About to drill well - Need Advice

[Pettrix]

About to drill a well in Northern AZ. The well depth will be around 350-400 feet deep with around 30GPM.

I have been given 2 options for the well pump:

Grundfos 1.5 HP 10GPM (10SQE 15-330) and the CU301 Controller - $3,800 installed
Goulds VFD 2.0 HP 13GPM (13GS20) and the AquaDrive Controller - $4,700 installed

The well drilling costs are around $6,800 (400' deep, casing, etc)

The house has not been built so the well is being put in to provide water for the job site, compaction, etc. So the well equipment will be sitting outside for a few months and the well pump will be run off of a generator.

 

[Valveman]

If the water level turns out to be at 300', that Grundfos SQE will only pump about 7 GPM. If the water level is any deeper than 300', that pump just won't cut it. I believe the 1.5 HP is the largest SQE they make, which is why that is what they offered.

The Goulds 13GS20 will deliver 14 GPM from 300', and will still pump 8 GPM from 400'. A Grundfos 16S20 will do the same, if you like Grundfos better, which I do because they have Stainless Steel impellers and a good drop in amps at low flow. The Goulds has plastic impellers and not as good an amp drop. The SQE has plastic composite impellers and spins at 10,700 rpm as compared to the normal 3450 rpm from the other two normal type pumps.

They are going to tell you that the 3 phase motor needed with the Goulds "Aquadrive" will be more efficient and save money because it can use smaller wire down hole. The difference in efficiency between the 3 phase motor and a normal single phase motor is not even worth mentioning. And you will be able to use smaller wire down hole with the 3 phase. But that is how they lock you into replacing that expensive and short lived VFD "Aquadrive" several times, because once you have a 3 phase motor, you must have the "Aquadrive" to convert your single phase house power to three phase to be able to run that motor. So that makes it expensive to pull the pump, replace the wire with larger wire, to be able to change to a standard single phase motor.

Constant pressure systems are a very good idea, but how you get that constant pressure is important. The variable speed systems like the SQE and Aquadrive use a $1200+ computer to vary the speed of the motor, while we can do the same thing with a simple and dependable CSV1A valve for maybe $200. Plus the CSV uses a standard single phase motor spinning at normal 3450 RPM, and doesn't have any of the electrical problems associated with variable speed drive systems.

Of course the CSV system will cost at least $1000 less than the variable speed systems and will last much longer, which is why they are not offering you the CSV system. They will even try to tell you the CSV is bad for pumps and anything they can say to get you stuck with a variable speed system, which I believe is a lot like the old story of the Tar Baby.

Either the 13GS20 or the 16S20 with a single phase motor will work with the CSV. The only concern with the CSV is that the water level in the well needs to be deeper than 135', which I would think it is, so as not to put too much pressure on the CSV.

You are wise to do your own research, because now you actually know more about it than the pump guy who is trying to sell you a variable speed system. If he really knew what he was doing and was trying to do the right thing for you, he would have priced you a system with a CSV to start with.

Oh and generators don't get along well with the harmonics created by a Variable Speed Drive (VFD).

 

[Sponsor]

 

[Texas Wellman]

The Grundfos SQ series plays very well with a generator and would be my #1 choice depending on the depth to the water. You don't have to use a variable speed controller with a SQ but I think that the CU301 can be added at any time later.
Is this an on-grid well or are you off-grid?

 

[Valveman]

The Grundfos SQ series plays very well with a generator and would be my #1 choice depending on the depth to the water. You don't have to use a variable speed controller with a SQ but I think that the CU301 can be added at any time later.
Is this an on-grid well or are you off-grid?

TW, I know the SQ works well on a generator, but does adding the CU301 and making it variable speed mess with the generator like other VFD's do?

 

[Texas Wellman]

That I don't know. What I think (I don't use VFD's) is that any SQ pump can be converted to a SQE by adding the CU301 box. Can anyone confirm?

I would just use a SQ pump matched to the conditions of the well and use a normal pressure switch. But, as you say, if the water level is very deep the SQ won't pump much water as the level drops.

TW, I know the SQ works well on a generator, but does adding the CU301 and making it variable speed mess with the generator like other VFD's do?

