Hi , thinking of getting this inverter for the farm , and 15kw of solar panels . Probably 5kw or 10kw battery for now.  Got a few questions 

can this inverter work off grid or does it need Eskom power?

do the loads have to be balanced on each phase , or will it just supply power to each phase as required , subject to max ?
 

is the max 20kw per phase or just a total draw of 60kw across the 3 phases ?

 

would it make sense to split the panels over as many mppt inputs as possible , or over as little as possible (all will be north facing at 25cdegrees )?

thanks for your help
 

 

Hi Gimpex,

The Sun2000 is. Grid tied inverter. It needs Eskom to work or at least an AC source of power to be fooled to work. AC coupling is a way to do this. 

But it's grid tied in design. 

Thanks Steve , thried to Google AC coupling but couldn’t see anything relevant. Is that a way of “fooling “ the inverter to thinking there is eskom when in fact there isn’t?
 

And if it needs eskom does it go down with load shedding or it just needs occasional eskom connection but can operate without eskom for some period of time ?

1 hour ago, Gimpex said:

Thanks Steve , thried to Google AC coupling but couldn’t see anything relevant. Is that a way of “fooling “ the inverter to thinking there is eskom when in fact there isn’t?
 

And if it needs eskom does it go down with load shedding or it just needs occasional eskom connection but can operate without eskom for some period of time ?

Grid tied needs a permanent Eskom voltage in order to synch its own output to the Eskom supply. If no Eskom by law they will always switch off. On bigger installations the grid input can be received from a generator when in island mode.

You might Google GRID TIED for details on how it operates.

Operation. Grid-tie inverters convert DC electrical power into AC power suitable for injecting into the electric utility company grid. The grid tie inverter (GTI) must match the phase of the grid and maintain the output voltage slightly higher than the grid voltage at any instant.

Thank you , read up more on this one and it’s not what I’m looking for unfortunately. Will look at the sunsynk 12kw 3 phase inverter.

Sent their support an email with a few questions , let’s see. 

6 hours ago, Gimpex said:

Thank you , read up more on this one and it’s not what I’m looking for unfortunately. Will look at the sunsynk 12kw 3 phase inverter.

Sent their support an email with a few questions , let’s see. 

OK. Perhaps you can bounce the questions here as well. We have a number of great installers that know their stuff and other technical guys that can assist.

2 hours ago, Scorp007 said:

OK. Perhaps you can bounce the questions here as well. We have a number of great installers that know their stuff and other technical guys that can assist.

Thank you. I have received the answers , so I paste the question and response below , in case others have comments , or just as a reference for others who might want to know

1. If I have 2 of these inverters in parallel , would I be able to connect up to 15kw of solar panels to each of these inverters ?- yes that is correct

2. If I have 2 of these inverters in parallel , would the effective maximum draw on each phase be 12kw ( 6kw x 2) ?- no, the total 24KW is split over 3 phases. 24Kw/3

3. Do I need to connect batteries to both , or can i have 2 x 4.8kwh batteries connected to just one inverter ?- No, it must be a common battery bank and batteries needs to handle 500A/48V max discharge current.

4. These inverters have input for generators , which do not often come in 3 phases. will I be able to connect a normal single phase diesel generator to one phase ? If yes , would only that phase get use of the generator or will the inverter then give a max of 50% of one phase power to another phase ?- NO, it must be a 3 phase generator of double the capacity of inverter system.

 

I have since googled and 3 -phase generators are not that uncommon actually. Seen a few in the 25kva range , they are from R35k upwards , so not cheap but definitely an option if Eskom is not. 

Also , any comment on point 2 - batteries , how would one connect them , and the draw seems very high. What sort of battery would be able to deliver that ? Am I correct in saying that I can connect normal Hubble / Pylontech batteries , if the draw wont be that high on batteries ? I plan to run all the heavy energy items like borehole pumps , geysers , machinery during the day when solar is feeding the system , and batteries are there for the night time , mainly lights , occasional pump from big tank to small tank , normal 220V plugs etc. 

 

 

 

1 hour ago, Gimpex said:

Thank you. I have received the answers , so I paste the question and response below , in case others have comments , or just as a reference for others who might want to know

1. If I have 2 of these inverters in parallel , would I be able to connect up to 15kw of solar panels to each of these inverters ?- yes that is correct

2. If I have 2 of these inverters in parallel , would the effective maximum draw on each phase be 12kw ( 6kw x 2) ?- no, the total 24KW is split over 3 phases. 24Kw/3

3. Do I need to connect batteries to both , or can i have 2 x 4.8kwh batteries connected to just one inverter ?- No, it must be a common battery bank and batteries needs to handle 500A/48V max discharge current.

4. These inverters have input for generators , which do not often come in 3 phases. will I be able to connect a normal single phase diesel generator to one phase ? If yes , would only that phase get use of the generator or will the inverter then give a max of 50% of one phase power to another phase ?- NO, it must be a 3 phase generator of double the capacity of inverter system.

 

I have since googled and 3 -phase generators are not that uncommon actually. Seen a few in the 25kva range , they are from R35k upwards , so not cheap but definitely an option if Eskom is not. 

Also , any comment on point 2 - batteries , how would one connect them , and the draw seems very high. What sort of battery would be able to deliver that ? Am I correct in saying that I can connect normal Hubble / Pylontech batteries , if the draw wont be that high on batteries ? I plan to run all the heavy energy items like borehole pumps , geysers , machinery during the day when solar is feeding the system , and batteries are there for the night time , mainly lights , occasional pump from big tank to small tank , normal 220V plugs etc. 

 

 

 

If you have a 8kw inverter say per phase. This means at 48V you need a battery that can provide 166A. For 3 phase and 3 inverters you need 166x3=500A.

This is very normal for any inverter.

One more please. If i have 2 x Sunsynk 12kw 3phase inverters connected in parallel, and one of them packs up, will the other one still supply power? 

The way i see it, 2 x 3phase inverters cost R120k and gives me at least 8k per phase. If i get 3x 8kw single phase inverters, for a 3 phase installation, it will cost around R100k, but if one dies, one phase will lose all power so better to go for the first sxenario?