I am new to the forum - finding it informative with knowledgeable and helpful members.
The pool and equipment came with the house. Both are old and basic. Exception is Speck S90 230V 3/4" pump thatI installed 12 years ago to replace a larger pump that wasn't working well.
Our pool use and needs are basic and limited. Open June - September. I do the upkeep, which now includes needing a new pump to
replace the Speck S90. It operated very well until late last season when motor lost output. Very reduced water flow. Some internal pump
components also found to be worn, so we are opting for a new pump, possibly a 2 spd rather than VS. Leaning toward 2 spd as it's simpler overall and we could run it at reduced speed the majority of time provided 1725 rpm operation offers adequate circulation and filtration.
I foresee running the new pump at reduced speed almost entirely, say 12-14 hrs/day more or less, depending on what's needed for a full turnover. Full speed operation for an hour or two after back washing the filter or shocking. However, I have three concerns:
1. I've read that DE filters do not work very well with long hours at relatively low motor speeds (1725 rpm). Is that accurate?
2. Performance curves for small 2 spd pump/motors generally chart flow from maximum 20-25 ft total head to zero. And flow rates are
relatively low even with very low total head. When our DE filter is clean, pressure is around 12 psi, or roughly 28 ft total head
(12 x 2.31).
With this amount of "real world" total head, is it possible that 1725 rpm would move zero to very little water? Or, what sort of flow
would be realistic for a 1-1/2 hp 2 spd pump at 1725 rpm?
3. A step up in motor size could improve low speed water flow, but the size of the return line is a constraint. I don't want to stress the
filter components or the motor.
Thanks in advance for comments and suggestions.
The pool and equipment came with the house. Both are old and basic. Exception is Speck S90 230V 3/4" pump thatI installed 12 years ago to replace a larger pump that wasn't working well.
Our pool use and needs are basic and limited. Open June - September. I do the upkeep, which now includes needing a new pump to
replace the Speck S90. It operated very well until late last season when motor lost output. Very reduced water flow. Some internal pump
components also found to be worn, so we are opting for a new pump, possibly a 2 spd rather than VS. Leaning toward 2 spd as it's simpler overall and we could run it at reduced speed the majority of time provided 1725 rpm operation offers adequate circulation and filtration.
I foresee running the new pump at reduced speed almost entirely, say 12-14 hrs/day more or less, depending on what's needed for a full turnover. Full speed operation for an hour or two after back washing the filter or shocking. However, I have three concerns:
1. I've read that DE filters do not work very well with long hours at relatively low motor speeds (1725 rpm). Is that accurate?
2. Performance curves for small 2 spd pump/motors generally chart flow from maximum 20-25 ft total head to zero. And flow rates are
relatively low even with very low total head. When our DE filter is clean, pressure is around 12 psi, or roughly 28 ft total head
(12 x 2.31).
With this amount of "real world" total head, is it possible that 1725 rpm would move zero to very little water? Or, what sort of flow
would be realistic for a 1-1/2 hp 2 spd pump at 1725 rpm?
3. A step up in motor size could improve low speed water flow, but the size of the return line is a constraint. I don't want to stress the
filter components or the motor.
Thanks in advance for comments and suggestions.