Jason Smit Posted November 8, 2019 Share Posted November 8, 2019 This problem is killing me. I really hope there is a solution. When my battery gets low, the inverter and the battery shuts down. Now the problem is that it does not charge while it is shut down. So while I am not at my farm house and battery runs low on a cloudy day, the entire system shuts down, charging stops and nothing works till I can switch the system on again. Anyone with ideas how I can bypass this? Surely there must be a setting for it to keep charging at the very least? Quote Link to comment Share on other sites More sharing options...
Jaco De Jongh Posted November 8, 2019 Share Posted November 8, 2019 2 hours ago, Jason Smit said: This problem is killing me. I really hope there is a solution. When my battery gets low, the inverter and the battery shuts down. Now the problem is that it does not charge while it is shut down. So while I am not at my farm house and battery runs low on a cloudy day, the entire system shuts down, charging stops and nothing works till I can switch the system on again. Anyone with ideas how I can bypass this? Surely there must be a setting for it to keep charging at the very least? HI Jason, welcome to the forum. A few questions: What type of batteries do you have and size of bank? What is the low cutoff setpoint on the inverter? How often do you experience low voltage condition? Quote Link to comment Share on other sites More sharing options...
Jason Smit Posted November 9, 2019 Author Share Posted November 9, 2019 Hi Jaco, Thank you for the quick reply. My response below: 1. I have 1 x Pylontech US2000 Plus battery 2. Low cutoff is at 42V 3. I live on a farm in Botswana and my load is just-just covered with this setup. I actually need another battery but still saving for that. So this happens about once a week, and normally when I am away from the farm. Half a cloudy day and the system bombs out. Quote Link to comment Share on other sites More sharing options...
Johandup Posted November 9, 2019 Share Posted November 9, 2019 This happened once to my system. I had to switch all the batteries off and on, one by one. I had to fiddle with the inverter (a 4kw hybrid Infinisolar) to get it going again. It tripped on overload the other day and a simple start got it going. Still doesn't know why. I need to replicate the scenario when I have time. Quote Link to comment Share on other sites More sharing options...
Jason Smit Posted November 9, 2019 Author Share Posted November 9, 2019 My problem is bit different. My system shuts down on low battery power, and then stops charging which means that everything stops. Until I restart the battery and the Inverter. Just does not seem right to me. Surely it was not designed like this. Quote Link to comment Share on other sites More sharing options...
Chris Louw Posted November 9, 2019 Share Posted November 9, 2019 @Jason Smit Try setting 29 ( battery low cut off ) on 47.5 volt like recommended by Pylontech . The batteries disconnect because of low battery voltage . When the battery is disconnected it can't be charged . If the setting 29 is changed from 42 to 47.5 the inverter will switch off but charging can still happen . Coulomb 1 Quote Link to comment Share on other sites More sharing options...
Jason Smit Posted November 12, 2019 Author Share Posted November 12, 2019 @Chris Louw Thanks a mil! I will try this. Quote Link to comment Share on other sites More sharing options...
Chris Louw Posted November 12, 2019 Share Posted November 12, 2019 @Jason Smit You can lower the battery cut off if you get a battery low alarm . Mine is set at 46 v and working fine . Are you running offgrid . Just keep in mind the inverter must switch off first . The BMS of the Pylons disconnect at 44.5 v Quote Link to comment Share on other sites More sharing options...
RikH Posted November 12, 2019 Share Posted November 12, 2019 1 hour ago, Chris Louw said: @Jason Smit You can lower the battery cut off if you get a battery low alarm . Mine is set at 46 v and working fine . Are you running offgrid . Just keep in mind the inverter must switch off first . The BMS of the Pylons disconnect at 44.5 v I wouldn't go that low, it will shorten the lifespan off the battery. Stay on the figures like Chris posted above and you'll be fine. Quote Link to comment Share on other sites More sharing options...
@Mak Posted June 16, 2020 Share Posted June 16, 2020 Can anyone please assist with the ideal setting for my setup which comprises: 1. 5kV Mercer Inverter 2. Twelve 410w solar panels 3. Two pylontech batteries- s3000 3.5kV My system switches off for a short period (30 secs) when load is too high for battery /solar affecting all appliances and wifi connections. Is there a setting that can avoid these resets. Esentially i want to use solar and battery when available and switch to Eskom when load is too high for solar and or battery. i would really appreciate your guidance or something similar to the table above. Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 17, 2020 Share Posted June 17, 2020 9 hours ago, @Mak said: My system switches off for a short period (30 secs) when load is too high for battery /solar affecting all appliances and wifi connections. Is there a setting that can avoid these resets. It sounds like you have bypass on overload not turned on (setting 23 should be bYE, bypass enable). I have no idea why the default setting is to turn that off. 9 hours ago, @Mak said: something similar to the table above My version of the above table has a few crossings out: Quote Link to comment Share on other sites More sharing options...
