A newbie whose disillusioned by VS pumps

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Mike1000

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Feb 12, 2023
9
Florida
Variable Speed pool pumps the pros and cons as I see them.

In 2019 my old single speed 110 V AC pump started leaking and had to be replaced. I was 'persuaded' that the way to go was by replacing it with a variable speed Pentair pool pump that cost around $1,000 as they allegedly would pay for themselves in a few years by savings on electricity bills. 3 years on I've seen little difference in running costs and for the past year a lot of aggravation with the old GFCI tripping. So far its cost me over $1,000 to get a new GFCI & Housing fitted next to the pump and new cable to the main panel to meet current code but the tripping issue is still present. So is the problem the pump ?

Here lies the problem that I see as, variable speed pumps cost a lot more than a 110 volt (or 230 volt) simple induction motor pump as first the 110 volts AC has to be rectified to 110 DC which is then used to power a variable frequency inverter (drive) that supplies an induction motor with a variable frequency & voltage drive depending on the selected RPM by the user. At stop the frequency is 0 Hz and there is no voltage but both parameters are ramped up to give a pump RPM of around 1500 RPM for low speed lower energy use for most of the time and up to 3450 RPM for high speed when cleaning the pool.

That's the advantages but there is one parameter that seems to be overlooked and that's the design of the inverter for pool pumps when GFCI's have to be used. Sold state inverters have been around a long time for battery back up with computers and its worth starting there to look at a potential downside. You can purchase 1500 VA UPS (Uninterrupted Power Supply) for around $200 that when your power goes off, you can run a desktop computer for up to 1 hour from a UPS which have 2 small lead acid batteries, a charger to keep them charged up and a fixed frequency/voltage Inverter to convert 12 Volts (or 24v) to 110 volts when main power goes.

The AC from your electricity company is a pure sine way and normally there is no 'noise' or interference present that affects any household equipment. In rare cases, one can fit line filters to clean it up if there's a problem. However, inverters are 'noisy' by nature due to the fact that the simulated sine wave is created by high power semiconductors turning a DC voltage on and off at different levels, intervals and different points along the 360 degrees of a sine wave. Whilst power from the electricity company comes from from turbine/generators and produces a perfect sine wave, the simulated sine wave from inverters is a 'stepped' sine wave and that produces noise. For most appliances, like phone/tablet chargers, computers, lap tops, TV's, Hobs, Ovens etc the noise has no effect, however there is some anecdotal evidence that noise from the pumps inverter might trip GFCI's. It should be noted that pump inverters that vary their frequency output will produce 'noisier' sine wave at lower RPM (frequency) than at a higher RPM or frequency.
The rated power of this pump is claimed to be a max of 12 amps or so, far more than one used in a UPS which always runs at 60 Hz anyway.

So far I've tried new cabling, a new GFCI, ferrite noise suppressors on the 3 wires between the pump and GFCI and still it trips at random every day or so. Perhaps if this Pentair Pump remembered the time I could live with it but like Microwave ovens it doesn't remember the time.

One other oddity is when the pump first comes on in the morning. Its supposed to go full speed at 3500 or full speed to prime the pump and then go to program 1 of 3. It does that as the RPM drops to 2500 which I have it set for but a few minutes later the pump will stop, wait 10 secs or so and then ramp up again. It may repeat this for 3-5 times before settling down and running normally unless a random trip happens.

I've had two attempts to get answers from Pentair about this odd behavior with no explanation and as far as the GFCI is concerned I've got nowhere. A blog site reports similar issues over the GFCI with claims that Pentair recommend Siemens GFCI's rather than Squard D GFCI's. The response I got from Pentairs support site over GFCI's was -

"Also regarding the breaker we do test all units with siemens breakers and they work the best for our units. we highly recommend using the, and the correct size as well"

Needless to say there was NO warning to use Siemens GFCI's rather than SquareD in the installation guide and their response doesn't highlight a problem with SquareD.

In conclusion -

Is it a GFCI incompatibility issue ? I don't know and Pentair refuse to comment !

Have the electronics gone crazy in the Pump ? It might be as the tech guy couldn't explain that peculiar start up sequence where it started and stopped for no reason.

