Replacing Pump/Filtration system for a 20,000 pool.

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mh_jenkins

mh_jenkins

0
Jul 27, 2014
25
Lexington, SC
My 19 year old pump/filtration system is ready to be replaced. It is a 20k gallon pool, 3/4 HP motor, 1.5 in pipe with 35 average feet of head, and other components shown in the signature below. I have read the filter needs to be rated for more GPM than the pump/motor combo even when the pump is at max speed.

Currently manually run my pump for just 2 hours a day when the water is clear.

Also, read about the pluses of variable speed motors with timers which is probably what I want but overkill?

What pump/motor/filter combo do you guys recommend for this application?

pool6.jpg
 
How did you get to 35' of head? Note: Head loss is NOT equal to the length of pipe.

It doesn't matter anyway. With your setup, you can just go with the smallest pump possible and a two speed or VS will save on energy. But for your location, a VS may end up costing more over the life of the pump than a two speed unless you get a large rebate from your power company.
 
Hi and thanks for your good reply mas985. The 35' of head was calculated by summing up the length of the 3 incoming pipes (2 skimmers and 1 main drain) into the pump from the pool and dividing that sum by 3.

Your recommendation makes since. Most VS are 3 HP and seem to have too much power on the top end for my setup. The 2 speed smaller pump makes since but would like to get a quality one with a timer as part of the motor. There is the Pentair SuperFlo VS 1.5hp Variable Speed Pool Pump 342000 342001 which is a 3 speed VS that I am considering.
 
mh_jenkins said:
The 35' of head was calculated by summing up the length of the 3 incoming pipes (2 skimmers and 1 main drain) into the pump from the pool and dividing that sum by 3.
Click to expand...
That is the average length of pipe but not total head loss. Head loss is a much more complicated calculation that includes fittings, valves, filter and all other equipment. The length of the pipe only contributes a small amount to total head loss.


But first I would look into any rebates you may get from the power company. Without that and given your location, a two speed would probably make more sense.


Also, the top end of the larger VS pumps don't matter much if you never use full speed. You can set top speed to be anything want. However cost wise, they probably don't make sense anyway.
 
Unless your filter is leaking, I wouldn't be in a big hurry to replace it. If you do decide to replace the filter - the general consensus is to get as big as you can afford / fit in the space - yes a 300 pound sand filter (or larger) is not a bad thing. When you "oversize" your filter, it will go longer between cleanings.

Pump - yes - I'd replace the current motor with a 2 speed. Finding a 115V 2 speed to drive your current wet end might be interesting, but there are replacement pumps that will work (the Pentair Dynamo has a 3/4 and 1 HP 2speed that runs on 115V , maybe a 3/4 HP as well).

A good picture of your pump (especially the name plate) would help alot.
 
Thanks you guys! Makes since for the 2 speed motor. I don't know much about how they operate. Do they have a clock/timer to turn off/on pump?

Also motor is a 3/4 HP 3450 RPM Emmerson and filter is a Sand Tagelus TA40/400 rated at 40 GPM.

Here is a picture of it... and the back cover is off the motor during that picture. It is back on now.

pool2.jpg
 
If your water is fine @ 2hrs/day - great !! Turnover is a thing for commercial pools to be worried about.

That pump sort of looks like an early version of a Hayward SuperPump or maybe a SuperPump II.

what kind of power are you using (120 V or 240 V ) ?

FYI - if I was going to do it over again - I would go with a 1 HP 2speed pentair Superflo (fits right in for a Hayward superpump) for my own pool.
 

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Intermatic t 104 timer, yes will do. And 1 HP 2speed pentair Superflo. Yus. The pump, i think is using 120 V? It has a green and Black and copper wire attached to it. The breaker is double wide. I will measure it with my volt meter and find out.
 
The SuperFlo is a 220V pump. However, if you have 220 to the breaker box, and space for a 220V 2 pole breaker - not a difficult conversion to do. Just move the white wire over to the other pole of the 220 V breaker instead of the neutral bar (and mark the white on both ends so people recognize it is hot and not neutral).

As I was saying - Pentair has their 2 speed Dynamo models which ARE 120V.
 
The motor is surely not working anymore and will not stay spinning. Used a drill with a common bit to get it started but even when primed with water it will slow to a stop then just hum and start to show some smoke. So, I just ordered a 3/4 HP Pentair Dynamo 2 speed... more to come. Will have to rewire the power feed from a 240 to a 120 V supply. Also will order a new flexible hose between the pump and sand filter instead of PVC.
 
Much respect for you guys. Thanks much for your good input. superhsd - ty bud! The electric motor died so I replaced it with a new Pentair 1 HP two speed motor for about $250. It is soooooo much better than the old pump. The high speed is powerful and pulls water better than the old pump and the low speed is about 1/8 (guess) of full speed making it nice to keep the pump running over night for crystal clear water and economical electric bills.

Tried to upload a picture.. but cannot figure out this quota thingy on TFP.

Anyhow... the pool is happy.
 
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