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Ben Harper

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Everything posted by Ben Harper

  1. I finally figured it out! There are two ground/earth terminals on my inverter: The AC input ground The inverter output ground I assumed that these two are bonded together. They are not. I connected these two, and now everything is happy. A few days ago my RS232/USB adaptor that I use for comms with the inverter stopped working, and now I'm wondering if this is what killed it. Also, in case anybody else finds this post in future -- the PCB of the inverter seems to be connected to the Output Ground. So if you're connecting the ground terminal of your batteries, and you have a different input and output ground, then connect the battery ground to the inverter's output ground (not the AC input ground).
  2. These measurements hold for all pairs of ENL, no matter where I measure them: E-N: 0 E-L: 230 N-L: 230 I have a cheap multimeter, and it actually reads 198 instead of 230, but the numbers are consistent. I also discovered one other thing of interest this morning: The earth line in the garage is not connected by a copper wire to the house earth. Instead, the garage has its own earth spike, which goes into the ground about 5 meters away from the outside Eskom connection point of the main house. However, as I mentioned in my original post, I cannot measure any voltage between the house and garage earths. The only "signal" I can get between them is 1 ohm resistance.
  3. Error 61 on Kodak/voltronic inverter means the inverter is failing to talk to the battery. No mystery there. The problem I'm facing is that I get error 61 only when plugging in my alarm system, and only when using the earth from the house DB board. Details: Kodak 6.2kw inverter 2x pylontech up5000, talking to inverter over standard rs485 cable The inverter and batteries are in the garage, which is about 5m away from the DB board of the house. I've run a pair of live/neutral 6mm cables from the inverter back to the house DB board, for future insertion in there. I was hoping that I didn't need to also run an earth cable with that pair, because the earth of the house should be bonded to the earth of the garage. This is where it gets beyond me. If I run an extension cord from the inverter to the house, and plug the alarm system in, then no error. But if I use my 6mm live/neutral pair, and use the earth from the house DB, then I get error 61 when plugging in the alarm system. So far no other appliances cause the error. Using a cheap multimeter, I measure zero voltage difference between the extension cord earth and the house DB earth. But I do measure 1 ohm of resistance between them, which seems normal enough. The earth wires of the battery are directly connected to the earth on the inverter. One more thing: the earth line of the garage goes into a cable that runs underground towards the house. I'm not sure if it eventually connects to the house via a copper cable, or if there's an independent earth spike there. But as I said, I can't measure any voltage between these two (tried AC and DC) Can anybody explain what's going on here? I would think that since inverter and battery are directly earthed together, whatever happens downstream shouldn't affect the RS 485, but somehow it is. Thanks for reading!
  4. Now that I have a crimper, I might as well do it properly.
  5. Here's a spike from today, showing PV Amps, PV Volts, PV Watts, and Load Watts. Sampling interval is 1 second. Does this tell us anything else? There could be large load spikes with <1s duration, but I don't see a general pattern of large loads during the depressed PV periods.
  6. The video doesn't mention a single reason why isolators can cause fires, or did I miss something? Surely a properly specc'ed and installed PV isolator is a perfectly fine thing to have, especially if your inverter doesn't have a built-in isolator?
  7. I'm watching my solar production on these crazy hot days in Stellenbosch, and I'm noticing a few spikes in solar production, where the voltage (and watts) drops off for a burst. The voltage drops last between 10 and 40 seconds. I've posted an example graph below. My question is what is causing this? I don't see any clouds in the sky, but perhaps these are clouds that are not visible to me? Obviously if it's clouds, then nothing to worry about. What scares me though, is that when I originally installed my panels, I didn't have a proper MC4 crimper, so I just squashed the connectors on with pliers. I'm wondering now if on these crazy hot days, the drops in voltage are due to arcing inside the connectors. This system has been running for 4 years now. 8 x 330W panels in series 5.6 kW Kodak OG inverter
  8. The mounting bill is already looking steep, but I'll follow this advice.
  9. Thanks @Sidewinder, that is very useful. Mounting the rails straight to the roof looks like it would save a few R, but why do you say it's good to have ventilation between the panels and the roof? I don't know anything about aerodynamics, but my gut tells me that a smaller space between panel and roof would produce less wind force trying to pull the panels off.
  10. Now that I think more about this, you must be right. I was thinking that the purlins might be so weakly attached to the trusses that the purlins would pull out. But that is ridiculous, because then the whole roof sheet would rip out. There must be hurricane brackets between the purlins and the trusses.
  11. The ceiling is parallel to the roof beams - you can clearly see the main trusses from inside the house. Thanks @Virwat - that makes total sense that one can see the beams sticking out the bottom of the roof. I'm not here right now, but that makes perfect sense.
  12. Thanks - I understand now how the T-Bolt attaches to the rail. @Sidewinder - are you suggesting that I ensure the bolts go all the way down into the main roof beams? The house is in Pringle Bay, so wind is indeed a serious issue. If the bolts need to go directly into the main beams, how on earth does one locate them from the outside?
  13. I'm going to try to answer my own question here. 1. Hanger bolts about 1m apart 2. Attach rails onto the hanger bolts (2 rails per panel). Rails mounted horizontally, if panels are portrait Drill horizontal holes into the rails to attach to the hanger bolts 3. Use mid clamps and end clamps to bolt the panels down to the rails (mid clamp) 4. Place end caps to cover the rails Does that sound right?
  14. So what does one attach onto the hanger bolts? Does one place a rail onto the hanger bolts, and then mount the panels to the rails, or do the panels go straight onto the hanger bolts (with some kind of clamp thing obviously)?
