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
red31 wrote:
"PWM or 16.62-13.92 * 16.10a = 43.47 Watts going to heat up controller?
"16.62
controller out
13.92v"
Think about 43.47 Watts going to heat up controller. If you have a series PWM controller and it is in the off state the panel voltage is at V open circuit as you have said. But in the off state the current is zero! With zero current there is no power dissipation (P = V*I) to heat the controller.
Also if you have a shunt type PWM controller and if is in the off state the panel voltage is zero, the panel output is shorted by the controller. With zero voltage there is no power dissipation (P=V*I) to heat the controller. OK there will be a small voltage drop across the shunt switch so there will be a small amount of power dissipation with a shunt controller.
"PWM or 16.62-13.92 * 16.10a = 43.47 Watts going to heat up controller?
"16.62
controller out
13.92v"
Think about 43.47 Watts going to heat up controller. If you have a series PWM controller and it is in the off state the panel voltage is at V open circuit as you have said. But in the off state the current is zero! With zero current there is no power dissipation (P = V*I) to heat the controller.
Also if you have a shunt type PWM controller and if is in the off state the panel voltage is zero, the panel output is shorted by the controller. With zero voltage there is no power dissipation (P=V*I) to heat the controller. OK there will be a small voltage drop across the shunt switch so there will be a small amount of power dissipation with a shunt controller.
