Hi  I have a 3kva/3kw Axpert VM hybrid       inverter ("Solar Solved Africa"   brand)  and two  230ah flooded lead acid batteries. The inverter is set to prioritise our two 275w solar panels.             
At irregular intervals the inverter   display  "freezes" and there is no power output.      
   On advice from the installer who sold it to me I solve this by :-      

*Switching off utility power
*Disconnecting the solar panels   
*switching off the inverter  
 *   I then disconnect power from the batteries, wait a couple of minutes then reconnect.
*then switch on the inverter, utility and solar power.

It always happens when there is little or no input from the solar panels. 
 My inverter firmware versions are
U1 06 23

U2 01 12    
 Has anyone found a way to permanently prevent this behaviour?

2 hours ago, Zimbo said:

At irregular intervals the inverter   display  "freezes" and there is no power output.      
   On advice from the installer who sold it to me I solve this by :-      

That should not be happening, and you should not have to do this procedure. It seems like the DSP inside the inverter is crashing. That seems like it has to be the internal power supply, that converts 24 V from the battery to 5 V, ±12 V, etc; I assume that the DSP itself runs off 5 V (or more likely 3.3 V and 1.8 V, all stepped down from 5 V or 12 V). Unless there is something flaky about your battery or its cables/fuses/lugs etc, it pretty much has to be an inverter fault. Can you check the voltage at the inverter battery terminals with a multimeter next time this happens?

Edit:

2 hours ago, Zimbo said:

My inverter firmware versions are
U1 06 23

U2 01 12    

For once, I'm not familiar with those version numbers. I mainly study the 5 kVA models.

Edited July 9, 20206 yr by Coulomb

Thanks Coulomb.

I will check voltages when it happens again

I woke up this morning to discover that our inverter had "frozen" again.

The battery voltages were 13.70v and 13.18v before I did anything. Immediately after "rebooting" the inverter they were 12.85v and 12.81v respectively. A few moments later the inverter read 25.4v.

(The initial imbalance may be because one battery is a few months older than they other).

 

5 hours ago, Zimbo said:

The battery voltages were 13.70v and 13.18v before I did anything. Immediately after "rebooting" the inverter they were 12.85v and 12.81v respectively.

The imbalance is not good; you should try to charge the lower voltage one with a car battery charger until they read closer to the same after resting (or just very low loads) for several hours. It's a tedious and time consuming task, but it could save you wearing one out prematurely, and give you longer run time as well.

But those voltages look healthy; I just wanted to rule out that the battery voltage was collapsing under load. So it's looking like an inverter fault causing the freezes.

Thanks Coulomb

Thanks for your ideas regarding voltage balancing.

I have a voltage balancer connected but will monitor it more carefully over time.

Out of interest I changed my inverter setting from UPS to APL (for appliance) and it no longer freezes