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Post by mediadogg on Aug 14, 2019 14:29:26 GMT
Ok, the device seems to be working as expected. The MOES now does not get a positive trigger voltage when the inverter AC is off, no matter what the battery status is, and thus defaults to the grid. So I was able to remove the ProWatt from the configuration. Spent $14 to recover a $70 item. Good trade. Now it remains to run for awhile to see if the switching happens reliably, and whether the GFC still trips. If it does, my next step is to disconnect the inverter ground wire - right now, all three ground wires are tied together: inverter input+grid input+MOES output. Edit: scratch that idea. I just read several manuals from both Samlex and Renogy on grounding of the inverter. I absolutely do not want to disconnect the inverter ground wire from the MOES, unless I run the inverter chassis to an earth ground, which I don't plan to do. So, the inverter is by definition grounded when its ground is connected to another terminal that is in fact bonded to the earth. And certainly my grid AC input ground is very well grounded to the water pipe in my home, assuming nobody has screwed up in the wiring to my AC outlet. My reading also confirmed that using low voltage disconnect circuits is a good thing, due to the complexity of determining the state of discharge of a battery under load. I know from experience that relying on the low voltage cutoff of the inverter can cause you to permanently damage your battery. By the time the inverter beeps or shuts off, your battery is already in serious trouble, and if it goes on too long, you will shorten the battery life. So, in answer to tattoo about all the gizmos, that is one I would recommend for any solar installation, even fully off-grid. Using one of those new LV disconnect circuits I referenced earlier, you can closely control how much stress you put on your battery, and keep it above 40% , 50% or whatever SOC you choose. Your own experience and environment will guide you how to choose the set points. And your battery will live to see many more cycles.
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Post by blade3609 on Aug 15, 2019 4:13:09 GMT
Do you have the diagram of how you wired that up exactly?
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Post by tattoo on Aug 15, 2019 10:09:55 GMT
So, in answer to tattoo about all the gizmos, that is one I would recommend for any solar installation, even fully off-grid. Using one of those new LV disconnect circuits I referenced earlier, you can closely control how much stress you put on your battery, and keep it above 40% , 50% or whatever SOC you choose. Your own experience and environment will guide you how to choose the set points. And your battery will live to see many more cycles.
That's some good info..... Thanks for posting that......
My batteries hardly ever are below 12.0 in the morning.... But that's at sag which is at start up of my fridge....... That's 12.2 at rest.... But by 11:00am at the latest my batteries are at 12.7 cloudy or not.....
Being off grid you can't really have something that will cut your system off unless there is a problem and it needs to be turned off......
I like my things in the fridge to be cold..... LOL
Thanks again...
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Post by mediadogg on Aug 15, 2019 12:12:32 GMT
So, in answer to tattoo about all the gizmos, that is one I would recommend for any solar installation, even fully off-grid. Using one of those new LV disconnect circuits I referenced earlier, you can closely control how much stress you put on your battery, and keep it above 40% , 50% or whatever SOC you choose. Your own experience and environment will guide you how to choose the set points. And your battery will live to see many more cycles.
That's some good info..... Thanks for posting that......
My batteries hardly ever are below 12.0 in the morning.... But that's at sag which is at start up of my fridge....... That's 12.2 at rest.... But by 11:00am at the latest my batteries are at 12.7 cloudy or not.....
Being off grid you can't really have something that will cut your system off unless there is a problem and it needs to be turned off......
I like my things in the fridge to be cold..... LOL
Thanks again...
Seems like your system has been well thought out, sized and configured for your needs!!
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Post by mediadogg on Aug 15, 2019 12:13:27 GMT
Do you have the diagram of how you wired that up exactly? Working on it.
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Post by tattoo on Aug 15, 2019 13:51:34 GMT
Seems like your system has been well thought out, sized and configured for your needs!! Yep I tried..... So far so good...........
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Post by mediadogg on Aug 15, 2019 19:31:12 GMT
Do you have the diagram of how you wired that up exactly? Working on it. OK, here is a system diagram. Hopefully I haven't made any gross errors. Please feel free to comment or ask questions. If I made a mistake, I can fix it. If I can improve my system based on your suggestions, that would be great! Literally minutes ago, I just confirmed that it is on the switch back from solar to the grid, that the GFC trips. Otherwise, everything working as desired. No matter what the reason that the AC from the inverter is not present, the AC sensing switch causes the MOES to ignore the battery trigger voltage. Hence, the UPSs that power my equipment always get AC so long as the either the grid or solar is producing power.
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Post by mediadogg on Aug 17, 2019 0:45:54 GMT
Talked with Samlex engineer again today. He explained that such inverters, not designed to be connected to a home power panel, and its GFC will trip when it detects the neutral bonded to ground, which happens in the way I configured the MOES ATS. I suggested that naybe I should just disconnect the inverter ground wire, and he agreed. So, in the diagram I posted, all is the same except the grren wire from the inverter now floats. And so far, it has worked. Will see what happens tomorrow. By the way, this still allows the GFC to protect the inverter and the human from an internal short in the inverter. If the hot wire touches the chassis, the GFC will trip, probably before the internal fuses blow.
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Post by mediadogg on Aug 17, 2019 22:46:18 GMT
Another day of ATS cycles. No GFC trip. Cautiously hoping that I finally got it solved by not connecting the inverter ground wire. Since the ATS is connected to a UPS, the loads are always grounded, even when being powered from the inverter. That's why the GFCI was tripping - it was seeing the neutral to ground bond of the house wiring being preserved by the UPS.
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Post by blade3609 on Aug 20, 2019 12:30:53 GMT
Good to hear mate! is it still good?
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Post by mediadogg on Aug 20, 2019 12:48:23 GMT
Good to hear mate! is it still good? Thanks, and yes no further trips since I detached the inverter ground from the configuration.
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Post by tattoo on Aug 20, 2019 13:58:48 GMT
Thanks, and yes no further trips since I detached the inverter ground from the configuration. That is really wild that a ground would cause that......... Glad you figured it out....
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Post by mediadogg on Aug 20, 2019 14:44:27 GMT
Thanks, and yes no further trips since I detached the inverter ground from the configuration. That is really wild that a ground would cause that......... Glad you figured it out.... Thank you. Yeah, the legacy design of that type of inverter did not consider they would interact with the grid in any way. They are made for standalone, and the GFCI correctly protects the standalone system. But I'm glad you reminded me ... I need to measure the potential difference between the inverter case / ground and grid ground. If there is any significant voltage there, I am at risk for touching the inverter case while in contact with mains ground. Bad news! If that turns out to be the so, I will have to scrap my design and get one of those "inverter / chargers," which have a built-in ATS and a modern design that uses relays to automatically take care of the neutral bonding conflicts ( see page 14 here). Edit: just checked, got about 5VAC. I will keep checking from time to time to make sure. But for now, seems OK.
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Post by blade3609 on Aug 23, 2019 15:24:50 GMT
Hows it going with the setup man ? still good? at what volt did you put the low switch and high switch?
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Post by mediadogg on Aug 24, 2019 18:10:34 GMT
Hows it going with the setup man ? still good? at what volt did you put the low switch and high switch? All good with both MOES units. Not at home now, and I don't recall the numbers, but they are different for the two installations because the loading, panels and sun patterns are different, so you will have to decide for yourself. I set the low point to be significantly above the battery protection board cutoff at maximum load, so that the inverter never beeps or shuts off (I think about 12.0 or 12.1), and I set the high point high enough so that the MOES is not flipping back and forth too often, but not so high that it never gets there on a cloudy day (I think about 12.8 on one system, but higher on the system that gets more sun).
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