Thanks for clarifying, Dave. When I saw some of the incorrect information
taking on a life of its own, I needed to jump in, although it is just luck that
I managed to read this deep into the thread. The ARRL Lab is running
shorthanded right now and I don't have as much time for these lists as I might
like.
First, the regulations. To summarize:
o Home solar systems are digital devices, classified as unintentional
emitters under Part 15.
o Home solar systems do not meet the criteria to be categorized as devices
that are exempt from the emissions limits.
o Large "solar farms" are also digital devices, but because they are power
generation not connected to residences, they COULD be classified as exempt from
specific limits. That has never been tested, but we do need to keep that in
mind.
o Under the rules, these solar systems are authorized by a Suppliers
Declaration of Conformity, or, optionally, certification.
o An SDOC is essentially a self-validation, where the manufacturer issues a
statement that it complies with the rules. For the most part, from all
indications, these devices do.
o Under the Class B rules, devices that are not exempt must meet conducted
emissions limits onto the AC mains below 30 MHz. They must meet radiated
emissions limits above 30 MHz. The conducted noise onto the wiring to the
panels is not regulated by Part 15. From all we can tell, the solar systems
being marketed do meet the letter of the emissions limits rules.
o Manufacturers are responsible for having designs that meet the emissions
limits and for marketing them appropriately. For example, a solar system could
be designed for installation on businesses in a way that met the higher
commercial limits, but it must be marketed only for use in commercial
environments.
o These are the ONLY EMC requirements that the manufacturer must meet.
o The rules also stipulate that otherwise-legal devices must not cause
harmful interference to licensed radio users such as amateur radio, CB,
broadcast reception etc. This is a requirement that is placed on the OPERATOR
of the solar system, ie a neighbor, the ham him/herself or, in some cases, the
utility or third party. So, when a manufacturer steps in to address harmful
interference, it is doing more than the rules require. This is important to
know.
Those who observe that the limits are high are correct. If a "barely legal"
Part 15 device of any sort were operated in the home of a neighbor 100 feet
away, for example, noise around S7 would be typical, plus or minus. Almost all
of the cases that ARRL takes to the FCC are moved forward on the basis of
harmful interference, making measurements of conducted and radiated noise
irrelevant. The FCC has taken that issue seriously enough to authorize
considerable staff time to writing a good number of advisory letter, so it does
care, but needs help to direct its resources efficiently.
Now, part of the crux of the issue is "harmful interference." Not every noise
is harmful interference to the FCC. The definition is vague, and we want it to
stay that way. If we were to ask the FCC to draw a firm line in the sand and
set a level for "harmful interference," it is almost certain that the FCC would
draw a line we don't like. If, for example, it drew the line at the current
conducted and radiated emissions levels, we would be looking at some pretty
serious noise.
There is, of course, ambient noise everywhere. The median level of man-made
noise on HF ranges around S6 on the lower bands, S4 on the higher bands.
Harmful interference complaints below this level are usually not well received
by the FCC, under the principle that half of the locations in residential
environments have this noise level half of the time on half of the frequencies,
so even when noise levels changes, it considers the noise to be typical of
noise everywhere.
This doesn't mean that hams are always stuck. To the contrary, all three of the
solar companies I am working with is looking to reduce the noise from their
systems as low as can be done, although below the levels I described, this is
still a work in progress.
So the bottom line is that hams can relief, effectively for strong noise
sources, and, in the long run, hopefully at lower noise levels as well, with
the industry going over and above, or under and below, what the regulations or
FCC would mandate if pressed.
This is much like the BPL days, when parts of the industry resisted notching
the ham bands, but other parts implemented those notches, to good effect. That
got picked up internationally and made part of the ITU requirements for BPL.
So, in the US, we "lost" the regulatory battle, but behind the scenes, worked
with the "good guys" who helped bring the effective EMC solutions to the table
internationally.
We are seeing the same sort of thing with the solar companies that are involved
in interference complaints doing more than the rules require and looking for
ways to do better yet.
As I have learned in my industry standards work, this is the real way things
get done, because all the rules in the world are not enough, but cooperation
and reasonable expectations and a bit of patience are. I was patient for 14
years with BPL and, in the long run, not only did it solve the problem, but
that patient and technically honest approach built the reputation of amateur
radio to the point where our presence in industry circles is both welcome and
wanted, with amateurs elected to leadership positions in major industry
organizations and committees. (For example, ARRL is a member of the C63 EMC
Committee, chairing subcommittees, writing standards that are incorporated by
the FCC into its rules. I also serve on the IEEE EMC Society as its Vice
President for Standards. All of this was possible because we took a steady and
technically correct approach to helping to solve problems.
Ed, W1RFI
________________________________
From: David Eckhardt <davearea51a@gmail.com>
Sent: Thursday, December 16, 2021 6:19 PM
To: Hare, Ed, W1RFI <w1rfi@arrl.org>
Cc: Ken Bandy, KJ9B <ken.kj9b@gmail.com>; Rfi List <rfi@contesting.com>
Subject: Re: [RFI] Noise from Generac Solar controllers?
Yes, I may have jumped to conclusions too fast based on what I wanted to see.
Apologies to everyone on the RFI list. I've been out of it in retirement for
some 11 years and am not as sharp as I once was.
