Pump motor seized?

dws3

Active member
Dec 21, 2019
27
Dallas, TX
During the Texas Freeze two months ago, we lost power and everything froze. I didn't think to shut off the breakers to my pumps, so when power came back in the middle of the night 16 hours later, the pumps came on. Seven hours later, I walked out and heard my pumps screaming and sounding like they were tumbling rocks, and shut the breakers off. Then we lost power again for another 12 hours. Four days later, when everything thawed out, I turned on the pumps and everything worked! My waterfall pump was a little noisy (squealy), though. After a couple of weeks it quit working. When I turned it on, it hummed, then shut off. I finally got around to swapping out an older pump to get the lines flushed out (algae was starting to build up), and took the bad pump apart. Everything looks good, but the shaft on the motor will only turn back and forth, about 10 degrees. I haven't disassembled the motor, yet. Should I assume the bearings are bad and replace them? I already know that the mechanical seal between the motor and the impeller took a little bit of a beating, so will replace that. I'm just wondering if I should just shell out the $200 for a new motor - this one is less than 3 years old. Thanks for any insight y'all can lend...
 
What model pump is seized?

If a motor is only $200 I would start fresh and not have to worry about other problems developing.

@JamesW
 
It would be very unusual for the motor to lock up in a few days.

Not saying that it can't happen, but it should be confirmed to definitely be locked up before changing the motor.

Maybe the impeller is clogged or debris is in the fan?
 
I have removed the back half of the pump from the front half. I've removed the impeller housing and impeller. I've removed the backplate. Everything looks good, except the carbon face of the mechanical seal that was attached to the back of the impeller has a few spots around the circumference that are chipped on the edge, so I would plan to replace that. I'm now looking at JUST the electrical motor in its housing. Turning the motor shaft, either from the rear or the front, only allows motion for maybe a quarter-inch or so in each direction, even when applying fairly strong torque with a wrench, but I haven't really bore down on it. So it isn't the impeller, it isn't the capacitor. But it also isn't completely seized. I have not removed the guts of the motor from the housing, but that will be my next step. Just thought that maybe somebody else had experience with this. I'm pretty familiar with electrical and electronic components, having spent 10 years as a Navy Sonar Technician, and another 35 years in the Defense industry working Sonar, Radar, Electronic Warfare and Missiles, but I'm not a licensed electrician or electric motor expert. I replaced this motor three years ago, but I've never rebuilt a motor. Tomorrow, I'll pull the guts out of the housing and see what's what.
What model pump is seized?

If a motor is only $200 I would start fresh and not have to worry about other problems developing.

@JamesW
It's a Jandy Stealth SHPM 1.5HP uprated. Replacing the motor is kind of where I'm headed. Replacing the pump was so easy. If I start replacing bearings and seals, I'll probably regret it! But I was just curious about what it could be and if it was worth my time to repair instead. I'll still pull it apart just to see what kind of shape it's in.
 
The Stealth pump is a bad choice for a waterfall pump.

The Stealth pump is a high head pump and a fountain is a low head application.

The tumbling rocks sound was probably cavitation due to blocked pipes.

You should switch to a fountain pump or a variable speed pump.

A fountain/water feature pump runs at 1,725 rpm vs. a regular pump at 3,450 rpm. It also has a bigger impeller. Both combined give good performance at high flow and low head loss.

How much flow does this fountain need?

What size is the suction line for the fountain?
 
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