Solar Panel Installation On The Roof Of My Home

RFI / EMI From Solar

While researching various micro-inverters, I discovered there were concerns about RFI / EMI interference with them. Since I am also an Amateur Radio operator, this was certainly a concern for me. My solar system has 12 Enphase micro-inverters, so when I had them installed, I had the installer follow the guidelines in the Enphase Installers Troubleshooting guide. Specifically pages 22 & 23. Here is the pertinent diagram from Enphase’s troubleshooting guide:

Reduce EMI / RFI of Enphase Microinverters With Ferrites

Points of interest from the installer’s guide:

• Install a PV subpanel to land all the solar branch circuits.
• Install a dedicated outlet for the Envoy (and power line communication bridges, if needed) off the subpanel.
• Filter the phase conductors running from the subpanel back to the load center.
• Ferrite toroids are an effective, simple filtering mechanism.

The ferrite toroids that Enphase recommends can be purchased from DigiKey. The ferrite is made be Epcos and the part number is B64290l0082X087. Here is the link for the ferrite.

UPDATE:

Enphase added an EMI ferrite noise filter to the output of their microinverters. With this addition, the EMI ferrite core filter mentioned below is no longer necessary. I have kept the following two paragraphs in this post for reference – Mike

Additionally, I added an EMI ferrite noise core filter on the output of each Enphase micro-inverter. Here is a photo of  the Ferrite Core attached to the output of the Enphase micro-inverter. Its the gray thing on the right side. Its  clipped as close to the micro-inverter as possible. I also added a cable tie around the ferrite core, as the holding tabs on the ferrite core just barely snapped shut. This was extra insurance that the ferrite cores would stay on the Enphase micro-inverter.

This is something that I came up with, as it seemed to make sense to do this. Here is a link for the EMI RFI Noise Ferrite Core Filter for 7mm Cable that I used. As far as interference to my ham radio, my lowband antennas (80 – 10 meters) are 25 ft. away from the Enphase inverters with no noise problems. My 2 Meter radio is 30 feet away. I also have no noise issue there either.