For those who would like to know what are the
conducted and radiated RFI limits in the EU and
U.S., this report (beginning on p. 11) provides
a nice summary:
https://www.intertek.com/uploadedFiles/Intertek/Divisions/Commercial_and_Electrical/Media/PDF/EMC_Testing/EMC-Compliance-for-Renewable-Resource-Power-Systems.pdf
Note that the FCC Part 15, Class B standard does not specify maximum
conducted emissions on the DC power port nor the "telecommunications"
port (i.e. control/network interface) of an inverter (or battery charge
controller, for that matter), whereas the EU residential standard does have such
limits. The conducted emissions standard on the AC (grid-tied) port
of an inverter is set by UL 1741 in the U.S., which in turn cites IEEE 1547 as
its
basis. The absence of a standard for conducted RF emissions on the DC port
of an inverter may explain why some central inverter designs are RF-noisy -
they connect to the "antenna" comprising the PV module DC interconnect wiring.
If the Enphase microinverters meet the EU residential standards for conducted
emissions on all ports, they are less likely to excite the (AC) interconnect
wiring at
levels that cause RFI at distances greater than 10 meters from the PV
installation.
Mike, K8CN
________________________________
From: RFI <rfi-bounces+mike.carter=unh.edu@contesting.com> on behalf of Carter,
Michael <Mike.Carter@unh.edu>
Sent: Sunday, May 23, 2021 8:28 PM
To: RFI List <rfi@contesting.com>
Cc: Frank <kibbish@gmail.com>
Subject: Re: [RFI] SOLAR INSTALLATION PROS/CONS
Caution - External Email
I did not mean to imply that microinverter designs
are fundamentally bad nor that central inverter
designs are RFI-free - as others have noted, the
Enphase microinverters are seemingly RF quiet,
and there are central inverters with poor RFI
characteristics. I should have listed the 4th
point of my post first - check similar installations
for RFI on all bands of interest before entering into
a purchase contract. The key issue is whether the
inverter design itself suppresses both radiated and conducted
RFI across the frequency range of interest.
Frank, N6OI's point about the more stringent EU
standards for RFI from electronic devices,
including power inverters, is spot on.
Mike, K8CN
________________________________
From: RFI <rfi-bounces+mike.carter=unh.edu@contesting.com> on behalf of Dan
K2YWE <dan.k2ywe@gmail.com>
Sent: Sunday, May 23, 2021 6:43 PM
To: Frank <kibbish@gmail.com>
Cc: RFI <rfi@contesting.com>
Subject: Re: [RFI] SOLAR INSTALLATION PROS/CONS
Caution - External Email
This article linked below does not address RFI directly, but I found it
illuminating as I had not heard of Enpahse before.
I designed both centralized and distributed switching power conditioners
for a good part of my career. They powered sensitive receivers and had
ultra-low conducted and radiated noise requirements. I can tell you that we
jumped into resonant inverter topologies very quickly early on and used
them in distributed systems. Vicor was one of the first companies to patent
and sell a particularly quiet implementation of a basic resonant inverter
module. I assume that by now there are several manufacturers that are
making good quiet ones. Perhaps Enphase is one of them.
https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.mcelectrical.com.au%2Fmicro-inverters%2F&data=04%7C01%7Cmike.carter%40unh.edu%7Cbe30e58d34904d7439d308d91e4adf92%7Cd6241893512d46dc8d2bbe47e25f5666%7C0%7C0%7C637574129195724674%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=cHbXTffjBaCDaUZEggcT2fAOkPr959bQ6ZUeg%2Fae9%2FA%3D&reserved=0
73, Dan
On Sun, May 23, 2021 at 6:33 PM Frank <kibbish@gmail.com> wrote:
> The systems engineer at the installation company I used did some research
> of his own once I reached out to him, and he said he found more reports of
> RFI with single inverter systems than with individual microinverters on
> each panel. And I found some reports on my own that seemed to support
> that.
