[RFI] Question Regarding Variations In Solar Panel RFI?

[Tony]

James:

Jim (K9YC) gave TJ recommendations on the type of chokes that were to be 
installed on my neighbors installation. However, I'm not sure how much 
of Jim's design was actually used.

Have you had the time to evaluate the RFI since the chokes were 
installed? Can you give us a before and after evaluation on the noise?

Tony -K2MO


On 9/25/2020 8:33 PM, WW3S wrote:
> Tom, aka TJ, is pretty good.....you are correct, he doesnt like Tonys 
> article from Arpil 2020, not sure why, but the retrofit they did at my 
> neighbors was very similar except they used clamp on ferrites, big son 
> of a guns.....Paul is probably monitoring, he can chime in if he 
> wants, but the engineer I had was Mike, and was very familiar with the 
> work done at Pauls....I didnt get a good look at the ferrites, they 
> were already on the roof when I saw them, but they twisted the heck 
> out of the wiring, and replaced all the optimizers.....Paul thought 
> they used type 31 ferrite, but in an email from TJ, he said the used a 
> type 75, ECM-IN-66OHM (maybe their part #)...he also said they 
> eliminated a ground fault pitch point ?!?!?!?
>
> ------ Original Message ------
> From: "Tony" <73guddx at gmail.com>
> To: "Rfi List" <rfi at contesting.com>
> Sent: 9/25/2020 8:03:23 PM
> Subject: Re: [RFI] Question Regarding Variations In Solar Panel RFI?
>
>> Jim:
>>
>> Tom Simpson (Solar Edge Engineer) will be visiting the site sometime 
>> in the near future so I'm hoping he'll address the potential problems 
>> you mentioned.
>>
>> The issues you describe may also explain why the suppression hasn't 
>> been very effective. The noise was 15db over S-9 prior to the 
>> suppression being installed and it's now S-9 plus a tad for a 
>> reduction of roughly 10db.
>>
>> This installation may require the methods used by Tony Brock-Fisher 
>> which includes chokes between the inverter and mains which is 
>> something Solar Edge frowns upon. Not sure if it's a cost or a code 
>> issue.
>>
>> Thanks Jim.
>>
>> Tony -K2MO
>>
>>
>>
>>
>>
>> On 9/25/2020 6:49 PM, Jim Brown wrote:
>>> Tony,
>>>
>>> There are MANY variables and wiring errors and system layout errors 
>>> that can contribute to how much RFI is radiated. One issue that Teff 
>>> communicated to me was that the framing holding the panels was 
>>> bonded to ground on the other side of the building from the power 
>>> entry. If this is true, it creates a current loop that could be 
>>> causing or contributing to your problem.
>>>
>>> Wiring can be prevented from radiating by shielding, IF, AND ONLY 
>>> IF, the shielding is continuous. In the real world that I'm aware 
>>> of, the only shielded AC wiring is that which is enclosed in steel 
>>> conduit, that is continuously bonded together. That's quite rare in 
>>> residences, except in cities like Chicago, where the Electricians 
>>> Union has it written into the city's Electrical Code as a means of 
>>> providing more work to Electricians.
>>>
>>> Running twisted pair for power can prevent radiation from the 
>>> current-carrying conductors (phase and neutral), but won't help with 
>>> common mode RF current, which is nearly always on the green wire. 
>>> And the common mode current is there because of bonding failures, 
>>> either in the construction of the equipment itself, or in the 
>>> installation, or both.
>>>
>>> The wiring inside the home could be hot with RF as a result of 
>>> wiring errors at outlets, at panels (double-bonded neutral), even 
>>> bonding at equipment. At the home I bought in California, I found an 
>>> outlet wired with neutral and ground reversed, and I found outlets 
>>> in the kitchen of a "mother-in-law" garage apartment fed between 
>>> phase and green rather than phase and neutral. I also found no 
>>> ground at all at the service entrance -- it was bonded to a hose 
>>> outlet that was fed by PVC pipe!
>>>
>>> 73, Jim K9YC
>>>
>>> On 9/25/2020 3:22 PM, Tony wrote:
>>>> All:
>>>>
>>>> The reports I've read suggest that the strength of interference 
>>>> caused by solar panel systems can vary from one installation to the 
>>>> next EVEN when the distance to the source is similar. That 
>>>> variation could be attributed to radiating conductors tied to the 
>>>> system such as the house wiring.
>>>>
>>>> We found high levels of RFI on the A/C lines throughout my 
>>>> neighbors home and that's likely the case with all Solar Edge 
>>>> installations since there are no chokes between the mains and 
>>>> inverter.
>>>>
>>>> Given those facts, would a large home with long runs of un-shielded 
>>>> Romex produce higher levels of interference compared to a smaller 
>>>> home with shorter runs? Or does the resonance of the wiring play 
>>>> more of a role than length and number of runs?
>>>>
>>>> It's an oversimplification, but it seems logical to consider what's 
>>>> connected to system and not just the system itself.
>>>>
>>>> Tony -K2MO
>>>>
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>>
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