Submersible pump failure in cistern

[Valveman]

I think this is why Franklin went with the new tri-seal so little amount of backpressure is being applied to the thrust bearing. I am interested in seeing how they hold up in the field.

It doesn't matter how much backpressure is on the thrust bearing as long as it has the proper cooling flow going past it. A little bit of backpressure will destroy a thrust bearing as quickly as a lot of backpressure if there isn't enough flow past the motor to keep it cool. This is why a motor shroud is important.

 

[PumpMd]

Proper Cooling for the windings, not the thrust bearing or I would see Franklin stating the thrust bearing. Besides, do see evidence on the outside of that motor that shows it wasn't getting the proper cooling?

 

[Sponsor]

 

[Valveman]

Proper Cooling for the windings, not the thrust bearing or I would see Franklin stating the thrust bearing. Besides, do see evidence on the outside of that motor that shows it wasn't getting the proper cooling?

Franklin doesn't state winding or thrust bearing, but it is both. It is just as important to keep the thrust bearing cool as it is the winding.

 

[PumpMd]

You are correct, it does say for the motor but I still stand firm that the Stainless Steel Shell, would let me know if there was a cooling problem.

 

[Valveman]

You are correct, it does say for the motor but I still stand firm that the Stainless Steel Shell, would let me know if there was a cooling problem.

So would a thrust bearing if the shaft stickup was low.

 

[PumpMd]

The motor didn't show me the sign on the outside, what makes you think the motor fluid got hot enough to do damage to the thrust bearing?

This well casing was the Rare 4" in our area

 

[Valveman]

Today I came across another pump system that works only a sprinkler system in a neighborhood so it turns off/on few times and has the bearing failing because sometimes it runs fine and others times it will have locked rotor amps.

 

[PumpMd]

So you are saying this is the reason why I don't see this problem when cycling the pump because the motor fluid has time to cool but if your going to run continuous for long periods of time, you are going to need a flow sleeve for the motor fluid?

 

[Valveman]

You were the one who said the bearing failed. I was just quoting what you said. But when cycling on and off a motor doesn't have time for the heat to be transferred to the housing, so the internal heat cannot dissipate and just builds up a little more with every cycle. The motor doesn't really run long enough for a shroud to be of much use. Cycling is a problem the shroud cannot help.

When the pump/motor is running continuously the heat is dissipated to the case over time and the flow past the motor wicks it away, so flow past the motor is important as when using a shroud.

 

[PumpMd]

You do know Franklin says "flow inducer sleeve is not required in water up to 86F (30C) for motors through 2hp"?

 

[Valveman]

You do know Franklin says "flow inducer sleeve is not required in water up to 86F (30C) for motors through 2hp"?

Yeah and do you know why? It is because they have made those motors so short they say the water still circulate enough, even around the bottom of the motor. But Franklin made the motors shorter AND says you don't need a shroud, BECAUSE they like selling more motors.

 

[PumpMd]

The problem was rock pebbles in every stage of the pump where it was very hard to turn. I started the motor 25 times with no problems. Franklin is correct but we have tested 3hp and 5hp with no problems.

 

[Reach4]

The problem was rock pebbles in every stage of the pump where it was very hard to turn. I started the motor 25 times with no problems. Franklin is correct but we have tested 3hp and 5hp with no problems.

With a shroud extended down a bit, would the pebbles have got sucked in?

Anyway, you can agree that a shroud has some advantage when your flow is reduced due to back-pressure such as from a CSV. It can help for a top-feeding well to flow water by the motor, and it could serve as a sand/pebble retarder in some cases.

 

[Valveman]

With a shroud extended down a bit, would the pebbles have got sucked in?

Anyway, you can agree that a shroud has some advantage when your flow is reduced due to back-pressure such as from a CSV. It can help for a top-feeding well to flow water by the motor, and it could serve as a sand/pebble retarder in some cases.

An extended shroud would certainly have helped keep the pebbles out of the pump. A shroud also helps with top feeding wells, low flow conditions, and other things. And anything that helps a pump is a bad situation is even better for pumps that are not in bad situations.

 

[PumpMd]

With a shroud extended down a bit, would the pebbles have got sucked in?

Anyway, you can agree that a shroud has some advantage when your flow is reduced due to back-pressure such as from a CSV. It can help for a top-feeding well to flow water by the motor, and it could serve as a sand/pebble retarder in some cases.

That question would need to be answered by Craigpump because we don't use them(can't use them on most of our wells either) and he is the one that said "It will keep sand out of the pump".

Even on CSV's, I have never seen a problem with cooling of the motor. We have talked some about the pump end failures.

 

[Reach4]

That question would need to be answered by Craigpump because we don't use them(can't use them on most of our wells either) and he is the one that said "It will keep sand out of the pump".

Just thinking it through, it seems that pebbles would have a hard time climbing up a shroud that extended several inches below the pump. The water velocity would be pretty low at that point. This aspect of a shroud keeping pebbles out would seem to be particularly useful on uncased wells.

 

[PumpMd]

An extended shroud would certainly have helped keep the pebbles out of the pump. A shroud also helps with top feeding wells, low flow conditions, and other things. And anything that helps a pump is a bad situation is even better for pumps that are not in bad situations.

Why was the pump ever in that situation to start with or did something happen to the well?

 

[Valveman]

Why was the pump ever in that situation to start with or did something happen to the well?

Uh, are we still talking about the pump you posted pictures of that had the rocks in it? If so, how would I know?

 

[Craigpump]

Yes, a long flow inducer will definitely keep heavier sand and pebbles out of the pump.

 

[PumpMd]

Uh, are we still talking about the pump you posted pictures of that had the rocks in it? If so, how would I know?

Didn't you drill wells? This wasn't are pump set, it was probably from the well driller but it was set 20ft off bottom(really about 15-16' including pitless and pump.