Jack wrote:
Astro wrote:
I purchased a quiet two speed pump, Pentair Whisper-flow

do you now run it only on 2nd low speed and do you have to hit a manual switch or can
it be programmed to select 1 or 2?

what's the amp/watts at low speed?

On slow speed, it's adding 300w to my home base load. I didn't take the
time to meter it for amps, power factor or anything else. On high
speed, it's 1600w. Wattage measurements made with a TED device, which
very closely matches my home electric meter readings.

As noted, the piping on my pool is undersized so the head pressure is
quite high. That would help the low speed condition even more as the
turbulence should be much lower on low setting.

I run it low speed 12h/day. The only time I switch to high now is to
backwash and it's keeping my 28000gallon pool crystal clear. Much
better than when I ran the original pump full out for 6 hours/day.
The manufacturer rates it as: 7.8A/3.0A (230v) at full load. so VA
would be 1800w/690w so this it telling me based on the specs that my
suspicion is pretty much correct - the pump is nearly fully loaded at
high speed and has a low load at low speed. I'm figuring that my old
pump was using something like 2kw * 4 = 8kwh vs. the new one at .3kw *
12 = 4kwh per day. It may have been worse. Based on the flow curves,
I'm guessing that I'm getting something like 20gpm at slow speed and
50gpm at high. So for .19x the watts, I get .4x the flow.

To be conservative, I'm saving about $0.60/day using the new pump
longer and getting significantly better filtration. Will it pay off?
That comes out to be something like a 9 year simple payoff, so it's not
huge. But I haven't experimented yet to see the minimum number of hours
I can run and get adequate filtration.

As for the two speed switch - it just has a toggle on the back.
However, you could wire it up to use a relay/timer to switch between
modes.