38 minutes ago, Krokkedil said:

I have tried all the combinations of settings. The system always draw some power from the batteries. 

That's by design. Not much you can do about that. 

6 minutes ago, Rclegg said:

Sure  (Note I switched it back to Utility as I need to keep battery topped up for load shedding later )

Thanks

If you manually change to Utility, please be aware that the ICC settings from your Battery Settings page are still active in the background - which means that ICC will probably switch you back to SBU as your SOC is higher than your 'Back to Grid' SOC setpoint. If you want to manually override your mode setting, you need to first disable 'Use SOC for Control' and save (and then later re-enable them once you want ICC to take over again)

Prior to 12h15 the behavior is normal. When you switched on a large load around 12h00, the inverter briefly drew on the batteries. This is due to the MPPT not being able to ramp as quickly as your load increased (which is normal). You then maxxed out your PV production for a short while, but as this was still not sufficient to drive the loads the inverter continued to draw from the batteries (but a lesser amount). Once your load dropped again, excess PV was used to recharge your batteries. Once they were full again, PV was throttled to the amount required to drive your loads.

But I do not understand why your PV around 12h15 suddenly dropped to 0W and the inverter only ran on Battery. Did you have cloud cover at that point?

Okay, so I have noticed something interesting. 

If the house load is high, like 2.5Kw - then the inverter uses the solar to power the loads. But normal load like 800 or so, then it uses batteries. I wonder if this is due to not enough volts from the panels? Thinking I might see if 2S6P works? 

Just now, Rclegg said:

If the house load is high, like 2.5Kw - then the inverter uses the solar to power the loads. But normal load like 800 or so, then it uses batteries. I wonder if this is due to not enough volts from the panels? Thinking I might see if 2S6P works? 

I do not know enough about the MPPT side of the Axpert. Maybe @Coulomb can help with that?

2 minutes ago, wolfandy said:

Thanks

If you manually change to Utility, please be aware that the ICC settings from your Battery Settings page are still active in the background - which means that ICC will probably switch you back to SBU as your SOC is higher than your 'Back to Grid' SOC setpoint. If you want to manually override your mode setting, you need to first disable 'Use SOC for Control' and save (and then later re-enable them once you want ICC to take over again)

Thanks, that I did not know, very helpful! 

3 minutes ago, wolfandy said:

Prior to 12h15 the behavior is normal. When you switched on a large load around 12h00, the inverter briefly drew on the batteries. This is due to the MPPT not being able to ramp as quickly as your load increased (which is normal). You then maxxed out your PV production for a short while, but as this was still not sufficient to drive the loads the inverter continued to draw from the batteries (but a lesser amount). Once your load dropped again, excess PV was used to recharge your batteries. Once they were full again, PV was throttled to the amount required to drive your loads.

But I do not understand why your PV around 12h15 suddenly dropped to 0W and the inverter only ran on Battery. Did you have cloud cover at that point?

No there was zero cloud cover at that point. Not sure what it is doing there either. 

10 minutes ago, Rclegg said:

Okay, so I have noticed something interesting. 

If the house load is high, like 2.5Kw - then the inverter uses the solar to power the loads. But normal load like 800 or so, then it uses batteries. I wonder if this is due to not enough volts from the panels? Thinking I might see if 2S6P works? 

How are your panels configured at the moment? Be careful to not exceed the MPPT limits on the inverter with regards to voltages and amps.

3 minutes ago, Rclegg said:

No there was zero cloud cover at that point. Not sure what it is doing there either. 

Then I am also at a loss... Maybe @Coulomb will have an idea as to what might cause this behavior.

One last question: When your PV ramped up again around 12h23 - did this happen by itself or did you switch the inverter to Utility in the meantime?

Is this your Inverter specs:

Then your ICC MPPT voltage values seem very low to me...

That could explain why the MPPT is struggling

 

1 minute ago, francois said:

How are your panels configured at the moment? Be careful to not exceed the MPPT limits on the inverter with regards to voltages and amps.

3 Strings of 4 Panels  Inverter limit is 450VDC

1 minute ago, wolfandy said:

Then I am also at a loss... Maybe @Coulomb will have an idea as to what might cause this behavior.

One last question: When your PV ramped up again around 12h23 - did this happen by itself or did you switch the inverter to Utility in the meantime?

I think I turned the pool pump on to use the extra PV energy. 

Every time our house cleaner turns the hoover on, inverter switches rot PV and uses 2.2kw of the generation. Im confused. 

Just now, francois said:

Is this your Inverter specs:

Then your ICC MPPT voltage values seem very low to me...

That could explain why the MPPT is struggling

 

 

That would be correct yes. MPPT hovers at around 160 or so odd. Maybe I need to double the voltage by going to 2  strings of six so around 300 volts?

1 minute ago, Rclegg said:

 

That would be correct yes. MPPT hovers at around 160 or so odd. Maybe I need to double the voltage by going to 2  strings of six so around 300 volts?

Sounds better. I know my MPPT derates at voltages below 250V

Remember to disconnect the MPPT from the panels before making changes to the wiring on the roof. 

23 minutes ago, Rclegg said:

Thinking I might see if 2S6P works? 

6S2P ? What are the panel specs?

Edited August 19, 20205 yr by francois

5 minutes ago, Rclegg said:

I think I turned the pool pump on to use the extra PV energy.