However, I do have a LOT of problems with the whole solar power industry
ignoring what they know to be true. The statement from SolarEdge confirms that
wrt "HAMS". Until they are called on the carpet, nothing will be done -
remember BPL. In that respect it seems that ARRL has assumed the role of the
old FCC I once knew when first licensed in 1960. Sad, but ARRL is highly
capable. Just that my patience is wearing thin wrt the solar power industry
and RFI. Sure, it costs money and better and more rigorous instructions for
instals. But, come on......! We have enough RFI coming in from China with no
attention (or ignoring) EMC/RFI requirements.
This is all from me for this thread.
Dave - WØLEV
On Thu, Dec 16, 2021 at 10:24 PM Hare, Ed, W1RFI
<w1rfi@arrl.org<mailto:w1rfi@arrl.org>> wrote:
You are not “well aware” if you were looking in the FCC certification database
for reports on digital-devices unintentional emitters. They are not required
to file anything into the certification database.
I do not find the words “Class C” anywhere in Part 15. There are Class A
industrial devices and limits and Class B residential devices and limits. You
may be talking about the section in Part 15 Part C, intentional emitters. Those
are certificated, but Part C devices are not industrial devices; that is the
description of intentional emitters.
From: David Eckhardt <davearea51a@gmail.com<mailto:davearea51a@gmail.com>>
Sent: Thursday, December 16, 2021 5:17 PM
To: Hare, Ed, W1RFI <w1rfi@arrl.org<mailto:w1rfi@arrl.org>>
Cc: Ken Bandy, KJ9B <ken.kj9b@gmail.com<mailto:ken.kj9b@gmail.com>>; Rfi List
<rfi@contesting.com<mailto:rfi@contesting.com>>
Subject: Re: [RFI] Noise from Generac Solar controllers?
Yes, ED, I'm well aware of all that. In my looking at all the reports filed
with FCC, none addressed the complete system, only the intentional radiators
(Zigibee, BlueTooth, or whatever). Yes, as a Class B filing, no report is
necessary. They must have modified those wireless modules, likely the antenna
or digital format, to require testing and approval. No one in their right
mind as a user of widely available wireless modules wants to own the FCC
approval for those. Let the suppliers own the regulatory requirements. If
they are modified in any way, antenna or digital protocol, then, yes, the user
must certify the module.
And why do the filed reports - all of them - claim compliance to Class C,
industrial?
Dave - WØLEV
On Thu, Dec 16, 2021 at 10:07 PM Hare, Ed, W1RFI
<w1rfi@arrl.org<mailto:w1rfi@arrl.org>> wrote:
David,
Solar systems are digital devices that are classified as unintentional
emitters. If they are marketed into residential environments, they must meet
Part 15 B emissions limits. The only unintentional emitters that require
certification that would create an entry in the database you looked at are
scanning receivers, radar detectors and access BPL devices. Although they CAN
certify if there is no US resident willing to take responsibility under a
Suppliers Declaration of Conformity, the vast majority of unintentional
emitters are not certificated, so there will be no information on the FCC page
containing test data. An SDoC is essentially self-policed. The rules do not
require that test data on devices authorized under an SDoC be provided to the
FCC.
If they are using a certificated WiFi or Zigbee device that is used intact, its
certification would suffice, so there would not be a need for a separate entry
in the database, no more than you would need to certificate your station if you
bought and installed a certificated Bluetooth microphone in it.
Ed, W1RFI
-----Original Message-----
From: RFI
<rfi-bounces+w1rfi=arrl.org@contesting.com<mailto:arrl.org@contesting.com>> On
Behalf Of David Eckhardt
Sent: Thursday, December 16, 2021 4:55 PM
To: Ken Bandy, KJ9B <ken.kj9b@gmail.com<mailto:ken.kj9b@gmail.com>>
Cc: Rfi List <rfi@contesting.com<mailto:rfi@contesting.com>>
Subject: Re: [RFI] Noise from Generac Solar controllers?
IN further poking around on the FCC OET site under Generac, I can't find a
single report filed on anything except wireless hardware. I could not locate
any complete systems which would include the panels, optimizers, other
electronic switching devices, and simulated house wiring. There is no evidence
in the reports of any test results being filed with the FCC for the entire
system. All the "Max Freq '' frequencies listed on the response pages for a
general search on Generac on the FCC OET pages reflect only above roughly 700
MHz. This tells me they are only filing for the intentional radiator, that
being ZigBee or BlueTooth or some other protocol. No complete *system test* is
filed with FCC. So, how can they claim compliance to even Part 15, Subpart C
(Intentional radiator), Class C (industrial). BTW: Class C systems *do*
require filing a test report with FCC. There is none.
Dave - WØLEV
On Thu, Dec 16, 2021 at 5:06 AM Ken Bandy, KJ9B
<ken.kj9b@gmail.com<mailto:ken.kj9b@gmail.com>> wrote:
> Hi all. I am contemplating having a “PowerHome Solar” power system
> installed at my house, and am a little concerned about possible RF
> noise generation from the system. This system uses a Generac
> controller. Does anyone have any experience with a system using a
> Generac controller? I know early inverters were often RF noisy, but
> I’m hoping that the later models have addressed noise generation.
>
> Any input is appreciated.
>
> 73,
> Ken, KJ9B
>
>
> _______________________________________________
> RFI mailing list
> RFI@contesting.com<mailto:RFI@contesting.com>
> http://lists.contesting.com/mailman/listinfo/rfi
>
--
*Dave - WØLEV*
*Just Let Darwin Work*
_______________________________________________
RFI mailing list
RFI@contesting.com<mailto:RFI@contesting.com>
http://lists.contesting.com/mailman/listinfo/rfi
--
Dave - WØLEV
Just Let Darwin Work
--
Dave - WØLEV
Just Let Darwin Work
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|