Hello all,

Hoping for some assistance on an issue I'm experiencing.

 

Issue : Constant switching between Battery and PV and then eventually to Grid.

During sunset I get constant switching. Inverter shows tiny wattage coming from the PV (as low as 2w) and the inverter switches constantly to battery and then back to PV. This goes on for a while till the sun completely goes down and there is zero wattage coming from the panels and the inverter does what it is supposed to do and moves to Grid eventually.

 

 

Couple questions:

Is there any way to resolve this and set a threshold - as an example to set the inverter to switch from PV to battery if the wattage is less than a certain limit?

The Axpert type inverter I use has the following model number on the sticker : MPS 3KVA-60. Is there perhaps some way to update the firmware if possible?

Link to the exact inverter :

https://shop.thesunpays.co.za/collections/axpert-inverters/products/3kva-2-4kw-80a-axpert-type-pure-sine-wave-inverter-single

 

System compromises of the following:

Axpert type MPS 3KVA-60 inverter

Pylontech UP2500 

3x JA Solar 490W Mono PV Panels

 

Set to SOL - this works perfectly for my needs. Essential loads wired through Sub-DB utilizes power from the panels from 9am - 6pm. 

Thanks for any assistance offered.

 

You can check setting

13 (Setting voltage point back to battery mode whenselecting “SBU priority” or “Solar first” in program 01)  

and try to put it at the maximum setting of ful, so the battery must be full before it will switch back to solar and battery?  This would mean that in the late afternoon it would be less likely to switch back to battery, due to the low solar input and its porobably still filing the battery?

 

 

What setting do you have it on during the day? 

When you say its constantly switching; do you mean that the mode is constantly switching (From SBU, to SOL, to grid) for example? or that you are simply using battery during the day? 

Could you provide a graph of your PV generation VS consumption if you have something like that available? 

5 minutes ago, Rclegg said:

What setting do you have it on during the day? 

When you say its constantly switching; do you mean that the mode is constantly switching (From SBU, to SOL, to grid) for example? or that you are simply using battery during the day? 

Could you provide a graph of your PV generation VS consumption if you have something like that available? 

Always set to SOL

When solar energy isn't available it is meant to switch to Utility completely. Which is does do, eventually. It's just that during that last hour or so of sunlight in the day where wattage drops to negligible it constantly tries to switch from PV to battery and then back to PV (SOL setting defines this, when Solar energy is not available switch to Grid)

 

Problem is it still sees that negligible wattage as solar energy being available (2w to 10w), when really all I want the system to do is have a threshold where if a wattage under say 50w is being generated, ignore that and just switch over to grid. 

 

I've yet to embark on monitoring software - that's next on the list.

Does anyone perhaps know if a DC Breaker with timer exists?

What I've been doing is flipping the PV breaker at 9am - starts PV generation - then flip it again as the sun starts to fade and the inverter shows low wattage - this stops PV and forces the inverter to go to grid. This has been working well for me but I'm thinking if a DC breaker with a timer exists - that would be a better option perhaps

I had the exact inverter. It was a nightmare to use.  And I hated the fact that I had to buy separate pieces and equipment to get more out of the unit.

 

I had a small PC on mine. Connected via a USB cable to the inverter. Inhad a solar monitoring software on the PC, and set schedules on the software as to when the inverter needs to do what.

 

From 09:00 I had setting 1 on SBU. Up untill 16:00. Then there after I had it on UTI only. It worked for me for the 5 months I used it.  I then got myself a new lithium battery and SunSynk inverter.  Never been happier 

2 hours ago, JoeyhZA said:

Does anyone perhaps know if a DC Breaker with timer exists?

What I've been doing is flipping the PV breaker at 9am - starts PV generation - then flip it again as the sun starts to fade and the inverter shows low wattage - this stops PV and forces the inverter to go to grid. This has been working well for me but I'm thinking if a DC breaker with a timer exists - that would be a better option perhaps

It's possible to do this via software instead. ICC being one of them. I believe they cover most Axpert inverters. 

57 minutes ago, Rclegg said:

It's possible to do this via software instead. ICC being one of them. I believe they cover most Axpert inverters. 

Thanks - looking to not shell out bucks on this problem

Is there perhaps a free software option that could accomplish something similar?

 

Thing is, I'm aiming to go with a Solis option as well. The current Axpert solution works perfectly for backup during loadshedding for essential loads. I slapped on some solar panels as an interim measure. Aim is to go grid tied with limiter and move the current panels as well as add a few more panels to the Solis in the near future.

