I think the ES model is the later one, and that the differences are on the first page of the full PDF datasheets at the bottom of each inverter page. For example, with the ES it is possible to scheduler charging and discharging time slots-could be very useful
Hi, I have been looking at these inverters as well, and what has made me decide for the ES series is that you can run it without having any batteries if you want to.
I have the 5000ES model and have had in in use for a couple months now. Although they claim it will work without batteries, the performance would be horrible. The problem is the sun intensity varies minute to minute as clouds pass, one minute the inverter can be outputting 4KW and seconds later only 500-600 watts. Without a battery bank of some sort there is nothing to "fill in" during those short periods of low output and depending on your loads, the inverter would fault out. I have 340ah of 48V battery bank and it works very well. It would be pretty useless without a battery bank of some sort, even a real small one.
I understand, - but this is not the inverters fault. So, yours is running perfectly huh? How is the noise?
Thank you for sharing your experience so far.
Its loud when the fans spool up. Mine is in a shop room in my pole barn, not in the house so noise isn't something that matters to me. Its a lot of power in a small package so cooling is important.
I read in the manual that we can set up sub priority (Program 01), by doing so shouldn't the utility grid "fill in" during periods when solar energy isn't enough to power the loads?
)Thank you for you reply.
Hi again,
www.mayfield.energy
program 49 (user manual) says Utility Charging time slot.I think the ES model is the later one, and that the differences are on the first page of the full PDF datasheets at the bottom of each inverter page. For example, with the ES it is possible to scheduler charging and discharging time slots-could be very useful
Thank you so much for your extensive reply.Not sure if you already built your system @Julian-Indaiatuba.
Advice valid for anyone else.
Pay attention to the total Voc of the string panel.
In the worse conditions (summer, high temperatures) you need to have the lowest Voc > low limit voltage of the MPPT (the smallest number of PV in series)
In the best conditions (winter, low temperatures) you need to have the highest VoC < high limit of the MPPT (the max number of PV in series)
There are calculations for these voltages and there are websites which assists you in this calculus
https://solardesignguide.com/calculating-string-size/
How to Calculate PV String Size — Mayfield Renewables
How to manually calculate PV string size for photovoltaic systems based on module, inverter, and site data. Design code-compliant PV systems and follow design best practices.
Aproximative calculus for Voc, don't believe what I say, do your calculations:
your panel 37,8V 25degC
at 59degC --- ~31V
at -15degC --- ~41,7V
so a string of 10p will be ~417V quite close to the upper limit.
It is true the higher voltage brings lower current and thinner wires BUT,
DC/DC conversion efficiency gets lower together with voltage difference increase between input and output of the DC converter (MPPT in this case).
400V -> 56V (max battery voltage) efficiency is lower than 240V -> 56V and more power will be dissipated on the first one.
You can still make some adjustments because you have 4500W PV power available on the SPF3500 datasheet. The Current will be no problem since it admits 80A and 2 strings will provide 20A.
4500W/335W = 13 panels total
you can do 6s2p and have: 4kwp, max 250V per string, possibility to buy half panel now and do upgrade later when other money comes.
program 49 (user manual) says Utility Charging time slot.
program 14 sets charger priority (CGPr CSO/SNU/OSO)
program 21 give info that when battery is v.low, it will be charged from utility (matter not really clear)
