Pond pump speed control (Andy)
 

3000LPH pump = 49L
1500LPH pump = 49L

Using real numbers from Via Aqua pumps
3000 lph = 45 watts
1500 lph = 15 watts
30 watts x 24 hours = 720 watts perday
365 days x 720watts = 262800
262.8 kwatts x .5L (your pricing) = 131.4L
Pump pays for itself in 4.5 months @49L


How did you do your caculations?
10 watts per hour x 24 hours = 240 watts per day.
365 days x 240 = 87,600 watts
87.6 kwatts x .5L (your pricing) = 43.8l
Pump pays for itself in 13.2 months.

"Andy McKenzie" wrote in message
...
"Mickey" wrote in message
...
Get a smaller pump it may pay for itself in electricity.

"Tim Downie" wrote in message
...
Is is possible to use a speed controller (like a light dimmer) with a
small
pond pump?

I have a Bermuda 3000 (3000l/hr) submersible pump that's really a bit
more
powerful than I need. The motor has a solid rotor that appears to be
made
of a ferrite like material.

I know that speed controllers can cause overheating problems with some
motors but given that it's underwater with water bathing the rotor, I
don't
imagine this would be a problem in this case.


Quick calculation - 3000 l/hr pump takes 30 Watts - 1500l/hr pump takes 20
watts, so you save 10 watts switching to a smaller pump. 10 watts costs
about £5 assuming you run the pump 24*7, pumps cost £50, so you only save
money by changing the pump after 10 years!

Of course these numbers are almost certainly wrong!

I thought the best way to control the flow would be to bleed some water
off
before the fountain/filter or whatever is taking too much water.

Andy