New Intelliflo Not Pulling Weir Gate Skimmer Down At Lower Speeds

[Twinzer]

I have a new Intelliflo VS-SVRS pool pump 011017 installed in my pool but at the lower speeds (1100 rpm) it will not pull the weir gate down in the skimmer and it shuts off due to the SVRS. I need to put it up to 1400 rpm in order for it to start but it won't pull in leaves and such unless I put it above 1700rpm. This is all with the solar shut off. Is this common? Is there something wrong with my system or do I need a lighter weir gate - the current one moves fairly easily and does not catch anywhere.

Here is my current set up;

27,000 gallon pool

Compool Cp3810 system

Sta-rite S7M120 filtration system

Solar panels set up on 1sr floor roof

Polaris booster pump for cleaner

I also have no idea how much gallons per minute I am pulling in at what speed in order to determine how long to run the pump.

Any help would be greatly appreciated. Thanks

[dscriterium]

That could be tough to solve. I don't have experience that this would work but you might consider taping a weight on the inside of the weir to make it less bouyant. It's a quick, cheap experiment and if it works, the weight could be mounted permanently with epoxy.

[Mark]

At low RPM, the flow rate decreases substantially so I wouldn't expect the wier door to go down much anyway. Skimming won't work as well at low speed either.

However, it sounds like there might be some excess suction head which is triggering the SRVS so could you describe your system in a bit more detail?

What is the plumbing size and number of pipe runs pool to pad for both suction and return plumbing?

What is the filter pressure and pump wattage at each of the RPM values you mentioned?

The SRVS has a wattage output reading so you could use the spreadsheet I put together that is listed in my sig under pump modeling tools. It will translate RPM and wattage to GPM.

[Twinzer]

Thanks for the reply - I can get this info later today and post.

I'm very much a rookie at this - when you say "...number of pipe runs pool to pad for both suction and return plumbing?" - what exactly does this mean?

Thanks

At low RPM, the flow rate decreases substantially so I wouldn't expect the wier door to go down much anyway. Skimming won't work as well at low speed either.

However, it sounds like there might be some excess suction head which is triggering the SRVS so could you describe your system in a bit more detai

What is the plumbing size and number of pipe runs pool to pad for both suction and return plumbing?

l?

What is the filter pressure and pump wattage at each of the RPM values you mentioned?

The SRVS has a wattage output reading so you could use the spreadsheet I put together that is listed in my sig under pump modeling tools. It will translate RPM and wattage to GPM.

[Mark]

Some pools are plumbed so there is a separate pipe from each skimmer and/or main drain all the way to the equipment pad while other pools are plumbed such that the runs are combined near the pool and then a single run to the equipment pad. Same for the return side, there can be multiple pipe runs from the pad back to the pool. Also, on the return side, a single pipe run can be distributed to multiple eyeball returns.

All of these factor have a bearing on what would be considered "normal" for your setup. But the most important information is the filter pressure, assuming your gauge is in working order.

[Twinzer]

I just have one skimmer, so just one return pipe to the pad. My return goes through the solar and out two eyeballs.

Here are my Intelliflo stats;

1100rpm - 5 1/2 psi - 187 watts

1700rpm - 11 psi - 312 Watts (current recycling speed)

2150 rpm - 16 psi - 600 Watts (solar)

The external diameter of my plumbing is 2 1/4" and the only different plumbing is the booster at 1 3/4"

Thanks very much for any/all assistance!

Some pools are plumbed so there is a separate pipe from each skimmer and/or main drain all the way to the equipment pad while other pools are plumbed such that the runs are combined near the pool and then a single run to the equipment pad. Same for the return side, there can be multiple pipe runs from the pad back to the pool. Also, on the return side, a single pipe run can be distributed to multiple eyeball returns.

All of these factor have a bearing on what would be considered "normal" for your setup. But the most important information is the filter pressure, assuming your gauge is in working order.

[txpoolguy]

generally speaking, it takes about 40 gpm to pull down the skimmer weir. On the lower speeds of the variable speed pump, it may not be moving enough water to accomplish this. This is one of the misconceptions of the Variable Speed pumps. While you can drop the rpm/wattage to a very low point, you may not be circulating enough water for it to be of any benefit. Since every pool is different, you'll have to find the level that is best for your pool. The pressure coming out of the return fittings is also necessary to move the water around the pool, so lower speeds do not accomplish this as fast or perhaps as well as the higher speeds.

[Twinzer]

Hey Mark - I pugged in my numbers into the tool that you provided and the numbers are looking a little weird - like I am pumping less GPM with the higher speed? Any help you can provide would be greatly appreciated. Thanks!

At low RPM, the flow rate decreases substantially so I wouldn't expect the wier door to go down much anyway. Skimming won't work as well at low speed either.

However, it sounds like there might be some excess suction head which is triggering the SRVS so could you describe your system in a bit more detail?

