Variable speed pump install

eskewj

Active member
Jan 10, 2014
34
Harrisburg, NC
Hello! I would like to upgrade to a variable speed pool pump.

Here are my design priorities:
  1. Quiet operation
  2. Reliability (proven brand / model)
  3. Ease of fitting into existing plumbing
  4. Energy efficiency
  5. Ergonomics / ease of accessing controls (since VS motors have the timers built-in)
I have a few questions after my research.

#1 - Currently I have a single-speed 3/4 hp Whisperflo with a S.F. of 1.25, or about 0.94 THP. The smallest Pentair VS is 1.5 hp or 2.0 THP. I realize being variable speed, you don’t need to run at full power, but I want full power to be low enough that it doesn’t do any damage to my system since it’s not a question of if, but when, it might get accidentally set to the highest RPM. Should I be worried?

#2 - I keep my pool open year-round and would like to have a thermal switch kick on the pump for freeze protection. Is this possible with a VS motor since the controls are integrated right into the unit?

#3 - This might be a dumb question, but are all pumps by all manufacturers designed to “fit” in the same place if replacing an existing one?

Here is my current setup:

2” pipe
TR-60 sand filter with a filter flow rate of 63 gpm
45 avg ft of head
14,000 gallon in-ground which would be fully cycled after 8 hours @ 30 gpm

Thank you guys as always for your wise counsel!
 

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Divin Dave

TFP Expert
LifeTime Supporter
Oct 2, 2013
5,599
Longview, Texas
Hi,
You'll be shocked at how quiet a VS pump is. I promise.

answers to your questions
1. You wont do anything damage a full speed.
2. Most VS pumps have built in freeze protection. Mine does and I run mine year round. Not sure if that one does or not but probably so. I bet money you can look up an owner manual for it online and find out.
3. There is no guarantee it will fit your existing plumbing, put there is a real possibility that it might.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,023
Bedford, TX
E,

You should buy the 3 HP IntelliFlo... It will not damage anything..

Your main problem is that you will not have an easy time seeing the control panel.. You should buy one of the IntelliFlo's that has the control panel that you can mount to a wall..

The IntelliFlo has the same footprint that your current pump has, and it should be a drop in replacement because your "pretend" unions..

My pump is so quiet at 1200 RPM that when it was new, I often would touch it just to make sure it was still running. :)

You would be making a mistake to buy the Pentair SuperFlo VS..

Thanks,

Jim R.
 

eskewj

Active member
Jan 10, 2014
34
Harrisburg, NC
E,

You should buy the 3 HP IntelliFlo... It will not damage anything..

Your main problem is that you will not have an easy time seeing the control panel.. You should buy one of the IntelliFlo's that has the control panel that you can mount to a wall..

The IntelliFlo has the same footprint that your current pump has, and it should be a drop in replacement because your "pretend" unions..

My pump is so quiet at 1200 RPM that when it was new, I often would touch it just to make sure it was still running. :)

You would be making a mistake to buy the Pentair SuperFlo VS..

Thanks,

Jim R.
@Jimrahbe Wow if I thought the 1.5 hp model would be overkill, the 3 hp model seems even more so. Are you recommending it on the basis of the wall-mounted controls alone? There is a huge difference in cost. Also, what do you mean by “pretend" unions?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,023
Bedford, TX
E,

There is no such thing as overkill when talking about a VS pump.. The larger the pump the more water it moves at a lower speed and the less it costs to run. I recommended the IntelliFlo because it is the gold standard of pool pumps, because you can mount the head remotely (on the newer ones), and because it is a drop in replacement for what you have.

The unions you have are definitely better than no unions, but they are home depot unions and not really designed for pumps. Pump unions screw directly into the pump and have O-Rings around the threaded connection to prevent the drips you often see at the threaded in and out connections of the pump. They look like this...


Thanks,

Jim R.
 

tstex

Silver Supporter
Aug 28, 2012
1,670
Houston, TX
The main thing you want is reliability...all of your other criteria is moot if you have to keep flipping the breaker back on or replacing VS pool pump parts. As Jim stated, get the inteliflo bc you get both reliability and everything else you desired. It will pay for itself over time...and, if you can get something that allows you to program standing right side up, that would be most desirable.
 

eskewj

Active member
Jan 10, 2014
34
Harrisburg, NC
The main reason I'm skittish about getting a larger pump is because of this video:

It explains that if the pump is running at a higher GPM than the filter is rated for, the strain on the motor will wear it out prematurely. So longevity is part of the reliability equation and THP relative to the filter size seems to be a relevant factor.
 

kchinger

Well-known member
Aug 20, 2017
186
Southeast PA
I have a pureline from inyo and like it a lot so far. Plus they seem to sell at decent prices
I've only had my Pureline 165 (1.65 HP) VSP installed for a few days, but I've been happy too. It's also considerably cheaper than a lot of the others ($650 or so). Only $850 if you get it with the remote controller that allows fine tuning and stuff, but not necessary for everyone (I'm fine without it, but I'm young and bending over a bit isn't awful).
 
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Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,023
Bedford, TX
E,

The only time you could pump more GPM than a filter could handle is if you ran the pump at full RPM.. Who in their mind would buy a VS pump to run at max RPM?? The entire point is to run as slow as possible not as fast as possible.

