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Can voltage fluctuation or “dirty energy” from my solar inverter damage electronics?

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  • Can voltage fluctuation or “dirty energy” from my solar inverter damage electronics?

    I’m curious to know if voltage fluctuation from my solar inverter may damage or reduce the life expectancy of some of my electronics. I don’t know all of the details of my system off-hand, but it is a grid-tied system originally installed by Solar city (now owned by Tesla), which is capable of producing 60 KWh on a sunny day.

    The reason I’m wondering about my inverter is that gas generators are known to damage sensitive electronics specifically due to voltage transients or so-called “dirty energy”. It was explained to me that when the voltage doesn’t come in as a smooth sin wave, it puts additional strain on electronics, particularly compressors for some reason, which can burn them out over time. In fact, many ductless mini-split AC manufacturers warn against running their systems on a gas generator for this very reason.

    After having an unusual number of electronics die on me (including my mini-split AC system, a burned out well pump and several other things), I began to wonder if my solar inverter was causing a similar problem. I got a Graham Stetzer microsurge meter and tested every electrical outlet in my home. The GS readings (which measure microsurges) were alarmingly high.

    Average GS in a neighbor home with no solar: 100 GS
    Average GS in my home during the day with active solar: 1200 GS
    Average GS in my home at night when panels are inactive: 275 GS

    To control for the fact that I am tied to the grid, and it’s hard to know if my inverter is the culprit, or if I’m getting dirty energy from the grid, I actually repeated the experiment when my solar system was dismantled while my roof was being replaced. During this period, I also repeated the experiment yet again with a gas generator running to see how my readings compare to a generator output…

    Average GS in my home with solar dismantled: 85 GS
    Average GS while running a gas generator: 1900 GS

    Yes, the gas generator produces the most voltage fluctuation, but what concerns me is the fact that the solar inverter produces values that are approaching that of a generator and that are more than 10-fold higher than what I’m getting from the grid. I’m concerned then that 1) micro-surges are considered enough of a threat to electronics for manufacturers to recommend against running them on systems known to produce high levels (such as gas generators), that 2) my solar inverter produces surge levels 14X that of a regular home without solar—levels that almost approach that of a gas generator, and that 3) and that I’ve had an atypical amount of electric device failure in a short amount of time.

    Does this sound like reason for concern to you?
    Is this a common problem?
    Do these GS micro-surge levels sound typical for a solar inverter, or is my situation unusual?
    Would a whole-house surge protector help?
    I’ve heard about phase filters, but I know very little about them—would they help?
    The company I’m leased to (Tesla) was extremely unhelpful regarding a simple issue I had a couple years ago, so I’m less optimistic that they’ll be of much help regarding this.


  • #2
    I have no experience with a microsurge meter. However, I would expect the most transients when
    running a generator off grid. These would be most likely when loads to the generator switch off
    and on. The grid tie inverter by definition is tied to the grid, which will tend to absorb any local
    transients. However the grid tie inverter will tend to raise the line voltage. If your setup (like mine
    used to be) has a lot of voltage rise, any other transients will look that much farther out of range.

    My opinion is the inverter is the least of your problems, the generator is the worst. A mini split
    line input, for inverter driven variable speed operation, goes into a powerful AC to DC rectifier
    that would be quite tolerant of line variations, and even tend to absorb them. I would not expect
    the minis to have a problem with line variations, 5 are running closely coupled to solar here, no
    issues so far. Lightning induced surges could be a problem, which could produce order of
    magnitude (or more) larger surges for a very short spike.

    Other electronics is going to be all over the map in its tolerance. I would expect standard
    electric motors to be near immune, except for extended low voltage into an induction motor.

    good luck. Bruce Roe

    Comment


    • #3
      Yes, it could. but it's very unlikely to be able to happen. Why ? Because pure sine inverters produce a very clean power signal. If they were to begin to fail, their output would degrade and then things would not work properly.

      What is a 'Graham Stetzer microsurge meter' ? I had to go look that one up.. and then I laughed. Then I cleaned my laptop screen. I would put it on the shelf next to the $900 pre-amp AC power cord and the NASA approved energy saver for your fridge.

      What Graham Stetzer appears to be doing best, is putting your money into his pocket. A blister pack device with no calibration standards. And no UL certification that they can boast about. And he's the only one that can detect it and fix it ......