So, I'm junking this over prices and worthless VS pump and fitting a simple 2 speed pump at 1/3rd the cost and while I'm at it, I'll have installed an Alexa ready Wi-Fi timer at waist height instead of getting down on my knees to use the crappy key pad that's on the pump. At least I can use my phone to change times if needed.

I forgot to mention, its a very noisy pump this Pentair pump compared to the ancient one that died in 2019 after giving good service. If anyone knows of a fix or suggestion, I'd welcome it.

Thanks - Mike
 
Mike1000 said:
Variable Speed pool pumps the pros and cons as I see them.

In 2019 my old single speed 110 V AC pump started leaking and had to be replaced. I was 'persuaded' that the way to go was by replacing it with a variable speed Pentair pool pump that cost around $1,000 as they allegedly would pay for themselves in a few years by savings on electricity bills. 3 years on I've seen little difference in running costs and for the past year a lot of aggravation with the old GFCI tripping. So far its cost me over $1,000 to get a new GFCI & Housing fitted next to the pump and new cable to the main panel to meet current code but the tripping issue is still present. So is the problem the pump ?

Here lies the problem that I see as, variable speed pumps cost a lot more than a 110 volt (or 230 volt) simple induction motor pump as first the 110 volts AC has to be rectified to 110 DC which is then used to power a variable frequency inverter (drive) that supplies an induction motor with a variable frequency & voltage drive depending on the selected RPM by the user. At stop the frequency is 0 Hz and there is no voltage but both parameters are ramped up to give a pump RPM of around 1500 RPM for low speed lower energy use for most of the time and up to 3450 RPM for high speed when cleaning the pool.

That's the advantages but there is one parameter that seems to be overlooked and that's the design of the inverter for pool pumps when GFCI's have to be used. Sold state inverters have been around a long time for battery back up with computers and its worth starting there to look at a potential downside. You can purchase 1500 VA UPS (Uninterrupted Power Supply) for around $200 that when your power goes off, you can run a desktop computer for up to 1 hour from a UPS which have 2 small lead acid batteries, a charger to keep them charged up and a fixed frequency/voltage Inverter to convert 12 Volts (or 24v) to 110 volts when main power goes.

The AC from your electricity company is a pure sine way and normally there is no 'noise' or interference present that affects any household equipment. In rare cases, one can fit line filters to clean it up if there's a problem. However, inverters are 'noisy' by nature due to the fact that the simulated sine wave is created by high power semiconductors turning a DC voltage on and off at different levels, intervals and different points along the 360 degrees of a sine wave. Whilst power from the electricity company comes from from turbine/generators and produces a perfect sine wave, the simulated sine wave from inverters is a 'stepped' sine wave and that produces noise. For most appliances, like phone/tablet chargers, computers, lap tops, TV's, Hobs, Ovens etc the noise has no effect, however there is some anecdotal evidence that noise from the pumps inverter might trip GFCI's. It should be noted that pump inverters that vary their frequency output will produce 'noisier' sine wave at lower RPM (frequency) than at a higher RPM or frequency.
The rated power of this pump is claimed to be a max of 12 amps or so, far more than one used in a UPS which always runs at 60 Hz anyway.

So far I've tried new cabling, a new GFCI, ferrite noise suppressors on the 3 wires between the pump and GFCI and still it trips at random every day or so. Perhaps if this Pentair Pump remembered the time I could live with it but like Microwave ovens it doesn't remember the time.

One other oddity is when the pump first comes on in the morning. Its supposed to go full speed at 3500 or full speed to prime the pump and then go to program 1 of 3. It does that as the RPM drops to 2500 which I have it set for but a few minutes later the pump will stop, wait 10 secs or so and then ramp up again. It may repeat this for 3-5 times before settling down and running normally unless a random trip happens.

I've had two attempts to get answers from Pentair about this odd behavior with no explanation and as far as the GFCI is concerned I've got nowhere. A blog site reports similar issues over the GFCI with claims that Pentair recommend Siemens GFCI's rather than Squard D GFCI's. The response I got from Pentairs support site over GFCI's was -

"Also regarding the breaker we do test all units with siemens breakers and they work the best for our units. we highly recommend using the, and the correct size as well"

Needless to say there was NO warning to use Siemens GFCI's rather than SquareD in the installation guide and their response doesn't highlight a problem with SquareD.

