PWM input voltage, Xantrex C40 test video
here is the Video link, the fluke is plugged directly into the Solar panel drop wiring before it enters the controller right above the panel input protection fuse, that i use for a disconnect just c...
Forum Discussion
What is the R across that fuse (used as a switch) between where the 17v was seen and the actual panel terminals on the controller? Would that do it? (or did I get that wrong where the fuse is?)
People keep saying you can't get Isc with the panel hooked up, but that is just semantics. The I on the IV curve is at the Isc amount of amps on the left and then stays close to that amount until battery voltage (the V in the IV) goes up some. So when people say you "get Isc at the battery with PWM" that is just short for, "You get the same amount of amps at the battery as the amount of amps you would get at that moment at the panel with the panel disconnected" (the Isc of the moment can be anything up to the panel's rated Isc and even higher than that at times.)
That means if the panels are in "full sun" (as with STC) you should get the total rated Isc of the several panels in parallel to the controller input and to the battery. Mostly you get less than that unless the panels are aimed at the sun on a sunny day.
The C40 manual says it is a series type PWM controller, nothing special indicated compared with the rest of the series type PWMs that have panel voltage at battery voltage plus line loss. So what is Mr Wiz saying is in fact different with the C40?
Why was there a diode to prevent night loss when the controller has that automatic night time shut off feature? Does that mean the dumpers are installed so it did need that diode (per manual)? Would it be a good idea to uninstall the dumpers since the controller is only being used to control PVs?
People keep saying you can't get Isc with the panel hooked up, but that is just semantics. The I on the IV curve is at the Isc amount of amps on the left and then stays close to that amount until battery voltage (the V in the IV) goes up some. So when people say you "get Isc at the battery with PWM" that is just short for, "You get the same amount of amps at the battery as the amount of amps you would get at that moment at the panel with the panel disconnected" (the Isc of the moment can be anything up to the panel's rated Isc and even higher than that at times.)
That means if the panels are in "full sun" (as with STC) you should get the total rated Isc of the several panels in parallel to the controller input and to the battery. Mostly you get less than that unless the panels are aimed at the sun on a sunny day.
The C40 manual says it is a series type PWM controller, nothing special indicated compared with the rest of the series type PWMs that have panel voltage at battery voltage plus line loss. So what is Mr Wiz saying is in fact different with the C40?
Why was there a diode to prevent night loss when the controller has that automatic night time shut off feature? Does that mean the dumpers are installed so it did need that diode (per manual)? Would it be a good idea to uninstall the dumpers since the controller is only being used to control PVs?
