Intelliflo 4 x 160 and Pentair Legend RPM requirements

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wardsntx

wardsntx

0
Jun 18, 2007
221
Spring, Texas
ok,

I am trying to make this new pool run a t the most efficient rate possible. Currently my pump runs 12 hours at 2100 rpm. The first 3 hours my pool is on, the Pentair Legend runs for 3 hours at 2300 rpm...

1. Is there a minimum RPM setting for the Legend to actually work (can't find this anywhere onPentair web site)

2. In order to make the 4 x 160 worth the money, should I decrease the rpm setting on the pump to maybe 1600 - 1800 rpm? The pool is about 13,500 gallons and the Spa is another 530. I want to make sure I get at least 1 - 1/2 turnovers a day.

If anyone has any advice, it would be greatly appreciated.

KTDave...since we have the similar setup, what have you found to be an efficient setting?

Thanks!
 
FWIW,

well you want it to pump about 14,000 gallons to 21,000 gallons a day. for 1 to 1 and 1/2 turn overs

right now your probably running close to 30GPM to filter 21,600 gallons per day, if you want it to turn over once a day you could slow down your GPM to 20 if you want it to run for 12 hours a day,

if you want it to run for 6 hours a day you would have to double your gpm to 40gpm, for 1 turnover, and 60GPM for 1 and 1/2 turn over.

i dont have one but i am thinking of upgrading to one, this is just simple math, i have no experties in this area, im also not sure what your rpm would be at these speeds.
 
Jay,

My "main" setting is 1600 RPM and the Legend seems to work fine. I have noticed that sometimes on lower speeds it will spin on it's side and just sit there and put on a "breakdancing" exhibition.
 
I believe that the Intelliflo will use less total energy if you run it at a lower speed for a longer time. So if you want 1 1/2 turns a day run it at the lowest speed that gets you at least 14.5 GPM 24 hours a day. If the lowest speed is more than 14.5 GPM then don't run 24 hours a day. If you only have the 4x160 then figuring out GPM takes a little guess work.
 
mas985 seems to be able to work out TDH and flow rates from a couple of filter PSI measurements at different speeds but I don't know how to do that. Looking around at reports from people who have the full IntelliFlo Pro with the GPM sensor it seems that the very lowest speed gives 15 to 20 GPM for a couple of people.
 
If you are game, the best thing to do is install a flow meter.

Otherwise, if you are looking for a rough answer, flow rates in GPM are usually between 1/38th and 1/28th of the RPM setting. So 2100 RPM is between 55 and 75 GPM.

To get closer, I would need to know the following for a set configuration:

For a given RPM value, what is the filter PSI.

Also, details on plumbing system for the suction side and return side plumbing. Number of runs pool to pad and the pipe size. Also, the pad equipment. Even with all of the that, it is tough to get real accurate but I might be able to reduce the range a bit.
 
Jay,
I am about to install a flowmeter much like the one discussed HERE. Once I do this, I can give you some very close approximations of RPM vs GPM for your pool since we have very similar setup.

Or, if you would like to install one of these on your system, the best price I've found is HERE. You need a 28 inch straight run of PVC pipe to install this on for this to be accurate.

I'll keep you posted when I install mine.
 
ktDave,

I would be interested in your data as well. I've got a 4x160 with an approx 13,000 gal IG. I've been wanting to install a flow meter, but I don't have a suitable section of pipe.

I do have a vertical run that is almost 20 inches, but the vertical flow models from Blue-White only measure from 40-150 GPM. For our purposes, I think we'd much rather have the 15-70 GPM model.

Also, please note that Blue White only specs their flow meters at +/- 10% accuracy. I'm not sure if this is 10% of full scale or 10% of reading.
 
peterl1365 said:
ktDave,

I would be interested in your data as well. I've got a 4x160 with an approx 13,000 gal IG. I've been wanting to install a flow meter, but I don't have a suitable section of pipe.
Click to expand...

I'll keep you posted. It may be a few weeks before I get to it.
 

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Jay,

I'm just curious -- when your Pentair Legend is running, do you have all the flow from the pump going to its dedicated line so you have some sort of valve that goes between your regular returns for normal circulation and then switches to the dedicated line when the Legend is running? Do I have that right?