      First, I want to talk about "dirty AC generators". A generator (or actually an alternator) is a device with a magnetic field and coil of wire moving relative to each other. Most commonly, these are built as a concentric circular arrangement with some carbon brushes to conduct electricity from the moving part. In the attached pic, you can see the 2 copper rings at the far end of the shaft. There will be a carbon brush (or sometimes a pair for redundancy) for each ring. The inner part, with the copper rings, spins inside the windings on the frame. As the poles of the magnets go past the wires, they create a sinusoidal wave, which is very nearly 100% pure sine wave. It does not generate dirty power, because that would be waste. If rotated evenly, it produces a perferct sine wave.
      Noise can happen when the brushes are worn and they make poor contact intermittently, which is why brushless alternators have been developed.
      But I'm not going into that today ( but you can https://www.marinesite.info/2014/03/...tor-works.html )

      Many "under PV panel microinverters" use a stepped high frequency pilot signal to develop the household 60Hz and they radiate their high frequency signal into the air (where it dissipates rapidly) and it can follow the copper wiring along till it reaches a transformer (which blocks signals much over 60Hz. Since the transformer is outside your house and commonly on a pole down the street, several households can contribute to local noise on the powerline, as will your neighbors arc welder, the electric mixer in the kitchen next door, and dozens of common household appliances. Even your high efficiency computer power supply (switching) creates this noise or "hash" on the local powerline. And it's been measurable since Nikola Tesla started developing high frequency AC tesla coils designed to propagate power across cities.

      The noise / hash is real. The magnitude of it is miniscule. Your neighbor down the street with his arc welder might be able to generate enough hash to damage a poorly constructed hi-fi.
      You might have a failing microinverter that is generating a lot of hash. But there is very little gear in the average house that would be damaged by it.
      Inverters have a spectral purity measurement that they must be designed to, Total Harmonic Distortion, and most household gear is easily OK with up to 10% THD

      If your neighborhood is prone to lightning, that is something that can generate damaging signals. A poorly adjusted generator can damage things. A properly functioning inverter should not produce damaging signals. You could have a bad inverter and maybe your $100 has pointed that out to you.
      (reload the page to watch the graphic generate a pure sinewave, the same way a generator does)

      ComplexSinInATimeAxe.gif



      alternator_cutaway.jpg
      Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
      || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
      || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

      solar: http://tinyurl.com/LMR-Solar
      gen: http://tinyurl.com/LMR-Lister

      Comment


      • #4
        You can repeat your measurements at night, when the inverters are off !!

        Try an outlet near your main electrical panel

        try the outlet when you are operating your : Microwave, blow dryer, plug in vacuum cleaner, Cell phone/tablet charger
        Each of those devices (or your neighbors on either side) should make that meter jump.
        Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
        || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
        || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

        solar: http://tinyurl.com/LMR-Solar
        gen: http://tinyurl.com/LMR-Lister

        Comment


        • #5
          Originally posted by Mike90250 View Post
          You can repeat your measurements at night, when the inverters are off !!

          Try an outlet near your main electrical panel

          try the outlet when you are operating your : Microwave, blow dryer, plug in vacuum cleaner, Cell phone/tablet charger
          Each of those devices (or your neighbors on either side) should make that meter jump.
          Good questions, Mike. I actually recorded tons of data, and can answer these.
          I chose an outlet that was close to my main panel as my standard test outlet. I did test every single outlet in the house as well, with varying levels of noise. The test outlet I chose was an average representative. When I connect and run appliances, the noise/hash readings increase with every subsequent device, so clearly devices and things like microwave can intensify the noise on the line, but a lot of noise remains when disconnected.
          When I do the recordings at night (inverter inactive), the hash/noise levels fall dramatically (from ~1200 during the day to 275 at night)--a nearly 90% reduction. In other words, the noise/hash on my electrical lines increases by a factor of 10x during the day, when my solar inverter is active.
          I repeated the recordings when my solar system was taken down for a month (roof replacement). During that time, my average readings were even lower still ~85 units, which further implicates my solar inverter as being the primary contributor to these signals.

          I understand the GS device and units are a bit goofy, but it's really all I've got to work with. Since I have no way to scientifically calibrate the device against a known source, I did the closest thing I could, which was to test the device on electrical sockets in the homes of several friends and family, so I can at least get a general baseline of what's typical. I tended to get values around 100 units in their homes (similar to what I get in my own home when solar was disconnected). Even if the precise meaning of the GS units is dubious, what the device does tell me is my electrical circuits are far for normal, by an order of magnitude, but only when solar is connected. So it at least tells me that something is off. And this same meter will record even higher levels (1900 units) when I did a test run with a gas generator. So the meter, for all its failings is telling a consistent story at least: most homes I recorded = 100 units, my home without solar = 85 units, my home with solar, during the day = 1200 units, my home on a gas generator = 1900 units.

