Solar wiring question
Currently I have 2 100 watt panels on top of the trailer (VOC 21.6 volts, ISC 6.34 amps, VPM 17.4 volts, IMP 5.75 amps) with a 30 foot run of 12ga wire to the charge controller. Last fall my system...
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I use a Solar30 PWM with my three 100s in parallel. The Windy Nations P30L is the same. Good controller for the job. You must wire the 100s in parallel with the PWM.
If the two 100s worked for you, a third might not be necessary but could be better.
AFAIK there are some different sizes of MC4 and singles vs double. Also the panels might have junction boxes you can connect wire to or else pigtails with MC4. I can get #8 in the panel junction boxes so then I just need a combiner box up there and a single pair of #8 down to the controller.
If the panels have pigtails, likely they are aluminum #12 with MC4 so you need to wire from the pigtails to the combiner box too. One way is to cut the pigtails short, and join the pigtail al #12 to your copper #8 (however you like--but need to tape it up to keep it dry) and then go with #8s to the combiner.
If the pigtails are long enough to reach the combiner then it is easier--if you are that lucky!
I am suspicious, based on the pigtails, that when you buy say 25 ft of wire with MC4s it might be aluminum wire, which acts like a higher number gauge from copper even though they call it #12. That can matter for calculating line loss.
If the two 100s worked for you, a third might not be necessary but could be better.
AFAIK there are some different sizes of MC4 and singles vs double. Also the panels might have junction boxes you can connect wire to or else pigtails with MC4. I can get #8 in the panel junction boxes so then I just need a combiner box up there and a single pair of #8 down to the controller.
If the panels have pigtails, likely they are aluminum #12 with MC4 so you need to wire from the pigtails to the combiner box too. One way is to cut the pigtails short, and join the pigtail al #12 to your copper #8 (however you like--but need to tape it up to keep it dry) and then go with #8s to the combiner.
If the pigtails are long enough to reach the combiner then it is easier--if you are that lucky!
I am suspicious, based on the pigtails, that when you buy say 25 ft of wire with MC4s it might be aluminum wire, which acts like a higher number gauge from copper even though they call it #12. That can matter for calculating line loss.
