Gould pump motor problems

[Corvette-ed]

I have a 1 1/2 HP Gould jet pump and the motors only last for about 2 years. It was installed when we built the house in 1999. The first motor locked up and burned out in about 2 1/2 years. I have replaced the motor for another 2 years and then replaced the bearings on the second motor once. It seems like I get about 2 years and then have motor problems. I now have a noisey motor again and will replace or rebuild soon. I've been told that a motor should last about 10 years. Any ideas?

The pump supplies water for my house and lawn irrigation. The well is 131 feet deep. In the house it's just my wife and I. I live in South Florida so the irrigation part is mostly in the spring until the summer rains come. The pump sits outdoors on a concrete slab.

[speedbump]

Are you near the Gulf or the Atlantic? If so, is the motor getting rusty from the salt air?

What brand are these motors?

The fact that your bearings go in two years tells me the motor is in a bad environment. Bearings should last around 7 years or so. The motor should last 15 years or better.

What kind, size and brand of tank do you have?

bob...

[Pumpman]

Although I don't know how your system is set up, I can tell you that it is very hard on pump motors that pull "double duty", that is, supply water to the house as well as an irrigation system. Most pumping systems are designed to meet the needs of either the house or the irrigation system, but not both.
Motor life is measured in starts. The more often a motor starts, the less amout of time (measured in months or years) the motor will last. Irrigation systems should be designed so that the pump runs continually while the system is operating. Often, the pump cycles like crazy, leading to a shorter lifespan.
A cycle stop valve may help your situation. Hopefully, Valveman will come by. He's the one to talk to about that.
Ron

[valveman]

Thanks Pumpman but I am not sure cycling is the problem. Cycling usually gets the start cap, pressure switch, windings or something else before the bearings. I hate to say it but it could just be cheap bearings. Bearings these days are the sealed type. (can't grease em) Metal in the bearings isn't what it used to be either. Bearing just can't take the heat like they used too. Could be the heat more than the salt environment because the bearing should be sealed. Check the cooling fan. Check for blockage in the air flow through the motor. If the pump is sitting in the sunlight, put a shade over it. I have also had to oversize motors to keep the heat low. Pump and motor companies like for them to run close to critical temperature. Then you need a new one every couple of years. Cycling on and off also causes heat to build up but I still don't think that is the problem. Especially no more irrigation than is being used. Best guess, cheap bearings, and running tooooo hot. A Cycle Stop Valve would let you decrease the irrigation zone size, which would make the motor pull less amps and not run as hot. Running high flow rates pulls the most amps, and causes the most heat. Lowering the flow rate, decreases amps and heat.

[h2oguyofnh]

Could you improve the environment for the pump?

[Pumpman]

Valveman - I agree that cycling probably isn't all the problem. But the heat caused by cycling can be. I've seen the grease run out of a motor bearing because it got too hot. I always recommend that irrigation systems have a pump separate from the house system, but I thought a CSV might help in this situation.
Thanks - Ron

[valveman]

I totally agree Pumpman. Cycling can creat a lot of heat. But with a 3 HP it usually at least melts a pressure switch before the grease runs out of the bearings. Melt a pressure switch or two, maybe burn a start cap, then bearings go out, probably cycling too much. Just bearings and no other symptom, I am just not sure.

[Corvette-ed]

Thank you all for your input.

I agree with the comments that the environment the pump is in is bad. It sits on a concrete slab at grade. That puts it close to the surface water. Yes, we did have 3 hurricanes pass through here in the last 2 years, plenty of salt water in the air. And, the pump does double duty as the house and irrigation pump. When I talked with the irrigation guy, he explained that each zone is sized with enough heads for flow that continuously runs the pump. That means it should not cycle and runs at about 35 psi during each zone. I can't say what quality the bearings are since I did not install them.

I think my next move is to raise the pump up to get it away from surface water. I'll replace the motor (it's an A.O. Smith), seals and gaskets. Then cast about a 12 x 15 inch concrete block 4 or so inches high on the corner of the slab where the pump sits. I can do this with minimal plumbing changes (add a short length of PVC to the inlet and a shorter nipple on the discharge). Then I think I make a sheetmetal cover, open at both ends to protect the side of the motor (air flow openings) but allow air flow around the motor.

I'll replace the bearings on the old motor, clean and repaint it. I'll put it back in the box with a new seal and gasket. Then we'll see how long the next motor lasts but I'll have the spare to replace it whenever necessary.

Comments???

Ed

[valveman]

Sounds like you are on the right track to me. Spare motor is alway good to have around. If you need it in a couple of years, no problem. But if the new one last as long as it should this time the spare may be stuck when you need it. Just need to spin the shaft by hand a couple of times a year on the spare and it should not be seized up when you need it. Wish you better luck this time.