Existing 1.5 HP motor kept dying about once a year (bearings every time), I've finally lost it and decided to replace it.
The question is, was the pump sized correctly?
Here's what I have so far:
- Spa size is somewhere between 1100 and 1500 gallons;
- Head is about 60ft, if I'm getting it right (10ft straight from the pump to the skimmer, 13ft straight from the pump to the drain, 7 jets, heater);
- Filter is marked as "37.5 GPM public, 100GPM residential pools";
- Plumbing is 1.5".
Wanted to install a two-speed pump initially, considered SuperFlo 340043 and WhisperFlo 11522 to run them at low speed, but then looked at performance curves and got totally confused.
First of all, it looks like neither of these pumps will work properly at low speed - 11522 curve starts at about 25ft, and 340043 curve starts at 20ft.
Second, it looks like 11522 will overrun the filter, producing something about 100GPM at head of 60ft, and if it is, in fact, less, then oops.
Reading the discussions, I see that IntelliFlo 11018 constantly pops up as a reasonable upgrade from WhisperFlo, and it looks like it can be programmed to match the rest of the equipment. Does this make sense?
Since it's a chance to rework the plumbing, what measuring devices would I want to install to keep an eye on how well does the equipment perform? Flow meter? Ampere-meter?
Since the high head requirement for spas is dictated by jets, would the filtering work correctly at lower speeds? How do I calculate/determine where is the go/no go threshold?