I've got a weird situation. My neighborhood has a long narrow water feature, about 250 feet long. Starts with a waterfall on one end, and water runs through a couple of pools and rock beds to a larger pool at the end of the feature.
It used to be powered by an external pump. I found the old pump house in some bushes near the large pool at the end, but the box is now empty except for some electrical. It appears that at some point the external pump was replaced by a submerged pump. Fortunately, the data sheet on the submerged pump was sitting in the pump house.
It is a CentriPro Model 6M071, single phase pump, 7.5 HP and consumes 36 amps at 230 volts! That's 8.28 kWh. In other words, this pump is a massive energy hog. We run it 24 hours per day and it's costing us about $700 per month to run.
Based on very limited research, it looks like we could get an external pump with comparable HP that runs on less than half the juice.
My question is, do we really need a 7.5 HP pump? I'm not sure how many GPM we need. The waterfall is a cascade maybe 8 feet wide, so it's a fair amount of water, but it's mainly being pumped horizontally. Probably 250-300 feet horizontal, and maybe only 6 feet vertical.
Does 7.5 HP sound right?
