Aquavar spd vertical pump

my pump is about three years old, in a residential location. the motor of the pump has gotten louder and louder and I am not sure why. it has been stressed a couple times because the #%$@*^% who put it in made some mistakes (put wrong kind of ball valve in and put transducer in upside down), so there were occasions when the motor ran a lot. I also know our water has a lot of sediment in it and I wonder if that could be a problem? I've researched and it does not look like I can do anything like put some oil somewhere or hit a grease nipple--it is a sealed unit. I don't know if this is a bearing issue--it sounds like it--and I've had plenty of cars where bearings made noise but held up a long time. Any advice or ideas would be greatly appreciated. P.S. The pump generally runs properly, on and off, good pressure, etc.

The variable speed pumps generally do not hold up very long. I would start shopping for a replacement pump which is not a VFD.

That would be an Aquavar Variable speed controller, which is also known as a VFD for Variable Frequency Drive, or VSD for Variable Speed Drive, “Freak” drive for short, or it can also be called other names.

Power from a VFD causes Harmonics, voltage spikes 4X the supply voltage, and bearing currents also known as EDM currents that cause fluting of ball bearing races and pits in the balls themselves. This actually happens worse when the bearings are lightly loaded. Without much of a load the balls in the bearings don’t touch the races. The balls just spin in the lubricating grease, basically insulated from the races, which prevents any grounding. The EDM currents from the VFD create a little “lightning storm” when the bearing is spinning. The “lightning” discharges across the grease insulation and causes Electrical Discharge Machining or EDM in the bearings.

Pump manufacturers know about this and actually use it to plan the amount of time they want your pump to last. You should just be happy to replace your pump every 3 to 4 years. If you had a regular pump, running on standard power, it would probably last 30 years.

The quote I have heard several times is this. “Pump companies cannot stay in business making pumps that last 30 years.” They have engineered their pumps to last no more than an average of 5 years. They use cheaper, non-grease-able, sealed bearings. They shorten the motor length to make it run close to a critically hot temperature, and do other things to make the pump/motor fit within their time limit for planned obsolescence.

On larger motors they are now using brushes to ground the rotor in the motor, and insulated bearing races. Insulated races (plastic) are not as strong as standard steel bearings, and grounding brushes wear and therefore need regular maintenance.

However, some people have learned how to solve these problems and still get water delivered at a constant pressure. Controls like the Cycle Stop Valve can make a cheaply built pump that was designed to last only 5 years actually last 15 or 20. By simply eliminating the repetitive on/off cycling, and reducing the amp draw of the motor when using small flow rates, the CSV makes the motor run cooler and last longer than designed. The CSV does this while delivering constant pressure water, the same as a VFD. However, the CSV is a simple mechanical valve that does not distort the power to the motor, cause voltage spikes to the windings, electrical fluting of the ball bearings, or many other problems associated with VFD’s.

Some pump manufacturers are now designing the VFD to fit inside the motor. This way you have no way to circumvent their planned obsolescence by using a CSV.

In your case being able to grease the bearings would not help. It is the EDM currents that have destroyed your bearings, not a lack of grease. The worse the bearings get, the louder the noise, until someday soon it won’t make ANY noise, because the bearings are locked down.

VFD’s also cause a high-pitched whistling noise from the motor. This “whistling” is probably at about 4KHz, as that is the standard carrier frequency used with most VFD’s. You can reduce the “whistling” by changing the carrier frequency of the VFD. But not running the carrier frequency at its optimal range can cause other side effects.

I am sure someone talked you into the VFD by saying it would save energy and the soft starts will make the pump last longer. These are the lies they use to con people into purchasing a VFD, which is a “Cash Cow” for the manufacturers, and consequently a real “money pit” for the pump users. They have even conned Utility Companies and Government agencies like the DOE into offering incentives or tax breaks for installing VFD’s, because they supposedly save so much energy.

VFD’s do not save energy or make pumps last longer. There are several states that are now mandating Variable Speed Pumps to be used for swimming pools as well. VFD’s are used to make you think energy is being saved, so you won’t mind paying much higher prices for pumps, and won’t mind replacing them every couple of years, instead of having a pump that would last 30 years as it should.