@Mak Posted June 17, 2020 Share Posted June 17, 2020 Thank you very much for this. My setting on Program 23 was indeed at byd. When changed to bye it immediately went to bypass. It looks like I need an additional invetor to manage larger loads. when changing the programs I noted there are a number of programs that are blocked and can not be changed eg 28. I am thinking of getting another Mercer 5 kV to install in parallel. The current Inveter is running on 6 mm cable would this be adequate for 2 inviters or would I need to change the cable to 10 mm? Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 18, 2020 Share Posted June 18, 2020 17 hours ago, @Mak said: It looks like I need an additional invetor to manage larger loads. If you're happy with the occasional ≥10 minute switches to bypass mode, then there is no need. You'd also need to add more battery modules; two Pylontech US3000s are happiest at 2 x 37 = 74 A max, or about 3500 W, so they're not even enough for one inverter if run continuously near maximum rated power. Of course, that would be very rare, so I don't believe that's a problem at present. 17 hours ago, @Mak said: I noted there are a number of programs that are blocked and can not be changed eg 28. No, 28 is one that can only be changed while the power switch is off. Either be quick with the setting change, or ensure that there is a charging source (AC-in or OV-in). You should change yours to SnG unless or until you parallel with another inverter. Strange problems have been traced to using PAL when there is only one unit. 17 hours ago, @Mak said: The current Inveter is running on 6 mm cable would this be adequate for 2 inviters or would I need to change the cable to 10 mm? Technically, 6 mm² cable is only good for 38 A (run in conduits, no special conditions). That's just under 9 kVA. So two inverters running continuously near 5 kVA each (which might be near 4 kW each depending on the power factor of your load) could overload your AC wiring. But again, that's likely to be so rare that I would not worry about it. I run 2 x 4 mm² myself, joined at the switchboard end. Quote Link to comment Share on other sites More sharing options...
@Mak Posted June 21, 2020 Share Posted June 21, 2020 Thank you for the above input, much appreciated. Quote Link to comment Share on other sites More sharing options...
@Mak Posted June 21, 2020 Share Posted June 21, 2020 Ocassionally my Inveter flashes error 7 and beeps. What is a reasonable period to operate at loads above inveter limit. Also at what point does one consider increasing to another inverter Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 21, 2020 Share Posted June 21, 2020 8 hours ago, @Mak said: What is a reasonable period to operate at loads above inveter limit. I have no idea. When my inverter (back when I was using only one) overloaded, it quickly switched to line mode, solving the problem. Quote Link to comment Share on other sites More sharing options...
@Mak Posted June 21, 2020 Share Posted June 21, 2020 I have changed section 23 to bypass so mine also switches to line. But the load is above my load capacity so it continues to beep even when connected to utility. Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 21, 2020 Share Posted June 21, 2020 (edited) 18 hours ago, @Mak said: But the load is above my load capacity so it continues to beep even when connected to utility. Ah, now I get it. [ Edit: no, I don't. See this post below. ] Sorry to be so slow. I'd say that this would be a good indication that you need to run fewer loads off the inverter, or add another inverter. But with a second inverter, you'll need more battery and probably more PV. [ Edit: I no longer agree with this statement; again see the post below. ] Edited June 22, 2020 by Coulomb Quote Link to comment Share on other sites More sharing options...
introverter Posted June 21, 2020 Share Posted June 21, 2020 (edited) 4 minutes ago, @Mak said: I have changed section 23 to bypass so mine also switches to line. But the load is above my load capacity so it continues to beep even when connected to utility. one option can be to manage the peak loads better (don't boil the kettle while the washing machine is heating water while someone is using the vacuum cleaner).. as already indicated by coulomb Edited June 21, 2020 by introverter acknowledge coulomb Quote Link to comment Share on other sites More sharing options...
@Mak Posted June 21, 2020 Share Posted June 21, 2020 17 minutes ago, Coulomb said: Ah, now I get it. Sorry to be so slow. I'd say that this would be a good indication that you need to run fewer loads off the inverter, or add another inverter. But with a second inverter, you'll need more battery and probably more PV. What would be the impact if I ran two Inveters on my current battery and PV set up. At this stage I am looking to get the higher loads when in utility mode. Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 21, 2020 Share Posted June 21, 2020 1 hour ago, @Mak said: What would be the impact if I ran two Inveters on my current battery and PV set up. This isn't clear to me. The battery could disconnect through overload, perhaps with PV running at near full bore, and I don't know how the inverters would react. Not well, I suspect. Quote Link to comment Share on other sites More sharing options...
