Chris Knipe

Hi All, I have a 10kWh self built, which is starting to swell and I am looking now for replacements. 1) SunSynk 8kW inverter 2) I want about 20kWh - the batteries must be rackmountable, not wall mountable 3) I am looking at the PylonTech UF5000 (5kW) or Deye 5kW (both can talk to the SunSynk as far as I am aware). I am starting to see more and more posts on PylonTech batties swelling, so I am having a bit of a debate on my side now. Do I go for the Deye, do I go for the PylonTech, do I look at something else? My main concern is that it must be rack mountable, and the BMS must talk to the SunSynk without issues and/or complications. Also as a side note. How does one safely dispose of lithium cells? Thanks,

Quick Q please... SunSynk 5KW... What lug sizes for the battery terminals? M8?

Hi Guys. Quick question please. 1) As far as I understand, SANS 10142 wants your solar panels earthed, and bonded to it's own dedicated earth spike (PE). The reasoning behind this is that IF lightning strikes the panels, the path to earth does not touch the rest of the electrical installation (your PV panels are essentially isolated, provided your fuses can withstand a lightning strike, of course). 2) When you add surge protection to the PV however... Does the earth for the surge protection go to the PE (panels' ground spike), or can the earth go to the electrical installation? As I see it, the surge protector needs to be earthed to the same spike as the solar panels, in order to keep the isolation, right? Reasoning for asking is that I have a fairly longish cable run for a upcoming monster installation. I am trying to avoid running copper, as it would be significantly cheaper to just sink an earth spike... But if I have to run copper for the surge protectors in any case.... Well... Hoes I guess?

Sorted root@cm4-can:~/src# modbus -s 1 -b 9600 -p 1 -P n -v /dev/ttySC0 183 Parsed 0 registers definitions from 1 files Serial port /dev/ttySC0. Parameters: 9600 baud, 1 stop bit(s), parity: N, timeout 5.0s. → < 01 03 00 b7 00 01 34 2c > ← < 01 03 02 14 de 37 1c > 7 bytes ← [5342] 183: 5342 0x14de root@cm4-can:~/src# python3 test.py MinimalModbus debug mode. Create serial port /dev/ttySC0 minimalmodbus.Instrument<id=0x7f9b27dd90, address=1, mode=rtu, close_port_after_each_call=False, precalculate_read_size=True, clear_buffers_before_each_transaction=True, handle_local_echo=False, debug=True, serial=Serial<id=0x7f9b27dd00, open=True>(port='/dev/ttySC0', baudrate=9600, bytesize=8, parity='N', stopbits=1, timeout=1.0, xonxoff=False, rtscts=False, dsrdtr=False)> MinimalModbus debug mode. Will write to instrument (expecting 11 bytes back): 01 03 00 B7 00 03 B5 ED (8 bytes) MinimalModbus debug mode. Clearing serial buffers for port /dev/ttySC0 MinimalModbus debug mode. No sleep required before write. Time since previous read: 6868903.28 ms, minimum silent period: 4.01 ms. MinimalModbus debug mode. Response from instrument: 01 03 06 14 DC 00 62 03 12 D2 91 (11 bytes), roundtrip time: 0.0 ms. Timeout for reading: 1000.0 ms. [5340, 98, 786]

