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Chris Hobson

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Everything posted by Chris Hobson

  1. Hi All After a period of absence I am back without my much loved dual Axpert install. I now lived in (clears his throat) Gqeberha (Port Elizabeth for those of you without a throat infection). My new home has a 3 phase supply and a massive 30 kVA 3P generator for the regular power outages. Heaven help us once loadshedding starts. The roof is slate and probably singularly unsuitable for a PV install. Not to be defeated I do see there is space for a double carport which will then accommodate PV on the roof. At this stage I am looking at a Solis 3P GTI. Anyone have a system that they find superb? Chris
  2. I just want to check you have a combiner box for your 5S/2P array.
  3. OK CB on PV to MPPT and depending on load CB/battery disconnect between battery and load I have seen a 125A DC CB but they are not common.
  4. Use the direction of current flow into the switch i.e. the source side (PV in this case). You understand why you cannot use a DC CB between MPPT and batteries as sometimes the MPPT is the source and sometimes the batteries are the source. If you have a separate set of wires directly from the battery to load then you can have a CB between MPPT and batteries but then you need a CB/battery disconnect on the load cables depending on the maximum possible draw. I think you have a Victron MPPT. Some Victron MPPTs have terminals for load and others do not. I would be inclined to have a DC CB between PV and MPPT and a battery disconnect between batteries and load. A second DC CB would be superfluous between MPPT and batteries. Just make sure your cables are specced properly.
  5. Morning you need to be careful wiring up DC breakers so that the magnetic field directs the DC spark into the catch cage. If the source is your PV you can bring the wire into the CB either at the top or at the bottom like an isolator but then you must be consistent and ignore the + and - on the other side. Your current flow between MPPT and battery is usually bi-directional and DC circuit breakers are not designed for bi-directional use. The Amps you are going to draw from your battery is could exceed what a DC breaker is able to switch. So I would recommend you have a DC breaker between PV and MPPT and a battery disconnect between battery and MPPT. You don't mention what size you PV array is and whether the array is made up of several strings or the size of your inverter. So my recommendation is made with incomplete facts. https://www.youtube.com/watch?v=Cup5fMGaE2g
  6. The fan speed is definitely related to the SCC. We are having a day with broken cloud and the fan speed is varying all the time. Since I have the model with external SCC heatsink the increased fan speed seems unnecessary although I would admit the heatsinks are considerably cooler.
  7. I am going to have to go back to 72.70c. The noise levels are too distracting and although the ability to go into standby is really convenient the noise trumps it. I don't think the fact that the machines run 8 degrees cooler can be used to argue in favour of the more responsive fans. Reversing the fans in 2016 has already got the machines running 15 degrees cooler.
  8. Morning Gerrie - the inverter not switching back on is due to the battery voltage being too close to the battery low cutoff voltage. What the difference needs to be depends on what firmware you have. With @Coulomb's lithium firmware I think it is 2V and vanilla it's 4V. It may be 1V and 2V respectively I can never remember. You can solve this by temporarily lowering the setting of Program 29, switching on the inverter and raising the setting back to its recommended value. There are scenarios where the battery voltage is low and if the inverter was on it would run but the voltage is too low and the firmware prevents the inverter from switching on.
  9. I noticed yesterday that the SCC heatsinks were considerably cooler and that the inverters became quiet when we were in float even though I was still drawing 2kW. I have 3000W of PV on the one inverter and 1500W on the other.
  10. My inverters are in our family room/TV room/office next to my desk. The inverters have never bothered me before - when someone used the microwave the fans would be noticeable but other that that the PC made more noise than the inverters. Now with the 2kW baseload I have during the day the inverters are 8 degrees cooler but irritatingly noisy.
  11. A DC contactor where the coil is closed via AC would be ideal NO would power off grid NC would power grid tie. ABB make a DC compliant contactor or you could use a ordinary contactor with a snuffing capacitor.
