QRM solarpanel / Inverters

Discussion in 'General Technical Questions and Answers' started by PA2DRE, Jul 4, 2019.

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  1. PA2DRE

    PA2DRE Premium Subscriber QRZ Page

    Hi has anyone got experience with solving the huge amount of qrm the, in my case micro inverters, give on HF ? I've got 16 panels from Astronergy type CHSM661OM-270 equipped with Grid-connected Micro-inverter type:YC500A. In discusion with the supplier he told me to switch off the system and see what in brings, S-meter readings went back from 9+20-30dB t0 5 and made it possible to work stations in daytime.
    Clearly I did not put solarpanels on my roof to switch them off hi..
    Any advice / suggestions are welcome thx in advance PA2DRE
  2. KD0CAC

    KD0CAC Ham Member QRZ Page

    1st , but that is problematic , local regulations " should " not allow electronics to cause issues like you are mentioning .
    But - the big BUT , our FCC isn't doing very well in this area either ;(
    After that , I would suggest taping something like aluminum foil over the inverters to the back of the panel , ideally removing from panel to get complete coverage .
    Next is picking the correct mix of ferrite for the wires , not an expert in this are , but possibly adding ground wire to both the foil-shield and ferrite .
    This is aside from my very 1st normal suggestion - eliminating the source of RFI .
    Another thought , what is the physical relationship of your solar panels & antenna - maybe too close ?
    Then your feedline , keep distance and runs of wire perpendicular to each other .
    PA2DRE and K0UO like this.
  3. PA2DRE

    PA2DRE Premium Subscriber QRZ Page

    Hi KD0CAC, thx very much for the reply all info is welcome. I tried to deal with the issue directly with the supplier, after another mail to him that I wrote I'd inform the local agency about this he called me and told me he needed some more time and help from the manufacturer.
    There is a new invertor he wants to try, has something to do with data being transferred to the system logger.
    The system is grounded one thing might be an issue the antenne starts "close" to where my panels are, the coax is not really that close to the invertors. Hopefully he will help solving this, I've already looked in to the ferrite solution and to me it most certain this will become a mix of solutions.
    I'll keep you posted about this, probably more amateurs will face this and the solution is something that will be applicable everywhere to my opinion.
    K0UO likes this.
  4. KP4SX

    KP4SX Premium Subscriber QRZ Page

    There's another thread going where a fellow IS getting good support from his supplier. I don't have a link handy, though.
    Good luck with the situation.
  5. KF5LJW

    KF5LJW Ham Member QRZ Page

    Good luck, you got what you asked for. Solar is notorious for generating noise.
    K3XR and K0UO like this.
  6. PA2DRE

    PA2DRE Premium Subscriber QRZ Page

    Ok Yes that's also a way of looking at this, well thanks for the constructive answer. There are however really good solutions so I still have hope this is getting solved.
    The supplier is willing to help, had him on the phone yesterday and he told me he had a similar situation that was solved with other invertors, so one of these days it will be delt with. Thx for he response..
    KP4SX likes this.
  7. KN4DQE

    KN4DQE Ham Member QRZ Page

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  8. KD0CAC

    KD0CAC Ham Member QRZ Page

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  9. PA2DRE

    PA2DRE Premium Subscriber QRZ Page

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  10. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    First of all I'm going to say that some inverters or controllers can be very quiet and you don't even know they're on and in use.
    But I would estimate if we're real lucky in the United States that's about 1 out of 10!!

    My neighbor in Breckenridge Colorado, a city that was looking at going totally solar on new construction, had a 6000 watt unit. I had 40/9 noise and he was a quarter of a mile down the mountain from me. I got real lucky when I contacted the company that he was leasing the panels from and it was a bad controller and the noise went away.

    I also RV all around the country and inverter generators and solar panels are everywhere and the noise is terrible most, every unit is bad at some frequency.

    As an example, in Quartzfest last Jan in AZ, we had over a thousand hams and at sunrise the noise went from about an S two to in some cases totally unusable on HF.
    Anybody considering purchasing solar controllers of any size from 100w to 10000 Watts needs to be aware that this is probably going to be an issue and you need to have an "out" with your supplier.
    Do a lot of research before you put the cash out for any kind of unit.

    The same applies if you're buying a generator with a built-in inverter.

    Fixing the problem on most any of these units is nearly impossible. I've worked with several excellent engineers in the past. We were going to do some tec talks on it to try to help people. Unfortunately we have never been able to make any major noise reduction on any of the units. And we've invested lots of time and effort in trying to do so. Everybody is hoping for a magic box or a toroid, it's not that simple. Even some of these units had an FCC type accepted stamp on them, so I wonder about the authenticity of the stamp or the lab that certified to unit.

    My best advice "don't buy tell you know" or have a "way out" if you buy and it's noisy, otherwise it's like buying a house in an HOA and thinking you "might be able to put up an antenna".
    Some of these units cost many thousands of dollars plus the labor for install. Don't be stupid in this day and age everybody knows noises is everywhere from all types of sources, why wouldn't you be suspicious of something that's actually supplying the AC or DC power, buyer beware.
    Last edited: Jul 8, 2019
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