In conclusion -

Is it a GFCI incompatibility issue ? I don't know and Pentair refuse to comment !

Have the electronics gone crazy in the Pump ? It might be as the tech guy couldn't explain that peculiar start up sequence where it started and stopped for no reason.

So, I'm junking this over prices and worthless VS pump and fitting a simple 2 speed pump at 1/3rd the cost and while I'm at it, I'll have installed an Alexa ready Wi-Fi timer at waist height instead of getting down on my knees to use the crappy key pad that's on the pump. At least I can use my phone to change times if needed.

I forgot to mention, its a very noisy pump this Pentair pump compared to the ancient one that died in 2019 after giving good service. If anyone knows of a fix or suggestion, I'd welcome it.

Thanks - Mike
Click to expand...
The cost savings for a variable speed pump are when you run it at a reduced speed, which provides better filtering and less noise. How fast have you been running the pump? I run mine 24x7 and almost don’t notice any difference in electric bill. It’s maybe $20/month extra at most. Hard to tell cause when the pools open, the AC is usually on as well. If the GFCI is tripping, there’s a ground fault problem somewhere or a bad breaker. Very remote chance the brand of breaker is an issue. How large is your pool?(wondering why it’s run at 120V) I don’t use a GFCI on any of my pool equipment so I’m not familiar with it in that context.
 
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Mike,

You did not say what pump you have, but I assume it is an IntelliFlo pump, is that correct?

It is your pump and you can do whatever you like, but... What you say is not the norm and some of what you say indicates that you are trying to run a VS pump at full speed and expect to save money, which is just not true.

I have three 3 HP IntelliFlo pumps and they have been running 24/7, mostly at 1200 RPM. One is over 10 years old, one over 8 years old, one right at 7 years old. They are all powered by Pentair GFCI breakers and they have never, not once, popped the breaker for any reason.

All three pumps are original and are so quiet at 1200 RPM that you almost have to touch to make sure they are still running.

Running 24/7, cost me less than $20 bucks a month, and my pumps are old. Newer IntelliFlo pumps are even more energy efficient.

You don't get any advantage running a VS pump at 3450 RPM. At that speed they are about as noise as single speed pump and cost the same to run as a single speed pump.

Most people never have a GFCI issue using the IntelliFlo. A few people have, mainly because their electrical power is very noisy and combined with the noise that a VS pump can add to the AC line, it can cause the GFCI to randomly pop. Installing the Pentair GFCI Breaker normally takes care of this issue.

You should not have to run your pump at 3450 to get it to prime. The fact that the pump has to 're-prime' is more of a plumbing issue and not a pump issue.

In any case, if all three of my pumps failed tomorrow, they would be replaced with three new ones the next day.

If you want, I can dig up another 50K people who love there IntelliFlo pumps and probably three that don't . I have no clue why you are having issues, but I really doubt is it the pump all by itself.

Sorry you are having issues and hope your switch back to a single speed or two speed pump works well for you.

Thanks,

Jim R.
 
The pump installation manual specifies that there is a Pentair GFCI breaker available, which is the same as this:

www.homedepot.com

Siemens 20 Amp Double Pole Type QPF2 GFCI Circuit Breaker US2:QF220AP - The Home Depot

Prevent a ground fault in construction applications like spas, hot tubs, kitchens or bathrooms with this Siemens Double Pole Type QPF GFCI Circuit Breaker.
www.homedepot.com

20 Amp Double Pole Type QPF2 GFCI Circuit Breaker.

The Pentair breaker is made by Siemens.

This breaker resists false tripping because it is shielded to prevent RF interference.

What model is your pump?

Siemens GFCI circuit breakers are UL Listed and CSA Certified as Class A devices. These circuit breakers offer the new Self-Test and Lockout feature as required by UL 943, enabling the GFCI to automatically and continuously test itself to ensure that it is working properly. If it is detected that the device has been compromised, the device trips itself and locks out the homeowner from resetting the device, reducing the possibility of the homeowner incorrectly assuming that the device was tripped to prevent a ground fault.

