Yeah, load should be highest at whatever point of the Pressure-Volume curve where it's doing the most work (pumping the most water). Even cavitation lowers the load on the motor
Nope.
You have the right idea just need to think about it a little different. The pump minder will shut off power to the pump on low water and therefore low amps because less water is being moved and the motor is doing less work.
Plugged discharge on a centrifugal pump brings the load down. It's like hearing your vacuum cleaner speed up when you put your hand over the end of the hose.. No work is being done because there is no volume of flow
How do you get to that conclusion? This is literally a classic case that gets me onsite. Make the decision if a pump comes out. You are making the wrong call if you don't properly vet the start circuit. If you don't want to test the relay, just replace it and start there. There have been several cases where the start wire is damaged, not allowing proper amperage, thus the pump can't start, yet meter checks show otherwise.It appears I was mistaken due a severe case of rectal cranial inversion.
The “load” light on the PumpTec controller is flashing, which indicates an overload situation. Steady on indicates an underload, or low water condition. I took 5 seconds to read the manual and undeceive myself about what is going on. So much for relying on my memory.
At this point with all the troubleshooting I’ve done, it’s looking very likely that the actual pump is damaged.
nailed it!
It's an extremely unreliable method.
Again, if the relay is failing to open after the start, you will see high amps. If you want another test, insert your Vmeter on the red and yellow leads right on the well head and light it briefly. If the volts approach 300, the motor is turning. That is your back EMF talking to you. Do not run this test more than 2-3sec. If it' staying engaged, you risk exploding the capacitor.
Yeah the load is because you are accelerating the water (Making it go spinney) If no water is coming in, then all the water in the volute is already spinning
Most starters are built mostly the same thus why I indicated the test at the well head where there is usually a pigtail. But, if you have condemned the pump, is what it is. Hopefully you find the culprit. Report back. Pretty rare that that a pump is stuck unless sand logged.
I stand corrected and I knew that. It is the PSI that can go high.
Nope, seems like you have most covered by now. Personally, I generally find the real culprit just for piece of mind such as removing pump motor when out and running it. A cracked rotor can do this. All winding tests are normal, pump is free, yet pulls high amps and does not turn at the right speed.
Even the PSI can roll off from cavitation or impeller stall. They should generally move a little water to test max PSI. We tank test down to like 1GPM and compare to spec as a good measure of impeller health. As they wear out, the impeller stages have a lot of slip and they struggle. A really quick tech note is to observe how fast a pump fills a pressure tank in relation to pressure and volume. I've condemned them before because you can clearly see the struggle.
There are some centrifugal that have a "Hooked Performance Curve" meaning that maximum PSI occurs at something above zero flow. I am told that when in the right application they can be very efficient. The problem is when there are multiple pumps connected to a common discharge manifold. Being that they start at zero flow, they aren't making enough pressure to overcome the pressure in the manifold.
