Hi,
I have a quick question about looking at a temporary solution for a customer. The customer has ordered MPPT RS Chargers, and we are using 6x 455W Panels per String. We have designed a custom solar structure that uses 6x Solar Panels. Currently, there are no MPPT RS Chargers available.
Until the stock is available, I am thinking of buying maybe 3 or 4 MPPT 250-100 Chargers as a temporary solution to get the customer up and running. Obviously, the voltage of 6 panels in series is too high for the 250-100. The Panel VoC is 49.85.
My question is around using 5 Panels in series. The MPPT Calculator shows that at low temperatures, the VoC just exceeds 250 volts (around 260 volts), but at 24 C, we are well within the voltage limits and at full sun the voltage drops down to 172 volts.
When the voltage is fractionally over 250 volts, will the MPPT just give an error and wait for the voltage to drop before coming online, or are we talking about blowing the MPPT Charger at 260 volts?
Is there something I could do temporarily to induce a small voltage drop, as this is a temporary solution? Install an inline resistor maybe? Or multiple contactors driven by a voltage monitor / temperature monitor that only closes the circuit once the voltage is under 250 volts?
If I have 4x 250-100 Chargers, the difference between connecting 4 Panels or 5 Panels in series is nearly 4 kW, which is a significant boost for this temporary solution. If I can use 5 panels instead of a very safe 4 Panels connected in Series, it would be a much better working solution until the RS Chargers are in stock.
Looking forward to any thoughts and feedback. Thank you.