Double pole, 240-Volt, 20 Amp GFCI circuit breaker

10 kA interrupting rating

Includes self-test as required by UL 943 as an added safety feature

Suitable for a variety of construction applications including spas, hot tubs, kitchens, bathrooms, etc.

Resists false tripping (shielded to prevent RF interference)

Provides Class A GFCI protection

White line neutral (pigtail) must be connected to the panel neutral for the device to function.
Click to expand...

1676244901364.png


pa220gf.jpg



1676244617339.png

1676244542779.png
1676244443073.png

www.pentair.com

GFCI Circuit Breakers

Ground fault circuit interrupter (GFCI) circuit breakers work faster and at more sensitive thresholds than conventional household circuit breakers. Required by the National Electric Code (NEC) standards for pool pumps, these GFCI breakers are the right choice in load centers supporting...
www.pentair.com www.pentair.com


 
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The GFCI issue is pretty well known. It’s a consequence of changes in the national electric code whereby the minimum ground fault current (leakage from hot to ground) was reduced to no more than 5mA before the circuit trips. You are quite correct that the VSD’s on these pumps can create enough noise on the input power lines to cause sensitive GFCI breakers to trip. Pentair has recommendations for breakers that are less sensitive to the noise. It can be very frustrating to have breakers trip but if your input power is noisy to begin with then that doesn’t help. I live at the “end of the line” in terms of our electric utility and our power is not as clean as it could be (frequency drift and high frequency noise), but my IntelliFlo pump has never had an issue.

As far as priming goes, the IF will only ramp up to prime speed (which you can limit to any speed up to 3450RPM … my max speed is set to 3000) when it detects loss of prime. That usually a plumbing issue. You can also set the sensitivity to priming loss detection as well and set the amount of time the pump will stay at priming speed. I have both of those parameters set so that the pump only primes for 10secs at startup (there’s no need for a long prime because my plumbing always has water in it) and the sensitivity is set higher so it doesn’t accidentally think it’s lost prime. The IntelliFlo manual has all of these settings detailed.

What you describe certainly sounds like a royal PITA but it doesn’t sound like it’s the pump’s fault so much as something squirrelly in your electrical setup and possibly your plumbing. One and 2-speed pumps are basically being phased out of existence by DOE regulations so at some point in the very near future all pool pumps will be VSPs.
 
Do you have an oscilloscope that you can put on the line to see what the waveform looks like and how distorted it is getting?

Can you make a video of that and post it so we can see it?
 
Jimrahbe said:
Mike,

You did not say what pump you have, but I assume it is an IntelliFlo pump, is that correct?

It is your pump and you can do whatever you like, but... What you say is not the norm and some of what you say indicates that you are trying to run a VS pump at full speed and expect to save money, which is just not true.

I have three 3 HP IntelliFlo pumps and they have been running 24/7, mostly at 1200 RPM. One is over 10 years old, one over 8 years old, one right at 7 years old. They are all powered by Pentair GFCI breakers and they have never, not once, popped the breaker for any reason.

All three pumps are original and are so quiet at 1200 RPM that you almost have to touch to make sure they are still running.

Running 24/7, cost me less than $20 bucks a month, and my pumps are old. Newer IntelliFlo pumps are even more energy efficient.

You don't get any advantage running a VS pump at 3450 RPM. At that speed they are about as noise as single speed pump and cost the same to run as a single speed pump.

Most people never have a GFCI issue using the IntelliFlo. A few people have, mainly because their electrical power is very noisy and combined with the noise that a VS pump can add to the AC line, it can cause the GFCI to randomly pop. Installing the Pentair GFCI Breaker normally takes care of this issue.

You should not have to run your pump at 3450 to get it to prime. The fact that the pump has to 're-prime' is more of a plumbing issue and not a pump issue.

In any case, if all three of my pumps failed tomorrow, they would be replaced with three new ones the next day.

If you want, I can dig up another 50K people who love there IntelliFlo pumps and probably three that don't . I have no clue why you are having issues, but I really doubt is it the pump all by itself.

Sorry you are having issues and hope your switch back to a single speed or two speed pump works well for you.

