Mastervolt 2000XS for trade.

tok · Mar 16, 2012

I have just installed a new PV system on my house with a company to help them get their MCS.
It is only 5 panels REC 240V(no room for more). Unfortunately I let the company order the whole system from a stockist that recommended a Mastervolt 2000XS(probably because they had nothing lower powered at the time, and there seems to be a national shortage of SB1200's atm)
I tried to source a smaller inverter, considered stacking a couple of stella grid 600w inverters. etc
Then a so called expert ran the Fronius IG15, Mastervolt 2000XS and SB1200 through PvSol and said the Mastervolt came up trumps and would probably last longer anyway.
So to save time and help this company I went with it...
Now the Mastervolt 2000XS seems to be under-performing with a typical solar irradiance of say ~ 500W/m^2 (south facing, pitch 30 deg, no shading) and I was wondering if anyone wants to swap me a SB1200(or equivalent, hopefully new) for a few days old Mastervolt 2000XS?
In surrey area.

screwdriver · Mar 16, 2012

How are you quanitifying the underperformance, it isn't really the best time of year to see what systems produce, that inverter is running at the bottom end of its capacity but it really shouldn't be that bad as it is within the voltage limits of the inverter and very close to the mpp depending on the temperature.

tok · Mar 17, 2012

screwdriver said:
How are you quanitifying the underperformance, it isn't really the best time of year to see what systems produce, that inverter is running at the bottom end of its capacity but it really shouldn't be that bad as it is within the voltage limits of the inverter and very close to the mpp depending on the temperature.

i measured the output of the panels as about 5 amps Isc and 170Voc(at about 500W/m^2), but the inverter was only recording 2.5A and 135V on the DC side.
2.5 x 135 = 338 watts, which i thought should be more like 500-600 watts at that sort of irradiance with a better matched inverter?

i am in the process of connecting an ethernet cable to the mastervolt to monitor it more closely.

babba · Mar 17, 2012

I will swap you a caravan...

Glen Powell · Mar 18, 2012

Look at the tec spec again, the voltage range should be there however the Wp range is not, according to tec spec it has to be above 1300wp to be at best, the fact is this inverter has no DC boosters so cannot work at low voltages as efficiently, I would recommend power one or steca for this type of array.

tok · Mar 18, 2012

Glen Powell said:
Look at the tec spec again, the voltage range should be there however the Wp range is not, according to tec spec it has to be above 1300wp to be at best, the fact is this inverter has no DC boosters so cannot work at low voltages as efficiently, I would recommend power one or steca for this type of array.

Yes the tech spec is rather confusing for the Mastervolt, as it says max input power 1670W.
Power range 1300-2000Wp (not sure what the p means!)

Glen Powell · Mar 18, 2012

the p stands for peak

Glen Powell · Mar 18, 2012

If you got good voltage but low irradiance then the ampage will be down in turn I am sure the wattage will be considerably less, this will explain the poor performance.