I have this inverter.
I can answer all your questions. I have been running this inverter batteryless without grid and with grid.
First let me tell you I am very happy so far with it .
Yes when you have Grid mixed with AC grid , it shows false readings of feeding the grid. But a bidirectional smart energy meter shows otherwise . 0.00000kwhr. So the inverter is never backfeeding. Although the monitor program says it does.
I agree with what other people say about voltage.
I have 340V DC VOC from the panels , and they are suffering under load when its REALLY cloudy. Basically , the MPPT will go down to 120V under load, since this is the minimum operating voltage , to try to extract maximum power ( ampers ) but this is a "bad" zone. More voltage = better. I am not sure how exactly the MPPT works to favor the direct DC to AC but what I know is that it works really good when its sunny , not so good when its VERY cloudy. When its normal cloudy its fine with my 340V VOC.
I mean it works really good.
Also dont listen to people that say it doesnt work batteryless or it's not supposed to work like that.
I have tested it batteryless without AC and if your loads are fine under the cloudiest time, the inverter will work fine and as intended.
So example : Put 300w loads , with 3.1kw of solar panels flat on the ground , they switch on in the morning , run for the whole day fine and switch off when it gets dark. IT WORKS FANTASTIC AND AS INTENDED . I know though you will be wasting a lot of power this way but there are special applications where this makes sense. Worst case scenario is the inverter will cycle on/off.
Obviously if you are powering a home , you would need batteries to even the cloudy times and not lose energy but trying to have always the load at the minimum power production of the day ( like 300w from 3.1kw flat panels in November ) . The whole point is that you can mix with AC and avoid batteries.
I don't use batteries and it works FINE and as intended.
It's great.
The only problem is the N/G bond when you lose the AC in , which is solved with the dry contacts' external grounding box.
As people said , I would recommend at least 340V VOC like me , even more if you live in a very cloudy place . I would try to hit the 450V ideally. As I said when its really cloudy , the MPPT is kind of struggling.
Let me know if you have any questions .
Cheers.