That's a few months away though and was hoping for a quick and non-fuss solution to the problem. Well, a better solution that the manual flipping of breaker I currently adopt now

Edited August 17, 20214 yr by JoeyhZA
addition

33 minutes ago, JoeyhZA said:

Thanks - looking to not shell out bucks on this problem

Is there perhaps a free software option that could accomplish something similar?

 

Thing is, I'm aiming to go with a Solis option as well. The current Axpert solution works perfectly for backup during loadshedding for essential loads. I slapped on some solar panels as an interim measure. Aim is to go grid tied with limiter and move the current panels as well as add a few more panels to the Solis in the near future.

That's a few months away though and was hoping for a quick and non-fuss solution to the problem. Well, a better solution that the manual flipping of breaker I currently adopt now

Also went this way but now wondering how to ensure the batteries are charged from solar, especially if you plan on running lights etc off them at night.

On 2021/08/16 at 11:17 AM, JoeyhZA said:

Issue : Constant switching between Battery and PV and then eventually to Grid.

This is one of the biggest issues I also experienced with my inverter. I ended up fitting a sonoff switch that switched a relay on and off with timer settings. I switched off the grid supply instead of the PV. I forced the inverter to stay on battery mode until it was completely dark and only then switched to grid with the sonoff timer. This could also work for you but you need to know your batteries can handle the task. 

My system worked perfectly for more than two years like that but two months back I decided to install ICC and than stopped using the sonoff timer and thought I could rely on the ICC to control the modes but on Saterday with the cloudy weather in Johannesburg my inverter made the famous Axpert popping sound while it was switching between modes, so now the Sunsync is on its way. 

 

17 minutes ago, gooseberry said:

Also went this way but now wondering how to ensure the batteries are charged from solar, especially if you plan on running lights etc off them at night.

Well, with the grid tied option - I'm thinking the batteries on my current Axpert will still be charge from solar regardless (even with no panels connected to the Axpert)

The Axpert will be set to charge from Utility and for all intents and purpose the Axpert will see the power the grid tied Solis pushing in as Utility power anyway, and charge the batteries that way. Load dependent of course and my daily loads aren't exorbitant, so should be enough excess to charge batteries.

 

Thats my logic anyway - and I'm almost certain it will work that way

Edited August 17, 20214 yr by JoeyhZA

13 minutes ago, JoeyhZA said:

Well, with the grid tied option - I'm thinking the batteries on my current Axpert will still be charge from solar regardless (even with no panels connected to the Axpert)

The Axpert will be set to charge from Utility and for all intents and purpose the Axpert will see the power the grid tied Solis pushing in as Utility power anyway, and charge the batteries that way. Load dependent of course and my daily loads aren't exorbitant, so should be enough excess to charge batteries.

 

Thats my logic anyway - and I'm almost certain it will work that way

Will you put a timer on it? And you don't mind charging from utility when it's a bit cloudy or other loads are using the solar? Looking for a way to could set it up that it just sunk all extra solar energy to the battery charger instead of how it would dump it to the grid if there was no CT clamp.

2 minutes ago, gooseberry said:

Will you put a timer on it? And you don't mind charging from utility when it's a bit cloudy or other loads are using the solar? Looking for a way to could set it up that it just sunk all extra solar energy to the battery charger instead of how it would dump it to the grid if there was no CT clamp.

Not aiming to go off-grid just yet - main aim is to reduce the monthly electricity bill. Secondary but coupled to that, I guess is do my bit to save the damn environment  and hope it all catches on, gains a lot more momentum and the world can be a little bit cleaner for my little one someday.

I'm not against charging from grid on days when solar isn't reliable or being used elsewhere - those, on paper, should be few and far between. I know in reality it likely won't turn out that way, but remaining optimistic (within what the budget allows).

Will definitely be saving for complete energy independence though. As soon as supercapacitors start becoming ubiquitous and plummeting in price.

 

On 2021/08/16 at 7:17 PM, JoeyhZA said:

During sunset I get constant switching. Inverter shows tiny wattage coming from the PV (as low as 2w) and the inverter switches constantly to battery and then back to PV.

It sounds like you have a model with a separate solar charge controller, i.e. one with a 145 V max PV voltage. Sometimes those turn their relay on and off around sunset and possibly sunrise, as there is/isn't enough power to run the solar charge controller. So you hear a soft ticking, but you'd have to be very near the unit to even be aware of it.

This is not "switching", at least not in the sense of switching hundreds or thousands of watts of load from one power source to another. It's just connecting or disconnecting those one or two amps of solar charge current.

Switching to use grid power for loads is a separate issue, involving the back to grid (setting 12) and other settings.