Since I am already on my soapbox, let me say this. VFD’s do not save energy. Adding Ethanol to gas is a really bad idea. The government cannot spend us into prosperity with “Stimulus Money”, or manage our health care any better than they manage a freight delivery service (Post Office). Big government is not out to help us, but control us to line their pockets. If we don’t educate ourselves on these and other subjects, the fall of Rome will seem trivial next to the demise of our own country.

I’ll bet you never thought the little water pump for your house or swimming pool could be part of the Global Warming Conspiracy, but it is.

Fluted bearing race.

Valveman, you rock! Although I would not frame my comments about government quit as you do, I don't have any doubt that companies, usually through lobbyists, influence commerce to their benefit. I will tell you a little story which you will probably find a little funny if not certainly ironic. For several years I was a high level consultant to a certain company that makes a certain VFD pump and, of course, I personally knew the President of that company. I called her and asked if I could talk to an engineer who could help me choose the best pump for my unique needs in the dream house we were building (I had some elevation to consider and I wanted to place 3 remote fire hydrants around the house and we planned to run 2" lines directly to each hydrant). A very nice engineer called, got all the specs, ran the numbers (impressive charts!) and recommended the pump we got. I will say that when I opened one of the hydrants, using 1 1/2" fire hose and nozzle, and threw a steady stream of water about 75 yards, I knew I had purchased the right pump. Funny story? Since we live in Southern California, I still have a deep commitment to defending my house when the next big fire rolls through which almost makes me think about buying the same pump and keeping the controller. On the other hand, I would feel a lot better if I had a pump that would last 20 years, but I need a pump that can push a bunch of water out when I need it. The idea of a pump ramping up its speed to match the increasing need makes sense but not if the bearings could seize just when I need it most. How would a CSV affect my need to feed a fire hydrant? Thanks for you time (and education).

dschag said:

Although I would not frame my comments about government quit as you do, I don't have any doubt that companies, usually through lobbyists, influence commerce to their benefit.

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I have never had any doubts that companies market the products that make them the most money. I do the same thing. I also know the most profitable and popular products are rarely best for the consumer or end-user. One of our government’s only jobs should be to help protect us from false advertising, corrupt business practices, and even dangerous products.

Things like adding 10% Ethanol to our fuel causing a 10% reduction in gas mileage are well known and proven. Yet it is still mandated by our government, apparently because they don’t understand that 10 minus 10 equal ZERO benefit. If you add in the additional cost and damages Ethanol does to our engines, 10 minus 10 actually equals about negative 20 in our wallets.

Mandating VFD’s on pool pumps and water supply pumps to “save energy” is not as easily calculated, making it is easier to be deceived. As you said “The idea of a pump ramping up its speed to match the increasing need makes sense”. So it should also make sense that ramping down the pumps speed to match a decreasing need should use less energy, right? Wrong! The amount of energy used per gallon of water produced can increase by as much as 5 to 10 times when reducing the pumps speed with a VFD.

The confusing part of this subject is that the amount of energy used DOES reduce as the speed of the pump is reduced. But the reduction in energy needed to spin the pump and motor is not linear to the reduction of the flow rate. Seeing the amps drop on an amp meter makes it easy to con people into believing VFD’s save energy. Diversion is the oldest trick in the book. “Pay close attention to how much the AMPMETER is dropping.” The flow meter drops faster than the amp meter, which means the amount of energy used per gallon is increasing dramatically. But they keep your attention diverted to the amp meter and away from the flow meter so you don’t figure out the trick.

Did you read recently how the buildings in DC that where built to “Green Standards” are documenting considerably more energy use compared to standard construction buildings? I have no doubt false assumptions about VFD’s are a big part of that problem. Our government is eager to make it look like they are helping us, but “they can’t make a silk purse from a sow’s ear”.

I expect to see aggressive marketing and even some hype from companies eager to sell products. I do my research, make my own decisions, and live with the consequences. I have no problems with companies selling good products on a fair and level playing field. I do have problems with governments mandating that I purchase certain products. I also have a big problem with government giving incentives for us to purchase one product over another, when they have no idea what they are doing. When politics are the driver, practical engineering goes out the window, and that cost all of us.

