Single Speed Pump is Dying. Which 2 Speed to Choose?

[SGinAZ]

Hi All,

My current Hayward Northstar pump is on it's last legs and I would like to upgrade to a two speed motor. Here are the specs on my very basic pool:

10K gallons
A&A in floor cleaning system
Sta-Rite 600 Sq Ft cartridge filter
Hayward Northstar 1.5HP, 1.6 SF, 230v pump (housing is ten years old, motor is six)
2" piping
Pump is about ten feet from the pool and maybe a foot above the water level.
Basic on/off Intermatic mechanical timer
Pump is running six hours/day
Electric rates: $.06 kWh

I have no water features, spa, solar, etc.

I've looked at the new variable speed pumps but with the size of my pool and my electric rates the return on that price premium is quite a ways out there when I compare to a simpler 2 speed system.

With the above information can I get some help on which pump would be a good buy? I've tried to calculate TDH etc but to be honest I'm getting lost in it all. I suspect that my current pump is oversized but perhaps not given the in floor cleaning system. I think I should be looking at a 1 to 1.5 HP pump and one of my key criteria is to be as quiet as possible since the pump is right outside the master bedroom window (quiet the Northstar is not). I think I've narrowed it down to the following models:

Pentair Whisperflo: WFDS-4, WFDS-6 or WFDS-26
Sta-Rite Max-E-Pro: P6RA6YF-206L

I'm really not brand-centric and would be open to a Hayward or Jandy as well.

My plan is to run the new pump at low speed during most of the schedule then kick it up to high speed for a couple of hours to allow the in floor cleaning heads to do their thing each day.

Any advice or comparisons on my options are appreciated.

Thanks!

Sean..

 

[JasonLion]

It sounds like you already know nearly everything you need to know

The WFDS-4 and WFDS-26 are the same pump with different name plates. The WFDS-6 is probably more than you need.

 

[SGinAZ]

Any thoughts on noise level between the Whisperflos and the Max-E-Pro? Also, if I read the specs correctly on the Pentair site, the WFDS-4 pulls 7.8/3.0 amps (high/low?) while the Max-E-Pro pulls 9.2/2.5. Would this make any real world difference? Finally, the flow curves for the two pumps differ as well: B, G for the Whisperflo and A,E for the Max-E-Pro. Am I correct in thinking that the Max-E-Pro has lower flow capacity?

http://www.pentairpool.com/images/produ ... ve_new.gif

 

[mas985]

I wouldn't go by the nameplate ratings for actual power draw. The ratings are simply maximums but don't give a good indication of what the motor will actually draw in operation. If you really want to know what a motor will draw in a typical setup, the California Energy Commission (CEC) has a database of test data located here. I have put the data into a spreadsheet located here which allows you to compare the lifetime costs of various pumps. But to save yourself time, one of the most efficient 2 speed pumps is the WFDS-3/WFDS-24. You don't really need anything larger than a 3/4 HP full rated two speed pump.

 

[SGinAZ]

Thanks for all the input and confirmation I was on the right path. I'm good to go!