MPPT Voltage limit is NEVER EXCEED, and you must allow for cold temperatures. Cold temperatures make panel Voc higher, so you will exceed 150V @ 15°C and lower.
MPPT Voltage limit is NEVER EXCEED, and you must allow for cold temperatures. Cold temperatures make panel Voc higher, so you will exceed 150V @ 15°C and lower.
The below diagram shows a 2s3p & 3p2s solar configuration respectively(at least I think that's what the configurations are called). I wired my 6 solar panels using the bottom example(3p2s) but afterwards I realized that I could wire them in a 2s3p configuration(top example). Are these...
Need math help. I have five, 440 watt panels with a 49.7 VOC each and I’m trying to string all 5 together and keep the VOC below 150 which is the max of my charge controller. Will wiring them 2s3p accomplish that?
You need the actual panel specs. If at maximum illumination power, the panels are Vmp of 48.0v x 10.23a Imp, their Voc will be about 56.5 vdc. If that spec is correct, it may be referenced at 40 degs C temperature or 25 degs C temperature depending on manufacturer spec sheet.
This reference temperature effects the temperature delta to your particular location coldest temperature you need to consider when applying the panel's voltage delta per degC temperature coefficient spec (typically about -0.3% to -0.4% per °C).
You need to stay within 150v controller limit at cold temp Voc. Morning time in cold weather is usually worse case situation since temp is coldest and there has not been much sun illumination time to warm up panels.'
Many SCC's will not start up on a cold morning if the input Voc gets too high. This is to help protect the unit from overvoltage. The MOSFET breakdown voltage of their DC-to-DC converter is greater when they are not switching so checking Voc before it starts up in the morning provides some extra protection against overvoltage input. Some SCC's have disconnect relays to panels which provides even better protection than just the MOSFET switching.
When a charge controller does an MPPT search the panel voltage can approach unloaded Voc voltage.