I have ThePoolCleaner on a dedicated line and switch to it for cleaning. I got that because I wanted to use less energy and find that at 15 GPM (the lowest my Pentair Intelliflo will go) I get just over 14 wheel RPM from the cleaner which is at the high end of its 11-14 RPM recommended range, but seems to work fine and doesn't trigger the pressure relief valve. My pump is at 540 Watts when running this cleaner since the cleaner was designed to work without a separate booster pump (i.e. it needs less pressure/flow to operate). It seems that to get 15 GPM through the dedicated line without the cleaner attached is a pressure of around 4 PSI while with the cleaner attached it's 11 PSI so the difference, 7 PSI, is from the resistance of the cleaner and is the pressure required at the return outlet to have 15 GPM flow and 14+ wheel RPM.

Richard
 
Now I get it. I thought you were thinking of removing your booster pump completely and just using the 4x160 to power the cleaner. That's what confused me and was why I wrote what I did. I essentially got rid of my booster pump and used the IntelliFlow switched to the dedicated line via a valve. That saves the most energy by far, but does require a cleaner that needs lower pressure to operate (such as ThePoolCleaner).

OK, so in your situation the booster pump will increase the pressure in the dedicated line to your Legend since it has a lot of resistance, being a pressure-side cleaner that expects a booster pump. The question then becomes how low your 4x160 can go in its GPM output to provide enough water to the booster pump and to the regular returns. I suspect that what will happen is that as you lower the 4x160 output (by lowering its RPM) that the total output will decrease and the suction side of the booster pump will divert more of the water its way. So at some point, you will get to very little output on the regular returns and the pressure-side "head" seen by your regular pump would go way down.

The Pentair booster pump is a 3/4 HP pump with a 1.5 service factor producing a minimum of 50 PSI at 12 GPM. So that means that when your Legend cleaner is running (so the booster pump is on) that you can turn your 4x160 way down probably to a flow rate of around 20 GPM though not much lower than that and perhaps you have to go a little higher up to 30 GPM. This assumes that the booster pump will be taking around 12 GPM of the total flow, leaving the rest for the regular returns and providing the needed pressure for the 4x160. You may have to experiment to see how low the flow can be before either pump has a problem, but I'm guessing that 20-30 GPM will probably work and will be very energy efficient, at least for the IntelliFlo (i.e. most of the energy will be used by the booster pump).

Others have answered the question of what you can do with the 4x160 when the cleaner and booster pump are off. Basically, the IntelliFlo has a rather broad sweet spot of energy efficiency in the range of around 15-26 GPM though this varies depending on your specific piping configuration.

Richard
 
Thanks Richard...

In another post I asked why I was getting air bubbles in the return line closets to the cleaner attachment in the pool.

I didn't notice the air bubbles in the line when the pump was first started and ran full speed for 24 hours. But after decreasing the pump speed and setting the Intelliflo up, is when I noticed.

I had a few replies saying it could be a leak, but I really think it has something to do with the cleaner and the return configuration....I actually noticed yesterday when putting the LEgend back in the pool after a full day of swimming, that when I attached it, I must not have bled all the air out of the line and I got two big burst of air bubbles out of the return nozzle closest to the cleaner...this is the only return line that has any bubbles...and they continue for the entire cleaning cycle although very tiny....but they stop as soon as the 3 hour cleaning cycle is done....


Any thoughts on this? The return line for the cleaner is seperate, so this is confusing to me, and I am not convienced there is a leak anywhere since the only time there has been bubbles is sine reducing pump RPM's and only during the cleaning cycle.
 
Do you know your pump's RPM when you start seeing the bubbles coming out of the dedicated return line for the cleaner? Also, when the cleaner and booster pump are on, have you felt the flow from the regular returns -- is it barely noticeable or just a light flow or what? I'm guessing that if the flow from the 4x160 is too low, then the booster pump isn't getting enough flow, though I would guess that would cause cavitation (which is bad and means a vacuum is created on the suction side that would then collapse at the pump impellers possibly damaging them) and not air bubbles. So actual air bubbles out of the return is a mystery to me. I don't know where the air would be coming from nor why it would only occur at low flow rates from the 4x160.

Richard
 
The pump is set at 2300 RPM when the cleaner comes on...Should be plenty enough. There is decent flow out of the returns when the cleaner is on.

I am actually reprogramming the cleaning cycle for the last 3 hours tomorrow night instead of first thing on start up. I will look in the morning to see the bubbles are still there then when the pmp kicks on.
 
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