          Why even be worried?
          The main concern is I have had an unusual amount of electrical devices fail in a short period of time (the four years since I got solar). This is what motivated me to do the readings in the first place, to see if something was going on with my lines. I even had an electrician come out and test the wiring and make sure there were no loose connections, bad grounds, bad neutrals, or bad bus connectors. Everything looked okay.
          But it was the warning by manufacturers that they put in big bold letters "DO NOT RUN THIS SYSTEM ON A GAS GENERATOR", and it was explained to me in general terms that voltage transients, or microsurges or something can either harm sensitive electronics or can cause undue wear and tear on motors, shortening their lifespan. If the problem is significant enough for manufacturers to put a warning on their products, then there must be some truth behind it (even if the warnings are conservative). Now, its true a gas generator produces far more hash (1900 GS units) than my solar (1200 GS units), but compared to a regular home without either of these devices (100 units), the noise I'm experiencing with solar is more than halfway to what you get with a generator. So I wonder, could this by why I experienced more problems with electric devices and motors (well pump, mini split) than any other home I've ever lived?

          I'm definitely experiencing more electrical problems or prematurely burned out motors than other places I've lived. And I've found a smoking gun (the high level of hash/noise on the lines). I have to wonder then, are these two things related? Is my solar inverter screwing up my electronics? Since other people who have solar don't necessarily have these problems, maybe Solar City installed mine incorrectly, or maybe one of the inverters is defective or something?

          Someone mentioned I should at least get a whole-house surge protector. I've also heard mention of filters? Or phase filters or something like that? But I don't know enough about electronics to know what is legit, and what's bunk.

          Final comment:
          This summer we had massive storms that brought down the electrical grid throughout much of my state. My brother is an HVAC technician, and he said during the week in which we had no power, he had to "graveyard" over twenty mini-split systems that week. He said over half of those homes had been running their mini-split on a gas generator, which is at least proof of the concept that the dirty energy or hash produced by a gas generator is enough to trash a system. My solar doesn't produce as much transient hash as a gas generator, but it's close, and so that's why I'm worried.

          Comment


          • #6
            Originally posted by ccarello View Post

            My solar doesn't produce as much transient hash as a gas generator, but it's close, and so that's why I'm worried.
            I have a mini-split and a lot of other electronics such as all my lights being LED. I run my house off-grid on a 4kW Magnum inverter ~90% of the time. Everything is doing fine. If you're grid-tied the grid is an infinetly more likely source of voltage transients than your grid-tie inverter.

            Comment


            • #7
              You have to look at meaningful noise. 90KHz "hash" has little effect on a motor being run from 120vac The motor inductance prevents any "hash" from getting into the motor and doing - - nothing. Nothing in a motor can be damaged by hash, until the hash becomes a predominant signal (which in a utility, would never happen)

              Why generators kill things is when folks let the tank run dry. As the generator slows down, the frequency drops, and below 50hz, a 60hz gear can be damaged from excess current flow.
              Inverters have a lot of high power electronics in them. Generators have brushes and regulators.

              I'm assuming it's your inverter that has a label to "Never connect to a generator" ? Because if the system loads become less than solar production, the solar will backfeed the generator and fry it. I've run a house full of electronics, 2 fridges and a freezer and a 1/2hp water pump, off my inverter for over 10 years. No failures
              If a grid-tie rated inverter had "noise" issues, the power company would not let you connect it to their system, where you could fry the neighbors gear and they sue the elec co.
              Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
              || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
              || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

              solar: http://tinyurl.com/LMR-Solar
              gen: http://tinyurl.com/LMR-Lister

              Comment


              • #8
                This device wouldn't be useful to detect the kind of line surges that could destroy motors and other electronics. It's for people who imagine that they are "electrosensitive" and are afraid of low-level RF to the point that they will spend money on imaginary fixes or demand that their smart meter be removed. It's a shame that people profit from their fears.

                Comment


                • #9
                  If you're worried about microsurges, go get a bunch of Ferrite rings and start slapping them on everything. They are relatively cheap, and highly effective. You'll need to make sure you get the correct ones, not all Ferrite rings are created equal.

                  Comment


                  • #10
                    Originally posted by sdold View Post
                    This device wouldn't be useful to detect the kind of line surges that could destroy motors and other electronics. It's for people who imagine that they are "electrosensitive" and are afraid of low-level RF to the point that they will spend money on imaginary fixes or demand that their smart meter be removed. It's a shame that people profit from their fears.
                    Oh, I see now, regarding that sensor device.

                    Thanks for the info everyone. The part about gas generators only become a problem once they start running out of gas and cause huge voltage dips. I've seen that before when a generator is running out of gas and starts "lurching" and the lights start flickering. It makes sense that would damage electronics, and not the ordinary background noise.

                    Comment

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