>
> But then I also reached out to the ARRL RFI lab to see what they knew. I
> received a reply from Mike Gruber, W1MG, EMC Engineer at ARRL HQ, who said
> that they had received multiple reports of RFI from systems with SolarEdge
> optimizers, which are inverters that mount at each panel. He also
> mentioned that SolarEdge does not recommend installing their inverters near
> a ham station.
>
> I suspect — but don't know for sure — that the Enphase inverters tend to be
> quieter because they have to meet the much more rigorous RFI standards of
> the EU. Enphase is a German company.
>
> 73,
> Frank N6OI
>
>
> On Sun, May 23, 2021 at 3:04 PM Mark Schoonover <mark@ka6wke.net> wrote:
>
> > The micro inverters I used were also from Enphase. 8KW system w/32
> panels.
> > Totally quiet.
> >
> > I wonder if solar RFI is related to single inverter systems? I don't have
> > any direct experience with them and don't have access to one to test.
> >
> > 73! Mark KA6WKE
> >
> > Website:
> > https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ka6wke.net%2F&data=04%7C01%7Cmike.carter%40unh.edu%7Cbe30e58d34904d7439d308d91e4adf92%7Cd6241893512d46dc8d2bbe47e25f5666%7C0%7C0%7C637574129195724674%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=tmXN79%2BP%2Fnn4lYVUzpXARAF3kwxS07TYm3mvjlDhHuw%3D&reserved=0
> >
> > On Sun, May 23, 2021, 15:01 Frank <kibbish@gmail.com> wrote:
> >
> >> My personal experience is that you will have no RFI problems with a
> solar
> >> system that uses individual microinverters at each panel so long as you
> >> use
> >> microinverters from Enphase. I have 22 panels (320W each) on my roof,
> and
> >> some of them sit less than 30 feet below my 6-band hex beam. I have
> >> absolutely no RFI from them on any band. I've spoken to several other
> >> hams
> >> that also have Enphase microinverters on their home solar systems, and
> >> also
> >> have no RFI problems.
> >>
> >> One thing that definitely helps in designing the system is having a
> solar
> >> installer that is willing to work with you to ensure the system is RFI
> >> free. The solar installation company that I selected knew nothing about
> >> potential RFI issues when I first contacted them, but they looked at my
> >> concern as an opportunity for them to learn. They were happy to put me
> in
> >> touch not only with their internal systems engineer but also one of
> their
> >> non-ham customers. That customer let me bring my KX3 and a portable
> >> antenna to their home and do a considerable amount of RFI sniffing on
> >> multiple bands to ensure that their system (which was similar to what I
> >> was
> >> planning to install) would not generate RFI.
> >>
> >> 73,
> >> Frank N6OI
> >>
> >>
> >>
> >> On Sun, May 23, 2021 at 2:37 PM <rfi-request@contesting.com> wrote:
> >>
> >> > Date: Sun, 23 May 2021 12:32:51 -0700
> >> > From: "Robert T. Devine" <rtdevine@comcast.net>
> >> > To: <rfi@contesting.com>
> >> > Subject: [RFI] SOLAR INSTALLATION PROS/CONS
> >> > Message-ID: <02c501d7500a$6d66aee0$48340ca0$@comcast.net>
> >> > Content-Type: text/plain; charset="us-ascii"
> >> >
> >> > Looking for information from those that have experienced Solar
> >> > Installations
> >> >
> >> > Pro's and con's appreciated
> >> >
> >> > Thanks
> >> >
> >> > Robert T. Devine, KC6AWX
> >> > Manager, ARRL 6th District Incoming QSL Bureau
> >> >
> >> >
> >> > "Save a Life...Become an Organ Donor"
> >> > 'Be kinder than necessary, for everyone you
> >> > meet is fighting some kind of battle.'
> >> >
> >> > ------------------------------
> >> >
> >> >
> >> _______________________________________________
> >> RFI mailing list
> >> RFI@contesting.com
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> >>
> >
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