Pump Ran Dry Now Motor Won't Start

[RandyM1911]

Hi, I'm new to the forum and looking forward to learning more about taking care of my pool and equipment here.

I was away for a few days and when I returned the water level in the pump was below the intake line and the breaker for the pump motor was tripped. I didn't notice that until I flipped the red lever on the timer to start the pump and nothing. A family member used the pool while I was away and made adjustments to some valves, possibly reducing the intake flow too much for the pump to catch prime when the timer kicked on automatically the next day.

I reset the breaker and hit the switch again and heard a loud hum but the pump didn't start and after a few seconds the breaker tripped again. So I did some online research and pulled the motor to check the start capacitor which was clearly blown as it had leaked plastic goo out of its guts. I checked the motor and it seemed to spin ok although there is some bearing noise. I removed the diffuser and found some thin plastic debis between it and the impeller which must have been caused by the heat of the pump running dry.

At any rate, I cleaned up the plastic residue and replaced the capacitor but the same problem persists. Loud hum and motor won't start. With power applied (if I'm quick) I can start the motor spinning by hand and it will catch and run but it will not start on it's own after being shut off.

So here's my question: What specific parts are damaged when a pump runs dry until it "seizes" or stops spinning due to heat build up. Is it possible that even though I can spin and start the motor by hand the internal shaft seals are heat damaged and causing enough excess friction (or sticktion) that the motor starter capacitor can't overcome it? Even though I can start the motor by hand? Any suggestions for further troubleshooting and suspect parts identification would be sincerely appreciated.

Motor is a 2 HP Hayward Superpump, Pump is Hayward SP2615X20. Put into service in July 2007.

Thanks!

Randy

[PoolDoc]

I'll ask Mark or Al to take a look.

[RandyM1911]

Thanks, I may have answered my own question by digging a little deeper into the assembly.

It appears that the shaft seals failed and water got through them and into the shaft bearing near the wet end. Not sure what other damage may be present or if I can just have the bearings replaced and get new shaft seals and O-rings. Biggest problem is time without the pool filtering/generating chlorine and what the consequences of that will be...

[mas985]

Did you replace the seal? That can cause extra friction and prevent the motor from starting. Also, there should be no bearings noise either so if you feel or hear anything, that could be causing extra load on the motor so it won't start.

[RandyM1911]

Thanks for the reply but it looks to be to far gone. I took the whole thing apart and the front bearing is shot. There's a lot of rust and corrosion at the front end. It looks like the pump must have been leaking into the motor for some time based on the amount of corrosion. Looks like I'm into a new unit.

[aylad]

That happened to me at the end of last year, but I was able to just replace the motor and seals but keep the rest of the pump.. Saved me about $350 that way, if it would work for you...

[RandyM1911]

Exactly what I did. Retail store of the builder I used was very fair with the pricing. I bought a new motor, seals, gaskets & impeller (just in case) and cleaned up all of the other parts thoroughly before reassembly. Fired right up and sounds sweet, much better than the old motor before the failure. I put a gallon of shock in the pool and ran the pump overnight so the SWCG could replenish the chlorine that was essentially gone after four days of no operation. Free chlorine levels came right up and the chemistry looks good across the board.

Other than a couple of green algae spots on the liner (which will scrub out), it doesn't seem any worse for the wear. Only my wallet was damaged in the process but a valuable (and expensive) lesson was learned as well. That being, if you let someone use you pool while you're away, even if it is a family member or someone you really trust, don't let them touch anything. No valves, no timers, no adjustments, nothing. Leave it as you found it or don't use it at all.

[aylad]

Yep, that's a valuable lesson. Here's the other end of that one...if you see a leak around the pump, even a very small one, don't ignore it--go ahead and change out that shaft seal. Ignoring it will eventually produce the same result that you had.....ask me how I know!

Glad you got it up and running again. Funny how that stuff always happens when it's hot outside, huh?

[RandyM1911]

True enough!

Although I can't say that I ever noticed any leaking around the pump at all. The majority of the corrosion was behind the motor mounting plate where it attaches to the front of the motor. Also under the front of the motor where the air cooling slots are located. But none of that was visible until taking everything apart.

I did notice some bearing noise in the motor this season and had planned to pull it (the motor) to have the bearings replaced after closing the pool in the fall. The bearing noise was noticeable but not horrible and I'm sure it would have made it to the end of the season (mid-September for me) had the seal failure not occurred. I may still rebuild the old motor and either keep it as an emergency back-up or see if I can sell it on E-bay. I can tell you that going forward I will be much more attentive to the sound of the pump motor and I'll be on the lookout for any signs of leaks or corrosion.

In the meantime, thanks for the help and the words of encouragement. It's nice to know I'm not alone out here!

[PoolDoc]

Although I can't say that I ever noticed any leaking around the pump at all. The majority of the corrosion was behind the motor mounting plate where it attaches to the front of the motor. Also under the front of the motor where the air cooling slots are located. But none of that was visible until taking everything apart.

You may want to check during a rainstorm, to make sure something is not causing water to splash up into the motor.