Thanks,

Jim R.
Click to expand...
Thanks for replying, it is an intelliflo pump but the pump program has been roughly 4 hours from 8.00 till midday at 2500 RPM, then at 1500 RPM for 3 hours and then 3000RPM for 2 hours. The only pattern (if any) that I've noticed is that the GFCI tends to trip at low RPM's not high RPM's. Thats comensurate with the higher noise levels from a Variable Frequency/Voltage Drive at low speeds or when starting up. I'm running it for 9 hours maximum whereas previously I ran a single speed pump of lower HP for the same duration. From observations made recently on blog sites the savings only seem to come in if you're running a pump for 24 hours a day which I've never done. I blame myself for not researching VS pumps enough. I'll be monitoring my power bill when I replace the VS pump for a fixed speed pump to see if there's any major difference.

My issue is really with Pentair as their installation guide doesn't demand you use a Pentair GFCI as none exist to my knowledge as their tech support just recommended Siemens over SquareD but didn't say why. A GFCI of any manufacture has to meet code and if its too sensitive then different factors could be at play. Added to the GFCI issue is the repetitive priming sequence it does intermittently which Pentair couldn't explain either.

When I was still working, I supported computer & data communication products around the globe and like all companies, from time to time we had product problems that I had to troubleshoot on and occasionally report a design flay to our designers. If necessary I even had to 'kick Rear' at HQ to find answers and liase with the companies local support people to try and pin down a pattern and cause. With Pentair, I feel I'm getting the brush off hence I've given up with them.

Regards, Mike
 

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JoyfulNoise said:
The GFCI issue is pretty well known. It’s a consequence of changes in the national electric code whereby the minimum ground fault current (leakage from hot to ground) was reduced to no more than 5mA before the circuit trips. You are quite correct that the VSD’s on these pumps can create enough noise on the input power lines to cause sensitive GFCI breakers to trip. Pentair has recommendations for breakers that are less sensitive to the noise. It can be very frustrating to have breakers trip but if your input power is noisy to begin with then that doesn’t help. I live at the “end of the line” in terms of our electric utility and our power is not as clean as it could be (frequency drift and high frequency noise), but my IntelliFlo pump has never had an issue.

As far as priming goes, the IF will only ramp up to prime speed (which you can limit to any speed up to 3450RPM … my max speed is set to 3000) when it detects loss of prime. That usually a plumbing issue. You can also set the sensitivity to priming loss detection as well and set the amount of time the pump will stay at priming speed. I have both of those parameters set so that the pump only primes for 10secs at startup (there’s no need for a long prime because my plumbing always has water in it) and the sensitivity is set higher so it doesn’t accidentally think it’s lost prime. The IntelliFlo manual has all of these settings detailed.

What you describe certainly sounds like a royal PITA but it doesn’t sound like it’s the pump’s fault so much as something squirrelly in your electrical setup and possibly your plumbing. One and 2-speed pumps are basically being phased out of existence by DOE regulations so at some point in the very near future all pool pumps will be VSPs.
Click to expand...
Best answer so far, thanks. My beef is really with Pentair for not flagging up their preference for using Pentair GFCI's and with another post specifying the Pentair version, I immediately noticed it was a double pole GFCI unlike my single pole one (both old and new). Again, no Pentair install guide mentioned this.

I still question the energy efficiency between VS pumps and single/dual speed pumps as surely it depends on how the timer is programmed. IMO, a 1 HP pump used at the lower speed say 1500 RPM for 8 hours a day shouldn't use any more power than a VS pump programmed for 24 hours use at variable speeds. At any given speed, a VS pump has more losses converting AC to DC and again DC back to to variable frequency/voltage AC for a 3 phase pump.

I'd certainly be interested to see real studies on this.
 
Mike1000 said:
Best answer so far, thanks. My beef is really with Pentair for not flagging up their preference for using Pentair GFCI's and with another post specifying the Pentair version, I immediately noticed it was a double pole GFCI unlike my single pole one (both old and new). Again, no Pentair install guide mentioned this.

I still question the energy efficiency between VS pumps and single/dual speed pumps as surely it depends on how the timer is programmed. IMO, a 1 HP pump used at the lower speed say 1500 RPM for 8 hours a day shouldn't use any more power than a VS pump programmed for 24 hours use at variable speeds. At any given speed, a VS pump has more losses converting AC to DC and again DC back to to variable frequency/voltage AC for a 3 phase pump.

