Selection of reliability of deep pump

[Alternety]

I am having another exercise with the well from Hell. My third Lorentz is dead. It sits at 550' (650' to bottom).

Supplier thought it was the controller. I bought another controller - no. So I need another new pump. I have been without water for about 1.5 month. The water is free of sand or other junk. Not corrosive.

While working with a vendor for the problem, they suggested a Grundfos 6SQF-3 instead of another Lorentz. Either would provide acceptable flow. Including the pump still in the well, I now have 3 dead Lorentz pumps from about 15 total years of use.

My question. Which pump is the most reliable and long lived. Other possibilities would also be considered. I favor the Archimedes pump approach. Less power consumed. Should last a long time.

I looked at the documentation of the Grundfos. It has a huge amount of parts in the pump. Lorentz, not so much. I have seen some comments about problems with Grundfos in some versions.

I am hoping there are people out there that can share results with the pumps.

 

[Reach4]

I am having another exercise with the well from Hell. My third Lorentz is dead. It sits at 550' (650' to bottom).

I presume that is solar powered, or some other non-regulated powered system, right?

 

[Sponsor]

 

[Alternety]

No. 120 VAC

 

[Reach4]

No. 120 VAC

No 240 vac available? If that is the motivation for getting these specialized pumps, I would use transformer in a boost configuration to give 240 VAC. Then a world of reasonably priced common pumps becomes available. Maybe 1.5 or 2 hp 7 gpm.

How many amps of 120 vac are available?

 

[Alternety]

That was rather brief. I had to go away for a bit.

You beat me to it.

The Lorentz uses a controller that needs DC and generates 3 phase power to the pump. The controller is in the house and I feed it DC from a line powered power supply I built. The controller has very limited information and no control really.

Grundfos will take a wide range of AC and DC. It appears that AC or DC is fed directly to the pump from the controller and it uses whatever you have. I would just use 120 VAC. I lack some details hidden behind the No Civilians wall. Their controller is much smarter than the Lorentz. Does diagnosis and monitoring. There are also built in control/monitor functions in the pump.

Overall I like what I see in the Grundfos much better than the Lorentz. I guess my specific need is getting feedback on the Grundfos reliability.

There is no accessible 240. One reason I did not provide that is the desire to use pumps with lower power demands. Both of the ones I have discussed do that. I want to be able to power them from a generator if I need to.

Both pumps will be running at 550'. They are both helical pumps. They use less power (< 1 KW). And they should last longer than centrifugal pumps. You do not (I think) see a lot of helical pumps to choose from.

 

[Valveman]

Helical pumps are a really old design. In the sixties there was one called the Peerless Wiggletale. It would keep building pressure as long as the motor would spin it. When a pressure switch failed to open they would send an old galvanized tank shooting through the roof like a rocket. The will work at low RPM's, which makes them more efficient when using solar. The problem was always how to balance and hold a helical shaft centered. The pig tale type shaft will slap around and knock the top bearing out of the motor. While they work well at low RPM's. high RPM's will greatly shorten the life. A regular centrifugal impeller type pump will last much longer/

Like Reach says you can use a boost transformer to up the 115V to 240V. A soft start on any submersible motor can be had by simply using the longest length of the smallest wire possible for the size pump you have. The long length of small wire makes a reduced voltage starter that reduces the starting torque similar to one of those expensive soft start panels.

Also many of the Grundfos SQ pumps work on 115V. They have built in electronics that give a 5 second soft start feature. Although the SQ spins at 10,700 instead of just 3450 RPM it still has a centrifugal impeller and will last much longer that a helical shaft pump.

 

[Reach4]

Both pumps will be running at 550'. They are both helical pumps. They use less power (< 1 KW). And they should last longer than centrifugal pumps. You do not (I think) see a lot of helical pumps to choose from.

I did not realize those pumps were so power-efficient. You can power that pump with a single EU1000i? What size wires do you have to the pump?

 

[Alternety]

Guys, I appreciate your looking at this. But all of you are going somewhere else.

There is only one question. Are Grundfos

6 SQF-3 SUBMERSIBLE PUMP - HELICAL ROTOR, 3"

relaible?

 

[Valveman]

Guys, I appreciate your looking at this. But all of you are going somewhere else.

There is only one question. Are Grundfos

6 SQF-3 SUBMERSIBLE PUMP - HELICAL ROTOR, 3"

relaible?

Sure, until they quit. LOL! As mentioned I do not believe the helical shaft is nearly as long lasting as a regular impeller like in the straight SQ or SP pumps.

 

[VAWellDriller]

I've used a grunfos SQF for over 10 years sampling and purgingow yielding observationservation wells for our state DEQ. Only used the one pump but NEVER had a failure....and it pumps nasty stagnant water from rusty steel caused wells.....some salt water some really irony water some really high manganese.....hardly ever clean good water. We set it up with solar panels...it has run dry protection....and use a 120volt generator when necessary if they need samples when sun isn't out. You will need to use very large wire to set it that deep and run 120 volts...probably #6 but I'd have to look.

 

[Valveman]

Good to know. But sampling and purging is still not 24/7 for years at a time. When powered by solar or a generator they don't usually run long periods of time like when tied to the grid. The old Peerless wiggle tales would last pretty good as well until they knocked the top bearing out of the motor. Rarely was there a pump end failure.

 

[VAWellDriller]

Good to know. But sampling and purging is still not 24/7 for years at a time. When powered by solar or a generator they don't usually run long periods of time like when tied to the grid. The old Peerless wiggle tales would last pretty good as well until they knocked the top bearing out of the motor. Rarely was there a pump end failure.

As I used it...the pump would get a lot of run time. We set it up and turn it on....it runs when the sun shines for weeks or months at a time then gets moved to another well. (Usually anywhere from 7 to 12 hours a day). It gets a lot more use than a pump would at somebody's house.

 

[Valveman]

When the sun shines does it run at full speed? Or is it loping along at lower speed most of the time? I can see the helical shaft lasting longer at low speed.