What is the plumbing size and number of pipe runs pool to pad for both suction and return plumbing?

What is the filter pressure and pump wattage at each of the RPM values you mentioned?

The SRVS has a wattage output reading so you could use the spreadsheet I put together that is listed in my sig under pump modeling tools. It will translate RPM and wattage to GPM.

[Mark]

Both the wattage numbers and the PSI numbers that you posted do not look correct for the given RPM values. Wattage will generally increase by the cube of the RPM. So going from 1100 to 1700 RPM should be a 4x increase in wattage but you are only showing 312 watts when it should be more like 900 watts.

Also, 5.5 PSI is at least 13' of head and at 1100 RPM, the pump would be dead head with no flow rate. Also, 11 PSI at 1700 RPM would dead head as well. So something is definitely wrong with some of the numbers or the return is really completely blocked.

Are you feeling water come out of the returns?

Are you using the readout on the Intelliflo to get the wattage and RPM levels?

Are you sure that your filter gauge is reading correctly? Does it go to zero when shut off?

[Twinzer]

I have it set to 1700 at the lowest for recirculation and I can feel water coming out of the returns but it is not a ton (hard to tell). I am using the readout from the Intelliflo unit for both the wattage and RPM.

The filter gauge is working as I just had it replaced and it does go to zero when shut off.

Thanks

[Mark]

Normally, the Intelliflo operating point is fairly predictible. The RPM, GPM, watts and head should all fall on a series of well defined curves. But in this case, it doesn't seem to be.

The RPM and Wattage indicates around 25 GPM but the filter pressure of 11 PSI and 25' of head would indicate a dead head situation. If the total head was around 22', then it would match the wattage calculation of 25 GPM. But even that is fairly low for the RPM and would indicate very restrictive plumbing. This might be why the model isn't accurately representing your situation. But a more important question might be why you have such high head loss in your plumbing.

One thing I forgot to ask was if the filter gauge is well below the water level such as in an above ground pool or an in ground where the pad is located down a hill. This would give a false reading.

Also, do you have any check valves? If so, are they the flapper type or the spring loaded axial type?

[Twinzer]

Hey Mark - the filter gauge is a couple of feet above the pool level. I have a couple of check valves - one on the solar and one on the heater. Here is a link to pics of my set-up to give you a better visual;

http://i25.photobucket.com/albums/c67/Twinzer/photo.jpg

http://i25.photobucket.com/albums/c67/Twinzer/Pool.jpg

Thanks again

Normally, the Intelliflo operating point is fairly predictible. The RPM, GPM, watts and head should all fall on a series of well defined curves. But in this case, it doesn't seem to be.

The RPM and Wattage indicates around 25 GPM but the filter pressure of 11 PSI and 25' of head would indicate a dead head situation. If the total head was around 22', then it would match the wattage calculation of 25 GPM. But even that is fairly low for the RPM and would indicate very restrictive plumbing. This might be why the model isn't accurately representing your situation. But a more important question might be why you have such high head loss in your plumbing.

One thing I forgot to ask was if the filter gauge is well below the water level such as in an above ground pool or an in ground where the pad is located down a hill. This would give a false reading.

Also, do you have any check valves? If so, are they the flapper type or the spring loaded axial type?

[Mark]

There doesn't seem to be anything unusual in your setup but here are a few things to check:

It looks like you can remove the check valves in order to inspect the flapper mechanism. I had one detach on me which created a lot of head loss and reduced flow rates substantially.

When was the last time you cleaned the filter? It might be worth while thing to do.

One more data point might be useful. What was your old pump model and the filter pressure when running?

[Twinzer]

The filter was replaced about 5 months ago so it is brand new - it has not been cleaned since it was installed.

The previous pump was a Sta-Rite Max-E-Glas II and it ran at about 20-22 psi

There doesn't seem to be anything unusual in your setup but here are a few things to check:

It looks like you can remove the check valves in order to inspect the flapper mechanism. I had one detach on me which created a lot of head loss and reduced flow rates substantially.

When was the last time you cleaned the filter? It might be worth while thing to do.

One more data point might be useful. What was your old pump model and the filter pressure when running?

[Mark]

Do you know what size pump it was (e.g. full rated 2 HP) or perhaps the model#?

And the 20-22 PSI was with or without solar?

[Twinzer]

Hey Mark - it was a Sta-rite Max-E-Glas II, model# P4EA6E-186L, 1HP.

It ran at 20-22 psi with the solar on.

Thanks

Do you know what size pump it was (e.g. full rated 2 HP) or perhaps the model#?

And the 20-22 PSI was with or without solar?

[Mark]

The old pump would of had an operating point of around 61 GPM @ 57' of head. On the same plumbing the Intelliflo should have an operating point at 2150 RPM of 46 GPM @ 33' of head and a filter pressure of around 12-13 PSI. So something seems to have changed in the plumbing since you installed the Intelliflo. I would focus on the check valves.

