Long wire run from panels to Suncentric DC water pump.

[Ojitopaul8]

The plan is to put two 550 watt panels ( 49.95 voc each, 14.05 short circuit amps each) in series to run a solar direct 24 volt Suncentric water pump ( it draws a maximum of 26.8 amps ) that's 90 feet away from the panels without needing a huge wire size and using a Victron 100 volt/30 amp 24 volt nominal output controller at the pump to bring the voltage down and the amperage up to what the pump needs. Maybe I'd need a larger controller as that would be 99.9 volts going into it. Even in series I think I'd need 180 feet of #4 wire. Any suggestions?

 

[OzSolar]

II'm not quite following your plan but that only means I'm just asking, not questioning.

The typcial solar pump controller doesn't use a 2nd controller between it and the panels.

panels>controller>pump. If your controller can take the 100 VOC you could use #10 copper.

Series would result in ~100Voc and 14.05 Isc.

 

[DIYrich]

Check the max voltage allowed by the Victron, and max voltage of panels at coldest temp. You can also factor in voltage loss over long wire. Thinner wire will increase voltage loss, which may be to your benefit to reduce the voltage into the range allowed by the Victron.

 

[hwy17]

What is the minimum voltage of the charge controller?

14 awg wire will drop 5% at 100 ft and 100v/10a. So 95v at the end of the line.

I don't think anything close to 4awg is necessary.

The other concern is if your cold voltage will rise above 100v, which it can. It doesn't seem like that charge controller is rated to handle that and you should use a 150v CC with those panels in series.

Also I don't know if you need a battery involved to make this work, but I would guess yes.

Do you already have the pump? A high voltage DC pump would seem much more optimal for this use case.

 

[Ojitopaul8]

Hyw 17.
Thanks for the advice.