@Mak Posted June 21, 2020 Share Posted June 21, 2020 26 minutes ago, Coulomb said: This isn't clear to me. The battery could disconnect through overload, perhaps with PV running at near full bore, and I don't know how the inverters would react. Not well, I suspect. Apologies if it’s a bit vague. My system goes to bypass when o draw large loads. But it sets off the alarm ( I presume because the load capacity of the Inveter is running above 100% even when using the utility). My aim is to avoid by pass by adding an additional inverter hence more load capacity. I realize there is a maximu due to limited battery bank size and number of panels. But at least with 10 kV capacity the system will only bypass when there is a load greater than 10 KV instead of the current 5 kV. This way I can maximize the PV feed. Is that reasoning ok? Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 21, 2020 Share Posted June 21, 2020 1 hour ago, @Mak said: But at least with 10 kV capacity the system will only bypass when there is a load greater than 10 KV instead of the current 5 kV. This way I can maximize the PV feed. Is that reasoning ok? No. At above around 4 kW total (2 kW per inverter), the inverters will try to stay in battery mode, the battery will eventually disconnect, and I don't know what will happen. The >4 kW of load power has to come from somewhere, and with two inverters, it won't be coming from the utility. There won't always be 3-4 kW of PV to help out. The inverters don't and can't know what the maximum capacity of the battery is; they assume it can supply the 100+ A required. Some models can run without a battery, but I think that even those that can run without a battery won't cope with a battery present, then suddenly taken away because the BMS disconnects the cells to save them from over-discharge. Quote Link to comment Share on other sites More sharing options...
@Mak Posted June 21, 2020 Share Posted June 21, 2020 1 hour ago, Coulomb said: No. At above around 4 kW total (2 kW per inverter), the inverters will try to stay in battery mode, the battery will eventually disconnect, and I don't know what will happen. The >4 kW of load power has to come from somewhere, and with two inverters, it won't be coming from the utility. There won't always be 3-4 kW of PV to help out. The inverters don't and can't know what the maximum capacity of the battery is; they assume it can supply the 100+ A required. Some models can run without a battery, but I think that even those that can run without a battery won't cope with a battery present, then suddenly taken away because the BMS disconnects the cells to save them from over-discharge. From the above statement is it correct to infer that a load above 2kw will trigger bypass to utility per Inveter. If this is correct then I assume that with two in parallel Inveter that capacity to switch to by pass will be doubled to 4 kW. I am surprised that you say utility will not be able to provide the additional required load Quote Link to comment Share on other sites More sharing options...
Coulomb Posted June 22, 2020 Share Posted June 22, 2020 (edited) 12 hours ago, @Mak said: From the above statement is it correct to infer that a load above 2kw will trigger bypass to utility per Inveter. No, that depends on the instantaneous strength of your battery (SOC, time of day, temperature), and your settings, especially setting 12 (back to grid voltage), and sometimes setting 29 (low DC cutoff voltage). I was trying to say that the danger zone is between 2 and 4ish kW (depending on load power factor) for a paralleled pair of inverters; it's not high enough to switch to utility (that's the problem; utility would save it), so the inverters stay with battery, the battery BMS will disconnect (may take some time, but it won't allow that sort of power continuously), and that's when the damage is likely to happen (if at all). I had a quick re-read of the firmware, and it seems to me that (at least in version 73.00 which I have studied the most), fault code 07 never happens in bypass/line mode, so only battery mode. So it relates only to the inverter power and/or VA limits (I think both are checked). So I take back my "now I get it" comment. I note that warning code 07 happens at 110% or more overload for 500ms, and fault code 07 with: 110% power for 10.5 seconds, or 150% power for 5.5 seconds, or 200% power for 200 ms (0.2 seconds). So I'm confused as to why switching to bypass doesn't solve your problem, saving the need to buy and extra inverter, and the battery and likely PV that needs to go with that. Edit: Duh. I now realise that warning code 07 (as opposed to fault code 07) can happen in bypass/line mode. In this case, it is telling you that it can't go back to battery even if settings allowed, because of the present load. So in bypass/line mode, warning code 07 isn't a big concern, and can be safely ignored. Edited June 22, 2020 by Coulomb introverter 1 Quote Link to comment Share on other sites More sharing options...
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