So as THD increases power use decreases?


On Thu, 21 Oct 2004 10:20:17 -0300, Derek Broughton
wrote:

bluegill phil wrote:

You should add more valves on the outlet to divide the flow . Let the
pump push only as much as it takes to reach the top of your falls by
diverting pressure somewhere else. You may pump more water but for
less wasted pump life and power

If I understand you correctly, you're suggesting that you should run the
pump at full flow to save energy. This isn't actually the way these pumps
work. If you restrict the output they use _less_ energy than if you run
them wide open. Less wasted pump life and power. It seems
counterintuitive, but it's true.

bluegill phil wrote:

So as THD increases power use decreases?


On Thu, 21 Oct 2004 10:20:17 -0300, Derek Broughton
wrote:

bluegill phil wrote:

You should add more valves on the outlet to divide the flow . Let the
pump push only as much as it takes to reach the top of your falls by
diverting pressure somewhere else. You may pump more water but for
less wasted pump life and power

If I understand you correctly, you're suggesting that you should run the
pump at full flow to save energy. This isn't actually the way these pumps
work. If you restrict the output they use _less_ energy than if you run
them wide open. Less wasted pump life and power. It seems
counterintuitive, but it's true.

THD? TDH? Total Head, anyway. Yes. To the point that it should use the
least power when you have sufficient head to get no flow.

I tried to find some of the old discussions on this topic. About the best I
could come up with is a thread:

http://groups.google.com/groups?q=po...aol.com&rnum=1

If you have trouble with that link, google for 'pond pump power consumption
head "power factor"'. Read anything by Rod Fairlee.

Whatever happened to Rod, anyway? He seems to have stopped posting about
the same time I did.
--
derek

yep... right you are derek, on all counts. Jan out in SE Washington state
knows where he
is ... sorry I don't
Nedra

"Derek Broughton" wrote in message
...
bluegill phil wrote:

So as THD increases power use decreases?


On Thu, 21 Oct 2004 10:20:17 -0300, Derek Broughton
wrote:

bluegill phil wrote:

You should add more valves on the outlet to divide the flow . Let the
pump push only as much as it takes to reach the top of your falls by
diverting pressure somewhere else. You may pump more water but for
less wasted pump life and power

If I understand you correctly, you're suggesting that you should run the
pump at full flow to save energy. This isn't actually the way these
pumps
work. If you restrict the output they use _less_ energy than if you run
them wide open. Less wasted pump life and power. It seems
counterintuitive, but it's true.

THD? TDH? Total Head, anyway. Yes. To the point that it should use the
least power when you have sufficient head to get no flow.

I tried to find some of the old discussions on this topic. About the best
I
could come up with is a thread:


http://groups.google.com/groups?q=po...ad+%22power +
factor%22&hl=en&lr=&ie=UTF-8&selm=20010721125459.01949.00000791%40nso-fu.aol
..com&rnum=1

If you have trouble with that link, google for 'pond pump power
consumption
head "power factor"'. Read anything by Rod Fairlee.

Whatever happened to Rod, anyway? He seems to have stopped posting about
the same time I did.
--
derek