Wire Gauge Required Question
For some reason I just can't understand the various wire gauge tables, and I have tried to, so I am hoping somebody will take pity and do all the work! :) One table that I can follow says that for...
Forum Discussion
Hi Bend,
The "magic" of MPPT is the ability to swap incoming volts for outgoing amps. Therefore, on MPPT systems voltage drop matters.
On an 17 volt pwm system voltage drop can be horrendous, and the system may still work well. A 14.8 volt target allows for ~14% voltage drop. So on pwm thin wire doesn't matter much. So long as the wire has sufficient ampacity to safely carry the load it will be adequate.
But for MPPT it is best to aim at 1% voltage drop, because once those volts "hit" the controller they are turned into amps (with a 3 to 6% loss inside the controller, depending on input voltage).
It is true that higher voltage allows for smaller wire--but line losses DO matter for MPPT.
Controller to battery for MPPT, may need to be beefed up compared to PWM because more amps may be output to the battery bank for a similar wattage of panels.
The "magic" of MPPT is the ability to swap incoming volts for outgoing amps. Therefore, on MPPT systems voltage drop matters.
On an 17 volt pwm system voltage drop can be horrendous, and the system may still work well. A 14.8 volt target allows for ~14% voltage drop. So on pwm thin wire doesn't matter much. So long as the wire has sufficient ampacity to safely carry the load it will be adequate.
But for MPPT it is best to aim at 1% voltage drop, because once those volts "hit" the controller they are turned into amps (with a 3 to 6% loss inside the controller, depending on input voltage).
It is true that higher voltage allows for smaller wire--but line losses DO matter for MPPT.
Controller to battery for MPPT, may need to be beefed up compared to PWM because more amps may be output to the battery bank for a similar wattage of panels.
Bend wrote:
PT-
You are going to need to explain why. I thought part of the "magic" with MPPT was that smaller gauge wire could be used. At least, from panels to controller due to higher voltages. Controller to batts would remain the same as PWM.
