For several years, my meager 400 watt solar system supplied a bit of power at my cabin. But, a long-term goal of mine was to design and build a much larger system capable of powering my 240VAC well pump. This would reduce fuel consumption on the homestead significantly.
Using a clamp meter I determined that the 1.5hp pump was using 10 amps to run. This Fluke meter also has "in-rush" capability, and measured that starting amperage at 37-38 amps (500 mSec). That means I needed a substantial inverter to supply that much power. I selected Schneider's XM6848 120/240VAC inverter that has up to 12kw of surge (5 seconds).
I coupled this to 15-300watt Renogy panels, wired three in series per array, a 3S5P configuration. The 115VDC from each array was funneled through a combiner box which feeds a Midnight 200 charge controller. The Midnight charges a bank of 8 L-16 batteries wired in series for 48V. I created ground arrays, made out of welded unistruts. Each array sits on a 3.5" pipe sunk 4' into concrete. A 4" pipe slips over the 3.5", with the frame attached. This allows the arrays to track both left to right, and can also be adjusted for seasonal position changes.
image_10177.jpg The frame fits over a single steel pipe sunk in 48" of concrete, which allows the array to track the sun left and right. The horizontal stabilizers at the bottom also allow for season angle changes. Here is the array with the panels installed.
image_10178.jpg
Though I did most of the wiring myself, my BIL is a retired electrician, so I had him inspect my work.
Last month we flipped the breaker to start the well pump, and the XM powered it up with ease. I'm now in the performance qualification phase of the system. My rule of thumb is to run the pump only while the panels are capable of making >2400 watts of power. This happens after about 9:30 in the morning. If the arrays are swung over to face SE, the batteries are mostly charged by then. By noon though, there's enough excess power to bring the batteries up to float. I position the arrays manually to track the sun when maximal power is needed. On days I'm not pumping I just lock the arrays facing south and forget about them.
Using a clamp meter I determined that the 1.5hp pump was using 10 amps to run. This Fluke meter also has "in-rush" capability, and measured that starting amperage at 37-38 amps (500 mSec). That means I needed a substantial inverter to supply that much power. I selected Schneider's XM6848 120/240VAC inverter that has up to 12kw of surge (5 seconds).
I coupled this to 15-300watt Renogy panels, wired three in series per array, a 3S5P configuration. The 115VDC from each array was funneled through a combiner box which feeds a Midnight 200 charge controller. The Midnight charges a bank of 8 L-16 batteries wired in series for 48V. I created ground arrays, made out of welded unistruts. Each array sits on a 3.5" pipe sunk 4' into concrete. A 4" pipe slips over the 3.5", with the frame attached. This allows the arrays to track both left to right, and can also be adjusted for seasonal position changes.
image_10177.jpg The frame fits over a single steel pipe sunk in 48" of concrete, which allows the array to track the sun left and right. The horizontal stabilizers at the bottom also allow for season angle changes. Here is the array with the panels installed.
image_10178.jpg
Though I did most of the wiring myself, my BIL is a retired electrician, so I had him inspect my work.
Last month we flipped the breaker to start the well pump, and the XM powered it up with ease. I'm now in the performance qualification phase of the system. My rule of thumb is to run the pump only while the panels are capable of making >2400 watts of power. This happens after about 9:30 in the morning. If the arrays are swung over to face SE, the batteries are mostly charged by then. By noon though, there's enough excess power to bring the batteries up to float. I position the arrays manually to track the sun when maximal power is needed. On days I'm not pumping I just lock the arrays facing south and forget about them.
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