Sorry to revive an old topic.. root@cm4-can:~/src# python3 test.py MinimalModbus debug mode. Create serial port /dev/ttySC0 minimalmodbus.Instrument<id=0x7fb5ac3d90, address=1, mode=rtu, close_port_after_each_call=False, precalculate_read_size=True, clear_buffers_before_each_transaction=True, handle_local_echo=False, debug=True, serial=Serial<id=0x7fb5ac3d00, open=True>(port='/dev/ttySC0', baudrate=9600, bytesize=8, parity='N', stopbits=1, timeout=1.0, xonxoff=False, rtscts=False, dsrdtr=False)> MinimalModbus debug mode. Will write to instrument (expecting 11 bytes back): 01 03 00 B6 00 03 E4 2D (8 bytes) MinimalModbus debug mode. Clearing serial buffers for port /dev/ttySC0 MinimalModbus debug mode. No sleep required before write. Time since previous read: 5780045.46 ms, minimum silent period: 4.01 ms. MinimalModbus debug mode. Response from instrument: 0D 11 C5 2C 0E 04 10 00 00 17 B4 (11 bytes), roundtrip time: 0.7 ms. Timeout for reading: 1000.0 ms. Traceback (most recent call last): File "/root/src/test.py", line 13, in <module> result = device.read_registers(registeraddress=182, number_of_registers=3) File "/usr/local/lib/python3.9/dist-packages/minimalmodbus.py", line 904, in read_registers returnvalue = self._generic_command( File "/usr/local/lib/python3.9/dist-packages/minimalmodbus.py", line 1245, in _generic_command payload_from_slave = self._perform_command(functioncode, payload_to_slave) File "/usr/local/lib/python3.9/dist-packages/minimalmodbus.py", line 1329, in _perform_command payload_from_slave = _extract_payload( File "/usr/local/lib/python3.9/dist-packages/minimalmodbus.py", line 1867, in _extract_payload raise InvalidResponseError(text) minimalmodbus.InvalidResponseError: Checksum error in rtu mode: '\x17´' instead of 'i4' . The response is: '\r\x11Å,\x0e\x04\x10\x00\x00\x17´' (plain response: '\r\x11Å,\x0e\x04\x10\x00\x00\x17´') Not sure why, but it seems that the CRC Validation is failing?

Can't remember to be honest. if I did say mosfets initially then yes I changed it through one of the edits. Q30, Q29, Q27, and Q28 are IGBTs (Insulated-gate Bipolar Transistor), not MOSFETs. Provided there's no other damage, I should be good by just replacing all 4 IGBTs.

Ok, so my Axpert just had it's last Error 51... Out of the blue, nothing out of the ordinary, one big bang, error 51, and all power off (first one in over a month too). Inverter blew so bad that it even tripped that AC Circuit Breaker (40A) in the DB board. Strangely, the Inverter's own circuit breaker didn't pop. Bypassed, removed the inverter and opened her up. I've lost Q28 and Q27 (DC/DC IGBTs). The cap in front of it has been broken off the PC board by the explosion. These are all DC/DC IGBTs. I'm not sure whether this is the CAUSE, or rather a symptom of the result of the error. The IGBTs are repairable (covered in the service manual) provided there isn't too much other damage, but the question remains as to what is causing this. Me personally, I will never in my life buy an Axpert like inverter again. Not because of the strange error, but the fact that it's completely unknown, and undocumented... Even the manufacturer just pulls up their shoulders saying "sorry, if it's not in the manuals, we can't help you". Guess it's time to start saving for some Victrons. Those getting Error 51s (I know I am not the only one), please, tread carefully... Just resetting / restarting, isn't the solution.

