Question about testing a well pump

[Qapla]

Here is the situation ...
An irrigation well with a 4" submersible pump was tripping the "overload" on the bottom of the controller. When I reset the overload, it would run and pump water. After a minute or two of running the pipe coming from the well would begin to "rattle" and even "shake", and the overload would kick out.

We tried jumping the overload and discovered that if the pump kept running the water the well was producing would drop to almost nothing.

Because of the overload button tripping, it was determined that the "run" side of the pump was bad and a new pump was ordered.

I pulled the pump from the well and found it had about 50' of 1 1/4" galvanized drop pipe. When putting the new pump back down we used 1 1/4" schedule 80 PVC drop pipe. The PVC comes threaded with bells and we did not want to cut the pipe at the well seal so we intended to use the 60' of drop pipe.

As I was sending the pump down it suddenly "came to rest" and stopped with about 10' of pipe sticking out of the well. We found the well had "collapsed" and a well company was called. They confirmed that the well was gone and a new one is going to be put in at a new location on the property. We will be using the new pump in the new well.

When I got home with the "old" pump I tested the pump for ohms. It is a "three wire" pump with red, yellow, black and green wires. The readings for the red/black, red/yellow, and yellow/black are all within tolerance. I would like to test the pump to see if the overload was tripping because the pump was getting "jammed" with debris from the collapsed well.

Here is my question - I wanted to know that if I remove the "liquid end" from the pump and connect the motor only on a bench could I safely run it for long enough to determine if the motor is really good and wont trip the overload or will the motor get to hot without being submerged?

 

[E/S]

Yes you can run just the motor on the bench to test it ( for a short period of time ).
But that will not give you the whole picture of the pumps condition. You really should run it submerged on a test bench to tell its condition.

E/S

 

[ThomasH]

If you put a u shape connection on the output of the pump, and drop it into a large trash can, you should be able to test it. You will have to make sure that the U section is held in place so that the pump doesn't spin.

 

[Qapla]

I guess I will need to do a "wet" test. It will be a few days before I will have the time to do any testing. Thanks for the replies.

 

[E/S]

Put a valve in the " U" pipe, that way you can load the pump to check amperage.

E/S

 

[vwnotrunning]

It would be beneficial to put a gauge before the valve to allow you to determine what head the pump can producre also.

 

[Tractor Seabee]

Beware, as you restrict the discharge line the amps go down. If you look at a pump performance curve you will see that the highest load is when the pump is at its full curve GPM/pressure capability. Your problem probably was the well colapse jambed the pump rotor and pushed the motor toward the locked rotor amps, hence tripping the overload.

Ron

 

[Qapla]

Thought I'd give an update.

Got the chance to do some bench testing today. The pump motor is toast The bearings were gone. Since it was so bad and I don't think I can save it, I took it apart and found there was water inside.

My guess is that when the well collapsed and the system was still active that the pump ran when there was not enough water and the pump overheated causing the seals to fail and the bearings to go. Then, because it was now able to "bind" this would be a good reason it would throw the overload.

It will be about 30 days before a new well is put in and the new pump goes down. At least we will have a functional irrigation system. But, I will not have a spare pump since the old one is gone. :construction: