Finally deciding to add additional PV panels to my Axpert Inverter, led to the specification that my 3kVa Inverter has a maximum PV input of 600W. I already have two 300W panels, but on a not so clear day, I'm only sucking in around 350W. Can anyone tell me if exceeding the PV input will do any damage ? ....and is anything more than 600W going to be any worth at all ? Would the system accept anything above the rating anyway ? Yes, with the way things are going, maybe investing in later technology, bigger systems would be the proper answer - but let's see what I can can squeeze for now !

9 minutes ago, Pat de Klerk said:

Finally deciding to add additional PV panels to my Axpert Inverter, led to the specification that my 3kVa Inverter has a maximum PV input of 600W. I already have two 300W panels, but on a not so clear day, I'm only sucking in around 350W. Can anyone tell me if exceeding the PV input will do any damage ? ....and is anything more than 600W going to be any worth at all ? Would the system accept anything above the rating anyway ? Yes, with the way things are going, maybe investing in later technology, bigger systems would be the proper answer - but let's see what I can can squeeze for now !

You can get an external MPPT like the Epever in 20/30/40A and connect panels to this MPPT. The 20A will give you another 500W of PV power. 

Risky to just add more panels to the 600W that only produce 350W. What if you add another 300W and for some reason the 3 produce 900W and fry your inverter MPPT knowing that the spec indicates 600W maximum? 

Further you can add more than 1 Epever with own panels if you load the very same settings on each. 

What batteries do you use? 

Edited May 29, 20233 yr by Scorp007

Hi Scorp, Thanks. Currently still using lead acid (4 x 100Ah = 24V @ 200Ah). 

1 hour ago, Pat de Klerk said:

Hi Scorp, Thanks. Currently still using lead acid (4 x 100Ah = 24V @ 200Ah). 

So you don't really need a lithium profile when you look for a MPPT but if you want to future proof try to get one with lithium like the one mentioned. 

Edited May 29, 20233 yr by Scorp007

You can exceed the rated PV power of an Axpert inverter, and in theory it just takes what it needs. But the control of PV current becomes twitchy when you do this. The risk is not only to the internal solar charger, but to your battery as well.

I recommend a maximum of 20% more PV power than rated. 900W would here be 50%, so I certainly would not recommend it. 

Thanks guys....I have my answer then. Stick with what I've got in terms of PV......or worst case, invest in a completely new, higher rated system, if the stuff really hits the fan in SA !!!

10 hours ago, Coulomb said:

I recommend a maximum of 20% more PV power than rated. 900W would here be 50%, so I certainly would not recommend it. 

Even going up to 100% has some risks. My Axpert MKS 5K can handle up to 4kW PV input. I have 3kW rated panels connected to it. But I recorded peak inputs up to 3.8kW from the panels. That happens on partly cloudy days in summer when the sun suddenly hits the cold panels. It lasts only for short time until the panels heat up. But I wonder if the MPPT would stand it, if I had 4kW rated panels installed. 

21 hours ago, Pat de Klerk said:

bigger systems would be the proper answer

You could upgrade to a Axpert/Synerji MKS 4K with 4kW capacity. It can handle PV input up to 4kW at 60V to 115V.

Edited May 30, 20233 yr by Beat