I guess they misrepresented the facts then... A direct quote from their email to me: "We had a customer who’s unit blew 3 times between 12h00 and 13h00, someone suggested that it may be caused by solar bursts causing the excess wattage and voltage to go into the inverter. We reduced from 3 panels in series to 2 panels in series and so far so good." Ok... So, someone's talking BS then. Probably FCS as he pretty much tried to sell me a new inverter before even attempting to assist with my problem.... Typical South Africa. You are misunderstanding the facts... ANY PV generation, will be SIGNIFICANTLY less in the morning, vs. during mid day. That is why at night time, we have ZERO VOLTS on our panels, there is ZERO SUN. As the day starts and the wonderful sun starts rising, we , the PV panels, generate MORE AND MORE POWER because we get MORE AND MORE SUN! ANY PV graph, will CLEARLY indicate how the days' generation starts at pretty much 0W (watts, which is the result of Amps & Volts). As the day progresses, the Watts being generated, becomes MORE AND MORE up to a point, determined by the amount of SUNLIGHT the panels receive. Yes, cold weather / warm weather has an effect. I am not denying this. The FACT remains, ANY PV panel, will generate SIGNIFICANTLY more power at noon on a sunny day, vs. at dusk and dawn. Please, don't tell me otherwise. At noon, when the sun is at it's highest, my VOLTS are through the roof. It's through the roof because I have 3 panels in series, where I should only have two in series. Because I have three in series, my volts are high, and my amps are low. The inverter does not like this, because the high amount of volts, exceeds the limits of the inverter. Moving the panels and putting only 2 in series, I can REDUCE the volts, but also INCREASE the amps. Thus, I still generate the same amount of watts, but with a lower voltage, and a higher amperage, which is more in line and acceptable to the limits and specifications of the inverter. Again, please go and look at ANY PV Generation graph, and by all means, show me ONE graph, where the WATTS GENERATED IN THE MORNING is more than the watts generated at NOON. I am not disputing that. But until you, or someone else can DEFINITIVELY TELL ME what is broken, what the hell am I suppose to do and think? I am not taking my entire inverter, and replacing components left, right, and center, because of an ASSUMPTION. The very service manuals, state that a certain measurement over a certain mosfet, is indicative of a FAILED mosfet. Yet, people here believe otherwise? If I can't even trust the manufacturers OWN DOCUMENTATION, who am I supposed to trust? Everyone has an opinion, everyone believes their opinion is right. The fact of the matter is no one knows.

Perfect, thank you @Chris-R - that graph is almost EXACTLY what I expected to see. This is exactly what I was after. Yes generation in winter is expected to be less, however, I still feel that it can be justified (some PV, is better than NO PV at all in the case that there's no North facing space available). You can (or I can at least given the space I have available) also compensate for the lower generation in Winter by over specing the system and putting a few more panels than what is needed on. You can also if winter is a potential problem, do more on the west side with even more panels, and hope that the afternoon sun on the west side will be sufficient to carry the load and give enough to charge the batteries. That is all things that one can address with the proper and adequate math however. @plonkster yep - well aware of what quattro means. Well aware of how Victron's Quattros work as well

So spoke to Full Circle Solar as @Jaco de Jongh suggested. Except for the normal "ventilation, be sure it's grounded, surge protection, etc" something interesting came out... They had a fair amount of customers, suffering from Error 51s. ONLY during 12:00 and 13:00 (Note, they are in JHB, I am in CPT). In ALL these cases, they reduced the PV generation on the Inverter and the issue went away, immediately. Never to return. This is caused by surges on the PV side (as I have originally suspected), it is caused by surges in wattage and voltages due to extreme solar conditions. I am 6V away from Voc in a NORMAL day. On a day with extreme sun, I will MOST DEFINITELY exceed Voc. It's nothing for 9 x 300W panels, to fluctuate and generate that additional 6V and by doing so generate an overload / surge condition on the Inverter as it is exceeding the max ratings of the inverter. It also explains why it ONLY happens when it's hot, warm and sunny. Not quite sure when I'll get to this, as the re-wiring required is extensive, but I will be moving from 3x3x300W to 2x5x300W to reduce my Volts & increase my Amps on my PV supply. That should solve my issues.... There's no damage, there's nothing broken. This is WEATHER together with my PV being EXTREMELY close to Voc, and me generating too much power over PV on hot warm days for the Inverter to handle. Nothing more, nothing less.

Thanks @plonkster It's not a lot south east. I'd say more east/west than anything. Both sides get plenty of sun during the winter and summer months. Been keeping my eyes on it for a few years now. I'm still trying to get my head around Victron and all their offerings yes. I'm more than likely looking at 2 x Blue Solar and 1 x Quattro given the loads I have in mind (couple of Pylons perhaps for storage). As far as I understand, the Quattro will control the Blue Solars yes.

