Start Capacitor for Failing Pump

[HumanJHawkins]

I have a 350 ft. well with a 17 year old 2HP pump. Recently, the overload has intermittently tripped instead of the pump starting. I have only noticed failure on startup. If it happens to run, it always fills the tank. When it fails, I can shut off the breaker, wait a few seconds, turn the breaker back on and then reset the overload for another fair shot at getting it to start. So far, it has usually started on the second try. Once it took three tries.

I've tested the above ground equipment and it all tested good. The start and run capacitors were right on spec. I've also tested the resistance of the windings and it all appears to be within spec. The resistance to ground is a bit low at 1M ohms, but I am told that in an installed well it is considered OK as long as it is above 500K.

So, my theory is that wear in the pump has lead to increased friction that make starting more difficult.

I know the pump will need to be replaced soon regardless, and I know one should not use a different value for the run capacitor. But I'm wondering if it is likely that I can buy a few more months by doing something with the start capacitor. The spec calls for a 105-126MFD. Would moving to a 124-149MFD, or 189-227MDF give it a bigger start kick and maybe make it start more reliably until I can get the thing properly replaced? Or would that just make it overload more quickly?

Thanks in advance for any tips.

 

[Valveman]

You can do that. A little larger start cap can sometimes get a locked up pump to start. But the extra spark isn't good for a motor that has already had too many starting sparks. 17 years is almost 3 times the average motor life. Don't expect that kind of life from a new pump, as they are not made as good anymore. If that pump had been controlled by a Cycle Stop Valve it would still be like new and have at least another 17 years left in it.

 

[Sponsor]

 

[Fitter30]

Has the start cap been tested for now much capacitance it has? Wouldn't go over 10% increase in cap 124-149 uf

 

[Valveman]

Could also be the starting relay. It will trip the overloads if the relay fails to disconnect the start cap in a second or so.

 

[HumanJHawkins]

Great info all. Will let the group know how it turns out. To answer some of the questions, the capacitors test to right in the middle of their range with a Fluke meter. Will see if a 10% larger start cap decreases the percent of start failures.

I haven't pulled and tested the relay, but it is pretty obvious when the pump actually comes on. It isn't coming on at all when it fails, so I don't believe it could be the relay sticking on to trip the overload.

I'm going to add a cycle stop valve either way. I actually asked about that sort of thing when I had it put in years ago, but apparently didn't ask the right person or maybe I just didn't know how to ask the question. That sounds like a heck of an improvement for my situation, and I'm bummed that I didn't stumble onto it earlier. Thanks for the suggestion.

 

[Valveman]

Most likely a motor problem. After a motor has cycled that many times the water inside them looks like dark coffee with a lot of grinds.

 

[HumanJHawkins]

For anyone who was following this, a slightly larger start capacitor has it working consistently for now. I know this isn't a proper fix, but hopefully it will buy me a few months or more.

I took the opportunity to redesign the plumbing. @valveman, I'm planning to install a CSV tomorrow, along with several other improvements. The new plumbing will be there for the next pump, whenever it is needed.

Thanks for the help all.