  12. Hi @wolfandy it works perfectly an switches immediately. Since I have not integrated the script into Node red yet I am using SSH at the moment at the appropriate times. I will after a while be able to see how much I am saving. When I flashed 73.00e I had a "jelly bowel" inducing moment where the flash failed and the inverter appeared to have been bricked. I re flashed again and the inverter came to life with myself being the only thing suffering from the ill effects of the failed flash. @Coulomb is there a version of the firmware that has the standby features of 73.00e and the fan algorithm of 72.70c? I find the fan noise now excessive.
  13. Ok finally I have it working wake.py One could include a loop to ensure you have an ACK but I'll leave that for the weekend. Thank you so much @Coulomb
  14. Lol yes in between all the madness I find I have a little development time for myself.
  15. Hmm @Coulomb I have been looking at your documentation and am not sure whether dynamic load control is implemented by 72.70c or not. I have found my USB to serial cable and can reflash to 73.00e but am a firm believer in "If it ain't broke do fix it" principle. How is the integer used in the MNCHGC0497/MNCHGC0498 pairing derived?
  16. The old PF 0.8 Axperts had a quiescent power use of about 50W - which would be 1200Wh per day. Perhaps the newer inverters are more efficient or the quiescent consumption is lower in bypass mode.
  17. I would have a change over switch an run solely on generator until solar/battery is restored. A Pylontech 3000 can charge at 34 A or roughly 1700 W. I charge my Pylontech (4 x 2000s) at perhaps half their rated maximum of 100A. I have a 1.2 kW pump that runs everyday and a 1500W geyser element that mops up any excess energy, so I probably charge at about 40 A for large parts of the day. I find mid summer the bank of Pylontechs charging at 90 A can ramp up their temperatures.
  18. These are a pair of PF0.8 models running LF1 72.70 C patched software. So reflashing with your latest firmware (73.00e) will enable these commands?
  19. After 5 years (yes one of those back burner projects) I am communicating with my Axpert using my own scripts. A Czech Axpert user, Josef Kriegelstein has a pair of commands MNCHGC1497 and MNCHGC1498 to cause the Axpert to go into standby mode and revert to normal. They look more like charging current commands. I have used them to no success, getting a NAKss response from the inverter. Anyone had any success getting a inverter to switch off. I have a pair of inverters and after 6pm there is not much sense having both running.
  20. Heroldts in Bloemfontein was importing Synerji inverters
  21. Just one question how did you extend the battery cables between the two battery cabinets? I am possibly getting one more Pylontech and my current cabinet is full.
  22. Beautiful setup - just a word of warning those Goodwe ES inverters should not be run on a generator. One use to have to read the manual carefully but I see it has changed and explicitly states no generators. This information was previously hidden in the troubleshooting section
  23. Thank-you Lindsay. I have written my own crc function to take into account the Axpert's idiosyncrasies and have fewer dependencies. After spending some time fiddling with Node Red and node.js I have developed an aversion of libraries and dependencies unless they are well written and documented. It appears Voltronic use a chipset that masquerades as a Cypress Semiconductor chip. From a little saunter on the web Cypress seem to disown VID 0665 PID 5161 which leaves most of us fumbling in the dark. The Python 2/3 changes how strings are handled does not help either. I prefer how Python3 handles strings with text and bytes being discrete but does give one a headache when you trying to get an officially undocumented chipset to work. Thank-you Lindsay for rolling several large boulders out my way. In the mean time I have dusted off my 30 year old programming skills. I hear a cacophony of laughter coming down the ether. I cut my teeth on Basic, Cobol and eventually a little bit of Pascal and DOS doesn't stand for Dark Outer Space. Since I am so rusty I usually write 2 lines of comments for every line of code. I cannot abide not understanding code I have written/copied and end up dissecting github code. This I suppose defeats the object of repositories but too many folk (myself included) borrow code from a different source with scant regard to its robustness. This is in no way a slight on Lindsay's contribution for which I am most grateful.
  24. About 4 years ago I installed an electric geyser to act as a dumpload. When my family is away I can get away without using gas. Hot water from geyser powered by PV and I use an electrical kettle in conjunction with a thermos, and cook on an induction plate. Now during lockdown I have my broom-flying mother-in-law to stay and in the interests of my own sanity have abandoned any ideas of trying to be frugal in our gas usage.
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