Hi Guys, So I figured I'd rather start a new thread. We all know what happened and I think I am at the point where I am going to write my Axpert off - permanent by-bass has been wired into the DB. I was intending to upgrade the system *significantly* in any case... Thankfully now, I have decided to look at Victron and I am impressed - it's bound to be a better choice than the Axperts / Infinity / etc. One of the big obstacles I've had in the past with my current system, was that I do not have a lot of north facing roof space. It doesn't matter what you do or how you look at it, there simply isn't space and you can't magically invent space either. My house's roof orientation is unfortunately South East/ North West, but I have a LOT of South East / North West space available. Looking at Victron's BlueSolar MPPT's now, I see that they can be paralleled? Whilst I understand you will loose some efficiency as only half the panels will work in the morning, and the other half will work in the evening (and both should work during mid-day hours)... Would it work to connect two of these units in parallel and have one charger on the East facing panels, and another on the West facing panels? I am confident they will get more than sufficient sunlight, I can put up more than sufficient panels. I can easily max out a 150/70 or 150/80 on each side of my roof I reckon in terms of max PV input power... The idea here is to generate and store as much as possible, to go off grid completely. I haven't crunched the numbers yet though so the discussion is theoretical at this stage. I am more than likely going to go a bit big and look in the 6kW to 8kW region for PV though (currently have 3kW installed on my grid-tied system). Yes, I know it won't be as efficient. Yes, I know I will need more panels. Yes, I will more than likely need two Chargers. Technically speaking, no reason why it wont work though, right?

Again I am not arguing, just stating... Page 15, in terms of testing D32/D35/D33/D34, they explicitly say that R90/R99/R94/R97 must be removed for the test (they do that for quite a few tests, granted it's all diodes that is being tested). Why state on one test that components must be removed for the test to be accurate, but they don't state it on the other tests? I know too little here other than to follow the instructions of the manual and the instructions in the manual does not state that components must be removed (yet, I know what @plonkster is saying may very well hold true with my limited understanding of micro electronics). I'm no electrical engineer though. MOVs can't be tested at all either from what I am seeing. Oh Error 51, why must you have entered my life... I'm baffled as to how few occurrences, and now little knowledge / information is out there about this specific error. It's almost like you've hit one in a million here...

Im actually also very curios, why virtually every single error condition (EXCEPT Error 51) and this includes replacing the MOVs too, is covered in the service manuals...

State at last actual usage (with supply, load, PV & batteries) - worked, 100% except for the occasional Error 51 (2 or 3 times per day, only during day time, online during warm ambient temperatures). I am by no means an expert here either, so please rest assured your input and feedback is appreciated. Batteries - I find this strange as well. There is HUGE arching when the batteries are connected (I use an external 100A fuse for a disconnect). Even with the inverter switched off (nothing connected to supply, PV, or load), there is arching when connecting the batteries. This never used to happen before. The batteries are also EXTENSIVELY cooking, which never happened before. Yesterday, I connected batteries & PV and switched the inverter on. Supply & load was disconnected as this was still by-passed. According to the Inverter's panel, there was a load of some 300W being pulled, yet nothing was connected to the inverter at all. At about 9PM after sun set and PV didn't generate any power, I actually got battery low alarms, and the inverter shut down because the batteries was flat. So, what was pulling loads, and why did the batteries drain? MOVs... Anyway to test them? Again, I am not saying that there is / isn't anything wrong with them (I don't have the knowledge to make that call), but I also don't want to just blindly go replace things and potentially, break things even further in the process... Re Resistors & Transistors - they where tested. Some faulty, some not. I figured as they recommend in the service manual to replace all MOSFETs in the case of one being faulty, I may just as well replace all the transistors too. Transistors are cheap enough to just replace them. Given the extent of my testing though, the list of components (potentially) to replace is becoming too significant for me personally at this stage. For me faulty means not getting a reading as it is suggested in the service manual. More than that I don't know unfortunately. So if the service manual tells me I must get a SD of 0.43V on Q14, and I don't get it - I have no reason to believe other than that Q14 is faulty. Not saying that YOU are wrong of course I'm saying that if you are right, the service manuals is wrong...