  15. I measured the bolts currently on the roof, and they're 100cm apart, and I assume that that roof is bolted into every purlin. What is the bolt called that you've posted here, and do you know where I can buy them? Also, I'm guessing that you attach a rail onto that bolt, and then the panel onto the rail? And yes, the angle is menacing. Just steep enough to slide off. I'll build a hooked ladder for the job.
  16. What's the recommended way of mounting solar panels to a fiber cement roof (sheets, not tiles)? I assume whatever screws one puts in need to penetrate into the wood, because the fiber cement is not strong enough. Also, it seems desirable to get the screws to mount to the main roof beams, instead of just the purlins, because the purlins are usually just nailed into the main beams. If this is the case, how do you locate the main beams from the outside? I live in the Cape Town area and I enjoy doing these kinds of things myself, so looking for a place where I can purchase the necessary stuff, and some recommendation on suitable equipment. I've attached a picture of the roof. Thanks!
  17. Yes.. you guys are right. This morning the max charge amps are 100.
  18. Thanks @P1000, that makes sense. I'm thinking now that it's likely that it was always present, but I just never noticed it before. Also, I saw that as the charge percentage neared 100%, the "02" setting went down further.
  19. OK.. interesting update. I've now plugged the batteries in parallel, and used my original UP5000 as master. Now my max charge current is fixed at 40A.
  20. I've been running a Kodak OG5.6 KW (MKS IV) with a Pylontech UP5000 for a few months now, and zero issues. Today, I plugged in a new UP5000, which I plan to run in parallel with the existing one. The weird thing is that after 5 minutes of charging my new battery at high current (50A), my inverter changed it's "max charge" setting (02) to 20A, and I am unable to change it back. On the control panel, it appears happy to accept my previous max charge current (50A), but this has no effect, and when I go back in a 2nd time to alter that setting, it's back at 20A. I'm unable to make it higher or lower - it's locked at 20A. I'm using the BMS cable, and it's on the Pylontech program setting. Has anybody else seen this? I'm hoping that if I make my original battery the master, then sanity will be restored... but this is really odd.
  21. @Twakdaddy, is your inverter connected to your battery with a comms cable?
  22. Hi @WernerM, You should be able to find a manual for your inverter. You'll want to read through the various settings available to understand them. There isn't actually very much. Basically, what you'll want to do is: Set the "voltage point back to utility source when selecting “SBU”" - try 48V. Probably setting number 12. Set the "voltage point back to battery mode when selecting “SBU”" - try 50V. Probably setting number 13. Set the charger priority mode to "Solar First", aka CSO. Probably setting number 16. Set the output source priority to SBU. Setting number 01. You have a little bit of a problem here, because your inverters don't have the ability to switch between SBU and SUB on a timer. The newer ones have this timer mechanism, which allows you to switch to SUB when the sun goes down (eg 17:00), and then switch to SBU a little later (eg 20:00). Being on grid power at dusk ensures that you'll be able to "survive the night" on battery power, and by the time the sun rises the next morning, you want your battery to be at say 20% capacity remaining, and then charging and loads must be powered by the sun. Your setup has a classic problem of being able to power 10kw of loads, but you don't have enough battery juice to power all that load between sunset and sunrise.. so your only hassle-free choice is to leave your system in SBU mode, and trust the inverters to automatically switch between battery and line mode. This is a nuisance when the sun is down, because the system will continually charge the battery, then drain it, then charge it, then drain it, ad infinitum. My solution to this problem is to run software that I built myself, via a Raspberry Pi (https://github.com/bmharper/homepower). There is possibly other software out there too, which does the same thing. I've never had two inverters in parallel, so I don't know how the control logic works in that scenario. In the absence of a timer based SUB/SBU switch mechanism, the only thing that I can think of is for you to try to reduce your power usage at night time.. to avoid that pointless charge/drain cycle. Hope that helps a bit.
  23. But wait.. there's more! I just figured out a big culprit in my setup: My "Back to Grid" voltage was 47, and this morning while it was cloudy and load was high, this was triggered. My "Back to Battery" voltage was the default setting of 54, and my Pylontech battery will never go that high. So the moment we hit 47 V, we get stuck in "grid" mode, and never come out of it. It still seems wrong that the inverter won't mix PV power into the load when in grid mode, or keep the battery at a floating voltage, but at least I can work around this particular issue.
  24. This forum post is an attempt to bring this issue to Voltronic's attention. As @Coulomb has mentioned many times, and now myself and many others have observed, our Voltronic inverters will cut off all PV power once the battery is full, and then start charging again once the SOC drops lower. This prematurely shortens the life of the battery, because it ends up performing more charge/discharge cycles than necessary. This only seems to happen when a BMS cable is plugged in. Here is a graph demonstrating this in action: As you can see, once the Battery SOC reaches 100% just after 12:00, PV power (green line) cuts out, and does not power loads (orange line). PV power idles at around 100W, which looks like the inverter's internal power usage. When the battery SOC drops briefly to 99%, at 13:25, then PV power once again kicks in, but then the battery hits 100%, and PV cuts out again. To be clear, the problem is this: PV should not cut out. It should continue to power loads. My equipment: Kodak MKS4 5.6 kW 1 x Pylontech UP5000 battery with RS485 cable attached 8 x 350W PV panels I'm going to refer to this forum post when trying to contact Voltronic support. If other people are able to graph their metrics which show the same problem, then please share your data here.
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