I'd certainly be interested to see real studies on this.
Click to expand...

@mas985 is our resident pump expert. Perhaps he has some links to studies or some good info on that.
 
Mike,

I think you are missing the point... You do not have to run your pump 24/7, it is just something some of us like to do because we have a Saltwater Chlorine Generator. The point being, that even running my pump 24/7 I use less than $20 bucks of electricity a month.

Running only 8 hours a day, then that would be about $6 bucks a month.

A VS pump should reduce your electrical cost by about 75% or more.

Even running non-Pentair GFCI breakers, 'most' IntelliFlo pumps do not have GFCI issues. Only in a few cases do you need to install the Pentair GFCI breaker.

Thanks,

Jim R.
 
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Mike1000 said:
it is an intelliflo pump
Click to expand...

Mike1000 said:
I immediately noticed it was a double pole GFCI unlike my single pole one (both old and new).
Click to expand...
The IntelliFlo requires 230 volts, which is a 2 pole breaker.

If you are using a single pole, you have the wrong breaker.

I seriously doubt that you have a single pole breaker going to the IntelliFlo pump.

1676244617339-png.473061
 
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Mike1000 said:
In 2019 my old single speed 110 V AC pump started leaking and had to be replaced. I was 'persuaded' that the way to go was by replacing it with a variable speed Pentair pool pump that cost around $1,000 as they allegedly would pay for themselves in a few years by savings on electricity bills. 3 years on I've seen little difference in running costs and for the past year a lot of aggravation with the old GFCI tripping. So far its cost me over $1,000 to get a new GFCI & Housing fitted next to the pump and new cable to the main panel to meet current code but the tripping issue is still present. So is the problem the pump ?
Click to expand...
The issue is probably with the way you are running it. The lower the RPM, the lower the energy use. Many new VS pump owners run their pumps at a much higher RPM than is really necessary.

Mike1000 said:
Here lies the problem that I see as, variable speed pumps cost a lot more than a 110 volt (or 230 volt) simple induction motor pump as first the 110 volts AC has to be rectified to 110 DC which is then used to power a variable frequency inverter (drive) that supplies an induction motor with a variable frequency & voltage drive depending on the selected RPM by the user. At stop the frequency is 0 Hz and there is no voltage but both parameters are ramped up to give a pump RPM of around 1500 RPM for low speed lower energy use for most of the time and up to 3450 RPM for high speed when cleaning the pool.
Click to expand...
Yes VS pumps cost more than a single speed pump and it may take a while to pay it off but this is really a moot point. DOE regulations have halted the manufacture of most SS pump although you can still find some that are very small.

Pump DOE Regulations - Further Reading

A VS pump motor is over 92% efficient and that includes the drive electronics. The fact is that most inverters these days are very efficient and not much energy is lost. That 92% is mostly due to winding loss in the motor itself and not in the drive electronics. Compare that to an induction motor which is less than 60%-80% efficient depending on the THP of the motor (lower THP has lower efficiency). Note too that in a VFD, the voltage is not actually changed. Pulse width modulation is used to change the effective or average voltage over the modulation period. The voltage is switched on and off via IGBTs with different duty cycle to affect the average voltage. This makes the drive very efficient with little loss. About the only loss is the 0.7v drop in the rectifiers as a small gate offset in the IGBT. Less than 2v in 230v or less than 1% in efficiency loss.

Mike1000 said:
Thanks for replying, it is an intelliflo pump but the pump program has been roughly 4 hours from 8.00 till midday at 2500 RPM, then at 1500 RPM for 3 hours and then 3000RPM for 2 hours.
Click to expand...
There is your problem. Why are you running at such a high RPM? The 1500 RPM cycle is likely sufficient without the other cycles. If not, just increase the 1500 RPM run time. Ideally, you want to set the RPM to the lowest RPM possible and still meet the needs of your system. Skimming, SWGs, heaters all have minimum flow rates to operate properly but it is fairly easy to tell when this threshold has been met. SWGs and heaters will alarm when flow rates are too low and for skimmers, you want the water to run over the weir door and not around the sides. So I suspect you can reduce the energy consumption of your pool significantly if you just optimize the pump RPM.
 
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