Have a look at the add-on Advanced Power Managed (APM) from ICC if you want to automate that (using Sonoff Basics). I am using that to automatically switch on my pool pump when I have sufficient excess energy and to switch if off when PV drops. Below you can see that it automatically switched off my pool pump (load dropped) when I had a cloud cover around 12h45 and switched it on again around 13h05 when the clouds had moved on

8 minutes ago, francois said:

Sounds better. I know my MPPT derates at voltages below 250V

 

Hmm I think we are on to something now. Each time I increase the load in the house, it goes to solar as expected. But load has to be over 2kw 

7 minutes ago, francois said:

Remember to disconnect the MPPT from the panels before making changes to the wiring on the roof. 

Noted. Will be turning off the combiner box. 

 

4 minutes ago, francois said:

6S2P ? What are the panel specs?

 

Yeah 2 strings, 6 panels each. That should get me to 10amp per string and 300 volts - more or less. Each panel is around 49 volts 

 

3 minutes ago, wolfandy said:

Have a look at the add-on Advanced Power Managed (APM) from ICC if you want to automate that (using Sonoff Basics). I am using that to automatically switch on my pool pump when I have sufficient excess energy and to switch if off when PV drops. Below you can see that it automatically switched off my pool pump (load dropped) when I had a cloud cover around 12h45 and switched it on again around 13h05 when the clouds had moved on

 

Thats exactly what I would like to do when this whole thing is working. Thanks for the info. 

1 minute ago, Rclegg said:

 

Hmm I think we are on to something now. Each time I increase the load in the house, it goes to solar as expected. But load has to be over 2kw 

Noted. Will be turning off the combiner box. 

Yeah 2 strings, 6 panels each. That should get me to 10amp per string and 300 volts - more or less. Each panel is around 49 volts 

Sounds good 👍

 

Also keep the MPPT amp rating in mind:

 

3 minutes ago, francois said:

 

Also keep the MPPT amp rating in mind:

 

 

Hmm, I might be exceeding that with the current configuration? As the panels would give 30Amp in current config. Will be changing the panels config over today. 

With two string, max AMP on those panels will be or so I believe. 

The panels are the CanadianSolar 410W Poly ones. 

Just now, Rclegg said:

 

 As the panels would give 30Amp in current config. Will be changing the panels config over today. 

 

Damn! 🤣Good idea to change the config before it goes up in smoke.

Sorry might have missed it along the way but did you post the firmware version and display version for the inverter ? 

11 hours ago, Rclegg said:

I wonder if this is due to not enough volts from the panels? Thinking I might see if 2S6P works? 

Of course you mean 6S2P (6 panels in series, two such strings in parallel). I don't think it could cause this issue. However, I will note that there is a maximum of 18 A on the panel current, and your panels have an Imp of about 10.5 A. That's assuming I looked up the right Canadian Solar 410 W panels; there are so many these days. So 3P as you have now is over 30 A, way over what the inverter is specified at. There have been reports of problems with PV that only had Imp of 20 A, so 2 strings is definitely better than 3 for this model.

They seem to be very strict on the 18 A maximum; I have no idea why. You'd think that the control circuit would just limit the current to a maximum of 18 A, and the occasional overshoot should not cause much of a problem. But it seems that these overshoots can cause hardware failure, sometimes spectacularly so (e.g. burned and charred SCC).

It's a shame that the progression of panel sizes is making it hard to fit a set of these latest monster panels to these inverter-chargers.

Edited August 19, 20205 yr by Coulomb
expand on 2P

33 minutes ago, Blowdart18 said:

Sorry might have missed it along the way but did you post the firmware version and display version for the inverter ? 

71.80

 

21 minutes ago, Coulomb said:

Of course you mean 6S2P (6 panels in series, two strings). I don't think it could cause this issue. However, I will note that there is a maximum of 18 A on the panel current, and your panels have an Imp of about 10.5 A. That's assuming I looked up the right Canadian Solar 410 W panels; there are so many these days. So 3P as you have now is over 30 A, way over what the inverter is specified at. There have been reports of problems with PV that only had Imp of 20 A, so 2 strings is definitely better than 3 for this model.

They seem to be very strict on the 18 A maximum; I have no idea why. You'd think that the control circuit would just limit the current to a maximum of 18 A, and the occasional overshoot should not cause much of a problem. But it seems that these overshoots can cause hardware failure, sometimes spectacularly so (e.g. burned and charred SCC).

It's a shame that the progression of panel sizes is making it hard to fit a set of these latest monster panels to these inverter-chargers.

 

Thanks for your input, much appreciated. We are reconfiguring the panels as we speak to be 6 Panels in 2 strings, yes. If this isn't the cause of the issue, do you have an idea why it won't pick up loads that are low? If my load is 2kw, the inverter normally goes to solar. At 800watt load, it goes to battery. 

37 minutes ago, Blowdart18 said:

Sorry might have missed it along the way but did you post the firmware version and display version for the inverter ? 

Display version - where do I find that?

Right, it seems we have success! 😀

The MPPT was definitely not happy at under 180v. Load has been low and the inverter has stayed on Solar! 

Panels are now in two series of 6. Which seems to be the ticket. 

 

The graph also looks a lot better and more stable. The heavy load at the end is because someone turned on the kettle and there was not enough PV generation for that. I know its at the limit of the Pylontech - will be getting another pylon at the end of the month. 

 

Thank you every one for all the input and help. IO really appreciate it and learnt a lot out of the system, 

@wolfandy - Can I PM you at some point to see how you did the pool setup? 

 

Now to try get the battery to charge to 100% before load shedding comes by tonight.