basically confirming that one of the arrays, its cabling or the inverter is emitting EMI. It's nice that it's not the communications between the optimizers and the inverter, but I don't think that matters. I think his suggestion to install an antenna "outside of the footprint of the array" isn't much of a fix unless you can take a portable radio to that location and confirm that there's no interference. And with an external antenna you'd need to connect it to whatever radios are having the problem. Re-radiating it with a small amplifier and antenna in the house could work, but you need enough signal isolation between the top antenna and the one in the house to not have feedback, but enough gain to make it work with all of the radios, it's tricky to set those up. I don't know what involvement the FCC would have, but I don't think they would expect you to try an outside antenna first. The line about it being an RF Shielding/absorbtion issue is meaningless unless it turns out to be radiation from the inverter itself (instead of cabling).

[bcroe]

That is just fine, it is their emissions and you are supposed to find a way to live with them.
The fact that one system is NOT causing a problem, shows that is in NOT inherent in the
design. I would go after the EMI radiating array, and localize the point of radiation. If it
is the other type inverter radiating and conducting along connections, you have some
options. One is get another inverter, maybe the same as the quiet one. Another is
contain the inverter EMI with a Faraday cage and filter leads.

I would certainly myself run each array to see how quiet each is by itself. Follow that
up by getting up close with your radio to locate the noise. Some trial filters might
tried for effect. A basketful of clamp on ferrite beads is probably not a cure, but might
give some hints of where to go.

AM interference is common, but me thinks it really is excessive to interfere with FM.
Bruce Roe

[Mike90250]

i suspect a bad optimizer, something like a cracked casing or a bad internal component. Having a Good array next to a bad one, makes troubleshooting very easy. Walk a radio around till you find the noisy component. Or a sheet of cardboard on a pole to shade each panel , find out which one has the bad optimizer.