Ferrite Choke questions

[NukeEngineer]

You're not following.... The interference is coming from the smart meter, going through the AC lines to the inverters. Nothing is radiating.

[bcroe]

That's what I was afraid of. I suspect everything is radiating, including the micro inverters themselves, so they have to be placed in a shielded enclosure, their wires run through toroids, but worse, the noise is probably back-feeding into/onto the panels themselves. Not sure what can be done about that.

The panel inputs can be filtered if that is what is needed. RF is slippery stuff, it doesn't follow nice
simple paths. Getting some real filters will produce better results. Bruce Roe

[DanKegel]

What's the system you're trying to protect from the RFI? How far is it from the system? And why do you suspect the smart meter?

Does a handheld broadcast FM radio pick up roughly the same RFI?

[sdold]

This sounds very odd to me. I thought smart meters only radiated, using internal antennas, in the ISM bands. I don't think they would be able to operate on lower frequencies on the power lines because I don't think it would make it past the service drop transformer. How did you measure the conducted RFI and what was the frequency that you saw? I'm not saying you're wrong, but I'm having a hard time understanding how it would work.

[Mike90250]

You're not following.... The interference is coming from the smart meter, going through the AC lines to the inverters. Nothing is radiating.

Generally, a smart meter uses a signal like Zig-Bee in the 2-5GHz band. I don't think it uses ac cable "carrier current" communication - cause that would stop at the transformer.

You (or a neighbor) may have some other gadget installed that uses carrier current (wireless intercom, X-10 home automation) and that's mucking up your inverter comms.

[NukeEngineer]

Generally, a smart meter uses a signal like Zig-Bee in the 2-5GHz band. I don't think it uses ac cable "carrier current" communication - cause that would stop at the transformer.

You (or a neighbor) may have some other gadget installed that uses carrier current (wireless intercom, X-10 home automation) and that's mucking up your inverter comms.

Nope, some use BPL which is carrier current. It's a strong enough signal to pass through the service transformer and reach the distribution substation, but not further.

See this link from ARRL and search for "BPL" http://www.arrl.org/smart-meters

[NukeEngineer]

Actually it's PLC, but could be BPL elsewhere. PLC is "power line carrier".

[NukeEngineer]

It seems that PLC operates under Part 15, so if they can't make the meter not interfere with my inverters' operation, then I can have them remove it...

[NukeEngineer]

https://www.youtube.com/watch?v=T2D9DEltOZM is a video of the AC line with these comms. And, yep, my lights flicker when the meter is talking.

[sdold]

According to that ARRL document, smart meter power line communication is rare or nonexistent in the U.S., so that wouldn't be on my short list of problems to fix. Have you actually measured a communications signal on the power line at the meter?

[NukeEngineer]

Yea, its not using BPL, its PLC. The meter manufacturer and SolarEdge are now collaborating on a fix. The meter manufacturer gave Enphase a filter algorithm for this exact issue, so SolarEdge will need to do so as well.

[Mike90250]

If the meter can broadcast enough power on the AC line to make lights flicker, that's just awesome !!

[jflorey2]

If the meter can broadcast enough power on the AC line to make lights flicker, that's just awesome !!

Well, if they are really shorting out the AC line with a triac, that would do it.

[bcroe]

Enough talk already. If its affecting your lights, it shouldn't be too hard to see the
nature of it on a scope. That in turn could lead directly to a fix. Bruce Roe

[NukeEngineer]

Enough talk already. If its affecting your lights, it shouldn't be too hard to see the
nature of it on a scope. That in turn could lead directly to a fix. Bruce Roe

No need, I linked a video to youtube with a scope showing the signal. Also, here's the patent on the communications method.

http://www.google.la/patents/US9294147

It's a Part 15 device, so if Alcara and SolarEdge can't get a filter algorithm for it, I can have it removed due to the interference it's causing.