 

[Reach4]

That I don't know. What I think (I don't use VFD's) is that any SQ pump can be converted to a SQE by adding the CU301 box. Can anyone confirm?

I am pretty sure that is not the case. Different part numbers. Different prices. The SQE can be used as an SQ would, but the control box would not work with an SQ. It may be that the SQ is the same inside as an SQE, but has been somehow programmed or modified to ignore the controller signals. I don't know about that. It could be that some of the SQs failed their communications test, and were downgraded somehow. It would be interesting to weigh an SQ and a matching SQE with a very accurate scale. Grundfos shows the same dimensions and aprox shipping weight for SQ and SQE.

The SQ ramps up to 10,700 RPM every time it turns on until the pressure switch stops the incoming power.
I had a 10,000 RPM hard drive fail, and I put in a 5400 RPM hard drive to give up speed for reliability. The SQE with control box would seem to be able to keep the RPM down most of the time, but it adds complexity. A regular 60 Hz pump always goes less than 3600 RPM.

 

[Texas Wellman]

Well thanks internet cowboy but from my own personal experience the sq has just a long life as a regular 3450 rpm pump.

 

[Reach4]

Well thanks internet cowboy but from my own personal experience the sq has just a long life as a regular 3450 rpm pump.

Good to know. That 2.9 inch OD sure sounds like a really nice aspect.

But haven't those pumps only been out for about 20 years? They show SQFlex in 2002, but don't mention SQ and SQE in the http://www.grundfos.com/about-us/grundfos-milestones.html or http://www.grundfos.com/about-us/grundfos-milestones.html timeline.

PumpMD averages 21.4 years old for the pumps he replaces.

 

[Texas Wellman]

They used to be called a "Jet sub". They've been around AFAIK since the 1990's. We don't use many of course but the few we do use don't seem to have any more problems than the rest. Of course, all bets are off in a sandy or gritty well.

 

[Valveman]

From Grundfos' own engineering manual, specifically talking about the difference between an 1800 rpm turbine and a 3450 rpm sub, they say that "doubling the rpm of a pump will quadruple the wear rate".

And I would think adding the CU301 control and making it variable speed would still cause harmonic distortion to a generator from the pulse width modulaion created by varying the speed.

But I also do not know why anyone would use varible speed while using a generator, as you would want to fill a tank or use the water as quickly as possible so the generator could be shut off. With a variable speed you would not have ANY water unless the generator stayed running.

 

[Pettrix]

I was also offered an option of a FRANKLIN SubDrive20 QuickPak constant pressure pump. The controller is enclosed in a Nema3R rated enclosure and the system comes with a 5-year warranty on the pump, controller and motor. ($4,500)

Supposedly the Franklin system is a better designed system than the Grundfos.

 

[Valveman]

I was also offered an option of a FRANKLIN SubDrive20 QuickPak constant pressure pump. The controller is enclosed in a Nema3R rated enclosure and the system comes with a 5-year warranty on the pump, controller and motor. ($4,500)

Supposedly the Franklin system is a better designed system than the Grundfos.

That all depends on which "salesman" you are talking to. And I don't think that is the case. They may replace the controller for free a time or two in 5 years, but in 5 years and 1 day, you will be left holding the very expensive replacement bag.

 

[Pettrix]

I am more confused than ever on these well pump systems. I ask 10 people and I get 10 different responses.

One well driller refuses to even install a system with a CSV and said that due to the "backpressure" he won't warranty the pump. So if I get a CSV then I have a ZERO DAY warranty on the pump and system.

Back to the drawing board.

Are Danfoss controllers any good? What about Goulds pumps?

 

[Craigpump]

Last I knew, the Sub Drive controller had a 3 yr warranty, but VFD's are updated so often that possibly they offer 5 yrs now.

I am more confused than ever on these well pump systems. I ask 10 people and I get 10 different responses.

One well driller refuses to even install a system with a CSV and said that due to the "backpressure" he won't warranty the pump. So if I get a CSV then I have a ZERO DAY warranty on the pump and system.

Find another well driller.

I don't have many CSV's in service because very few consumers understand them and don't want to take the time to educate themselves, but the few I've installed have worked flawlessly.