Jim R,
 

markayash

Gold Supporter
Mar 21, 2016
549
Marrietta Ga
I've only had my Pureline 165 (1.65 HP) VSP installed for a few days, but I've been happy too. It's also considerably cheaper than a lot of the others ($650 or so). Only $850 if you get it with the remote controller that allows fine tuning and stuff, but not necessary for everyone (I'm fine without it, but I'm young and bending over a bit isn't awful).
I have found I set program 1 to 2300 and 24 hours and let it run..If I need more or less flow I click the override :) I debated toe control module but decided I didn't need it
 

Darin

Member
May 29, 2015
16
Muscatine/IA
If you are a DIY'er you could save a lot of money and put together a VFD system.
Mate up your existing pump with a 230 Volt input 0.75 hp three phase motor. Depending on you existing power, if 120 Volt, purchase a 0.75 hp Variable Frequency Drive or a 1.0 hp VFD. Many of these 120 Volt VFD's do not have to be derated. If you have 230 240 Volt incoming power buy a 1.5 VFD because these drives have to be derated by about 50%.
These drives mated with the appropriate pump which you already own are much much less money. You can drive your pump at any speed from 0 - 60 Hz, i suggest not going slower than 40% speed which is 24 Hz. I normally run mine at 30 Hz which is 50% speed, (30 Hz is 50% of 60 Hz full speed) A good VFD costs about $150 or less. Your motor cost will be the probably same whether it is single phase or three phase.

The prepackaged systems are just this. They place a VFD inside the package to drive a three phase motor. Your single phase power in, the VFD converts it to three phase which the motor uses to drive the pump. Remember that no single phase pump motor is variable speed. The only real way to have variable speed in our home pools is by utilizing some sort of VFD on a three phase motor.
Either put together your own or go the expensive route and purchase one system which is integrated and when the motor goes bad or the VFD, you have to buy every thing again rather than just one component.

To answer your priorities:
  1. Quiet operation - Very quiet
  2. Reliability (proven brand / model) Stand alone VFD's are the new norm in manufacturing setups. Very reliable.
  3. Ease of fitting into existing plumbing No change. just mount your new motor and run leads to your VFD
  4. Energy efficiency Same as expensive prepackaged Variable Speed.
  5. Ergonomics / ease of accessing controls (since VS motors have the timers built-in) Very easy to use. You can mount the VFD just about any where. It does not have to be right on you pump system. Could be hung on a nearby wall.
I use a 3 hp Teco VFD model FM50 to drive my motor which is a 230 Volt 1.5 HP century three phase.
 

Darin

Member
May 29, 2015
16
Muscatine/IA
Consider that if you purchase an oversized pumping system that you will be also save less money on your electricity. Yes you can buy something that is two times to big and run it at 50%. But why? Buy the correct size and run it at 50%. There is a large diffenced in watts when you compare two times to big vs the correct size at 50%. Sure you could run the big one down to 25% but then you will run into heat issues. And what about the excess speed that you dont use? Well you you just paid extra $$$ for absolutley nothing.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,057
Laughlin, NV
Consider that if you purchase an oversized pumping system that you will be also save less money on your electricity.
You will consume less electricity pumping the same amount of water with a 3 hp VS pump versus a 1.65hp VS pump.
 

Darin

Member
May 29, 2015
16
Muscatine/IA
You will consume less watts pumping a designed 0.75 hp VS system than with a 3 hp or 1.65 hp system. The whole point is to run the VS system at slower speed (50% or 30 Hz, pick your flavor) and only run full speed during manual cleaning and pool opening/closing.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,023
Bedford, TX
I'm curious about your reasoning supporting this statement. Thanks.
Oly,

Because it is a drop in replacement for what he has now, and the main reason is because of the removable control head.. Did you see the location of his current pump??

Thanks,

Jim R.
 
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Darin

Member
May 29, 2015
16
Muscatine/IA
It looks like your current frame is a 46Y on your Whisperflo.

So consider this inexpensive alternative.

From Grainger: Century ¾ HP pool and spa pump motor, 3 -Phase, 208-230/460V, 48Y Frame. SF 1.65 THP: 1.24 Item # 16U462. $221.00

Or

From Grainger: Century ½ HP pool and spa pump motor, 3 -Phase, 208-230/460V, 48Y Frame. SF 1.90 THP: 0.95 Item # 16U462. $201.03

Depending on your current service factor pick the one which is higher with the lowest hp.

Then hook up this VFD to it. Do a google search to buy it. I bought mine from Electric Motors | Motor Controls | VFD | AC Drive but they are so common that there is a lot of competition.

If you presently have 240 V to pump.
Teco/Westinghouse Model L510-201-H1-U $125.00

If you presently have 120 V to pump.
Teco/Westinghouse Model L510-101-H1-U $135.00

Cost of this solution is from $326 to $356. Then add your enclosure. You all ready own a perfectly good pump, why replace it?

Darin
 

Darin

Member
May 29, 2015
16
Muscatine/IA
@Jimrahbe Wow if I thought the 1.5 hp model would be overkill, the 3 hp model seems even more so. Are you recommending it on the basis of the wall-mounted controls alone? There is a huge difference in cost. Also, what do you mean by “pretend" unions?
You are correct the 1.5 hp is overkill. Your pump was designed with an impeller to be driven by your 0.94 THP motor. Thats why you bought a package that size, motor matched to pump matched to pool size.. There is such a thing as overkill when using VS motor/pumps or motors/pumps driven by VFD. Too big and you are wasting watts and running too slow you can/will run into heat issues.