[Twinzer]

Thanks Mark - what do you mean by "operating point"? What should it be doing at 1,700 rpm?

The old pump would of had an operating point of around 61 GPM @ 57' of head. On the same plumbing the Intelliflo should have an operating point at 2150 RPM of 46 GPM @ 33' of head and a filter pressure of around 12-13 PSI. So something seems to have changed in the plumbing since you installed the Intelliflo. I would focus on the check valves.

[Mark]

The operating point of a pump on a plumbing system is where the plumbing head curve crosses the pump head curve. I have an example of a graph which shows how that looks in the Hydraulics 101 link in my signature. These curves are nearly orthogonal so for any given pump at a specific RPM on a given plumbing system, there is only one operating point. So what I did was calibrate your plumbing system based upon what the operating point of your plumbing/pump use to be. I then used the same plumbing system and determined the new operating point with the Intelliflo VF at a specific RPM value. Since the operating point doesn't match what you are seeing, I suspect that something else has changed which is why I suggested looking at the check valves.

When solar is engaged, the head loss of the return side plumbing increases which reduces flow rates. So the numbers I gave for 2150 RPM are for solar. For 1700 RPM, I am assuming that is without solar so I would need to know what your old pump filter pressure was without solar in order to tell you what the flow rate should be the Intelliflo.

However, with 1700 RPM and solar engaged, the operating point would be 36 GPM and 21' of head (7 PSI filter pressure). Guessing at the head loss without solar would put the operating point at 1700 RPM around 52 GPM and 18' of head (5 PSI filter pressure). This is what I might consider being typical of a pool with 2" plumbing. But if you know the pressure of the old pump without solar, I can get a little closer.

[Twinzer]

Hey Mark - I don't know what the old pressure was without the solar but you've given me a lot of good data to work off.

Thanks very much for all your help! I very much appreciate it.

The operating point of a pump on a plumbing system is where the plumbing head curve crosses the pump head curve. I have an example of a graph which shows how that looks in the Hydraulics 101 link in my signature. These curves are nearly orthogonal so for any given pump at a specific RPM on a given plumbing system, there is only one operating point. So what I did was calibrate your plumbing system based upon what the operating point of your plumbing/pump use to be. I then used the same plumbing system and determined the new operating point with the Intelliflo VF at a specific RPM value. Since the operating point doesn't match what you are seeing, I suspect that something else has changed which is why I suggested looking at the check valves.

When solar is engaged, the head loss of the return side plumbing increases which reduces flow rates. So the numbers I gave for 2150 RPM are for solar. For 1700 RPM, I am assuming that is without solar so I would need to know what your old pump filter pressure was without solar in order to tell you what the flow rate should be the Intelliflo.

However, with 1700 RPM and solar engaged, the operating point would be 36 GPM and 21' of head (7 PSI filter pressure). Guessing at the head loss without solar would put the operating point at 1700 RPM around 52 GPM and 18' of head (5 PSI filter pressure). This is what I might consider being typical of a pool with 2" plumbing. But if you know the pressure of the old pump without solar, I can get a little closer.

[Beelzy]

Wow, looking at the pic there is a LOT of plumbing after the pump. The Sta-Rite did better because it had a better Pump Curve.(IMO)

Given the situation that Whisper-Flo is doing as good as it can. The only way to get more flow (I wouldn't worry myself) would

be to clean up the plumbing or put a Sta-Rite V.S. in.

[ThePoolTech]

I have a new Intelliflo VS-SVRS pool pump 011017 installed in my pool but at the lower speeds (1100 rpm) it will not pull the weir gate down in the skimmer and it shuts off due to the SVRS. I need to put it up to 1400 rpm in order for it to start but it won't pull in leaves and such unless I put it above 1700rpm. This is all with the solar shut off. Is this common? Is there something wrong with my system or do I need a lighter weir gate - the current one moves fairly easily and does not catch anywhere.

Here is my current set up;

27,000 gallon pool

Compool Cp3810 system

Sta-rite S7M120 filtration system

Solar panels set up on 1sr floor roof

Polaris booster pump for cleaner

I also have no idea how much gallons per minute I am pulling in at what speed in order to determine how long to run the pump.

Any help would be greatly appreciated. Thanks

[ThePoolTech]

If the main drain line comes into your skimmer you might try plugging off that line. We have plugged off a number of them after installing the Intelliflo pumps. You will be amazed at the difference it can make.

[AFiremanFirst]

I have to ask what may seem like a stupid question! What is a weir gate? In my area all of our skimmers have "floating" weir doors. Hayward tends to be the most common. 10 gpm or 150 gpm, it opens.

[Twinzer]

I have to ask what may seem like a stupid question! What is a weir gate? In my area all of our skimmers have "floating" weir doors. Hayward tends to be the most common. 10 gpm or 150 gpm, it opens.

Same thing I'm talking about - it is a floating weir door. At the lowest intellifo speed it does not get pulled down. thanks