 

[Pettrix]

Are Goulds pumps made in the USA?

Goulds also makes a controller called AquaVar Solo3.

The one driller is giving me a 5-year parts and labor warranty on the above system.

 

[Craigpump]

I install pumps and do service for a living, not a hobby. Go with a time tested and proven system consisting of a dumb pump, a CSV and a tank with a pressure switch. Why? They are so easily serviced by just about anyone. Pressure switch goes bad on Sunday, your local pump guy has 3-4 on his truck. But he may not have a transducer. Bad control box, same thing, but a VFD controller? I doubt it.

 

[ThirdGenPump]

Are Goulds pumps made in the USA?

Goulds also makes a controller called AquaVar Solo3.

The one driller is giving me a 5-year parts and labor warranty on the above system.

Goulds pumps are made in the US. The motors are controllers are made in China.

Solo 3AS maybe. The current generation of controllers are AquaVar Solo2's The 1AS15 can drive any single phase motor 1.5 HP and under. The 3AS20 is for 2HP and under 3 Phase Motors. 3AS30 for 3HP and under. 3AS50 for 5HP and under.

Typically on a new install you'd use a 3AS controller and a 3 phase motor. The 1AS's get used to retrofit an existing system. Goulds does keep pushing the 1AS's as a package so sometimes that's a better 'deal'

I actively avoid installing drives, they are a pain in the ass and fail expectantly. I stock a transducer on each van now but I do not stock drives, no way I'm getting stuck with them, they keep changing them as they work the bugs out. Maybe some day drives will be the way of the future manufactures keep claiming them to be, as it stands now the best drive is whatever manufacturers drive is the most recent, and they are all junk.

 

[Valveman]

One well driller refuses to even install a system with a CSV and said that due to the "backpressure" he won't warranty the pump. So if I get a CSV then I have a ZERO DAY warranty on the pump and system.

That is the only sign you need to know that well driller has no clue what he is doing. The backpressure from a CSV actually reduces the amp draw and makes the pumps work easier. And he has no say on warranty. All pump companies will honor their standard warranty no matter how you control the pump. Read the standard warranty from any pump company and you will see that it does not "disallow" warranty for the use of a CSV, Dole Valve, or any other type control. That would be rather stupid on their part, as the CSV actually makes pumps last longer, not the other way around.

But that installer will try to sell you a VFD type system as he makes a LOT more money that way and gets to come back and charge you for repairs on a regular basis. Yes you will get 10 different answers as many will just try to sell you what lines their pockets, not what is best for you. You are wise to research and make your own decisions. You are the only one looking out for your best interest.

I guarantee the CSV to work as advertised or you can send it back for a full refund., and have never got one back in almost 24 years we have been doing this. See if they will offer you the same deal with a VFD?

 

[Valveman]

The one driller is giving me a 5-year parts and labor warranty on the above system.

Franklin started out with a 5 year warranty on their VFD's, then quickly changed it to 3 years. But no matter the warranty time, they know they may have to warranty the controller a time or two in 5 years, but the 6th year they get to make up for it by charging you for new equipment.

Don't get me wrong. There are many benefits to a constant pressure system. I am pleased that EVERY pump company sees that and is trying to offer a solution to some of the problems of the old traditional systems. But the fact that EVERY pump company is pushing VFD's, means that is how they are making the big money, which is just the opposite of being a good thing for you.

 

[Valveman]

Maybe some day drives will be the way of the future manufactures keep claiming them to be, as it stands now the best drive is whatever manufacturers drive is the most recent, and they are all junk.

Thanks ThirdGen and Craigpump. Many companies started telling me the newest version of their VFD had all the bugs worked out in about 1990. Yet every 12-18 months they come up with a new BandAid for one of the many problems associated with VFD's. Having studied electrical engineering, I understand the problems associated with VFD's are laws of physics that mother nature will not let anyone change, so those problems can never really be solved. I started with VFD's in the late 80's and like to say I am an expert on VFD's, which is why I would never use one on a pumping application. I have VFD's on some of my plastic injection machines, a heat pump, and even a treadmill, as on some things they are worth all the trouble. But that is not the case for normal pumping applications.