eco worhty hybrid inverter panel setup

[bugsb]

just replaced my old hybrid inverter (2000w) with an eco 24v 3000w , now it said on the tin max 1500w input i have laying on a flat roof x2 400w panels and x2 245w panels , i would like to replace the x 245w with another x2 400w panels , guessing as the panels are flat they will never reach there full output to over load the inverter,
any thoughts on this or anyone have a larger setuo on an eco-worthy inverter

 

[MichaelK]

Does the MPPT on this unit have one input or two? You need to match parallel voltage strings within ~5% for the system to work properly.

To give you an good answer we really need to know the specifications of the equipment you are working with. Is it this one?

This unit appears to have only one MPPT input, and that has a max voltage of only 100V. That means the Voc of your panel string at the lowest winter temperature you are ever likely to see needs to stay below 100V. This is coastal Australia? Does the winter weather drop to freezing? Will you be camping in the mountains where the temp drops below freezing? I think only two panels would be safe below freezing, but we really need the panel specifications to make an informed decision.

Most likely, if laying flat on the roof, your amperage output would not likely surpass 75% of panels oriented directly at the sun. Assuming you have 1600W total, and battery charging starts at ~25V, the math looks like this: (1600W/25Vcharging) X 75% = 48A. So, your MPPT is likely to handle the amperage just fine. DO NOT wire all four panels in series. The voltage would be high enough to fry the controller. Wire them 2S2P, but pay close attention to with the cold-weather Voc is.

 

[bugsb]

i think the unit is a copy its white , but i tested it today for a while at around 2700w (kettle) it worked well .
rated power 3000w
peak 6000w debaitable
dc input 24v
rated currant 60A
rated power 1500w
mppt tracking range 30-115v
operating volt range 30- 145v
max solar voltage 150v

panels 400w
NOCT Voltage at Maximum Power Vmp/V30.15

NOCT Open Circuit Voltage Voc/V36.93
NOCT Current at Maximum Power Imp/A10.78
NOCT Maximum power Pmax/W325
STC Voltage at Maximum Power Vmp/V33.04
STC Open Circuit Voltage Voc/V39.33
STC Current at Maximum Power Imp/A13.17
temp around this area of the uk -5c to 39degc

 

[MichaelK]

OK, I plugged your data into Midnight Solar's string calculator

MidNite Solar - Classic Sizing Tool.

MidNite Solar is the industry leader and manufacture of quality Renewable Energy System electrical components and E-Panels.

www.midnitesolar.com

It looks like you might perhaps get away with a single string of three panels, which at -5C is going to put out ~130V. If your unit can indeed go up to 145Voc, you might be safe. Still, four panels in a 2S2P configuration looks better than 3S1P. One thing to think about is if your unit is actually a cloned knock-off, I'd approach that 145Voc value very carefully. The companies putting out the in-expensive copy-cats, cut corners with every single component.

 

[bugsb]

thanks i will keep it safe and go for the 2s2p setup