I shouldn’t have gotten political. But if my government is mandating that everyone purchase a silk purse, they should at least have the intelligence not to make us purchase those made from sow’s ears.

dschag said:

I will say that when I opened one of the hydrants, using 1 1/2" fire hose and nozzle, and threw a steady stream of water about 75 yards, I knew I had purchased the right pump.

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Unless they have made another recent change I don’t know about, the Aquavar controller is not physically attached to the pump. It is the pump that is throwing a steady stream 75’, not the controller. There are several other ways to control a pump like that without using a VFD. You would just need a single phase motor on the pump instead of a three phase motor to be able to utilize a different type of control. The three phase motor locks you into needing the VFD and dealing with all the problems that come with.

dschag said:

How would a CSV affect my need to feed a fire hydrant?

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The Cycle Stop Valve is another way to control the same pump. With a CSV you would still be able to use 1, 2, or 3 of those big 1 ½” fire hoses and nozzles, as well as supply a shower or bathroom faucet by itself. And it would still throw water 75’, as long as the pump is large enough to do that. The CSV just lets the pump spin at full speed, using regular “un-distorted” power. The valve part of the CSV just holds back the pump when you only need to run a bathroom faucet or run just 1 of 3 fire hoses. But it will open instantly if you need more water and let you run all 3 fire hoses if you want. Even though the pump always spins at full speed, the amps or energy used is reduced when a valve restricts the flow, the same as it does when decreasing the speed of the motor. That fact is counter intuitive, but is just the natural way a centrifugal pump works.

Intuitively you would think reducing the speed of a pump would save energy, and restricting a pump with a valve would use more energy. This subject is so confusing because to understand it, you have to accept TWO counter intuitive, yet absolutely true properties of the function of a centrifugal pump.

ONE; Reducing a pumps speed with a VFD increases energy use per gallon produced.
TWO; Restricting the flow of a pump with a valve decreases the amp draw of the motor.

Once you understand these counter intuitive properties you will realize that a VFD is just trying to trick a pump into doing something pumps already do naturally. You don’t have to reduce the speed of the pump and live with all the problems of a VFD. Amps or energy used decreases naturally when a valve restricts the flow rate. So a CSV gives you exactly the same performance as a VFD, just without all the negative side effects.

dschag said:

I need a pump that can push a bunch of water out when I need it…….but not if the bearings could seize just when I need it most.

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If you set yourself up for problems, Murphy’s Law says they will always happen at the very worst time. The simpler you make the controls and the less electronics you have in the system, the more likely water is to come out the faucets when really needed.

Or....perhaps maybe the motor is typical of the cheap china syndrome (CCS) that seems to plague many of the motors we are receiving today and the bearings would have went out regardless of being a VFD or not.

Since it is an above ground pump/motor can you simply replace the motor on the unit? What is the horsepower and model of the pump/motor?

That Aquavar is a Goulds brand. Are they using those cheap motors as well? Even good bearings won't last with a VFD, but cheap bearings will last even shorter periods of time.

It may be a goulds brand but it's made by ABB IIRC.

I don't know about the type of pump he is talking about as I'm not familiar with that particular one but all the jet pumps, regardless of who makes the pump, use the old AO Smith (now Regal) motor that was made here, then Mexico, then China. I have started looking around for a replacement motor like Baldor etc. that is NOT made in china. If you have a Sta-Rite you're screwed as it is a special motor and only Regal (old AO Smith) makes it.

Thanks guys. I've determined that the motor is a Baldor, 5hp, model vm3613t. I talked to Baldor and they say the bearings should be greased at least every 22 months and I'd say mine has not had any maintenance in 48 months, so I will give the greasing a try. Any tips on greasing one of these motors? It sounds like there is one input hole and one output, for excessive grease. Any tips appreciated.

dschag said:

I talked to Baldor and they say the bearings should be greased at least every 22 months

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Wonder where that 22 month number came from? I would also assume that motor has sealed bearings, and greasing would do no good?

If they are grease-able bearings, over greasing is not a good thing. Just a shot or two per bearing is all you need.

There should be a grease cert for bearings in both ends of the motor. Usually these are just plugged and you have to add your own grease cert. But I have never seen a place for the extra grease to come out.