Pump Overheating

[Douglas]

I have appreciated the posts on this thread as I have planned my project. I live on a rural property that has a 30 foot dug well and a convertible jet pump that does a good job. However we run the risk of the well going dry in the summer. We also live 85 feet above a river that is down a fairly steep hillside we have terraced. In order to water our vegetable garden and plants on the terraces, I have decided to experiment with a 1 HP Red Lion convertible jet pump to bring water up from the river. I placed the pump two thirds down the hill - about 35 feet above the river. That means it must still push the water another 50 feet or so up to the top terrace where I have a pressure tank (20 Gals). The long term plan is that this will feed a drip irrigation system on the terraces down hillside. In the short term I am filling a rain barrel system on the top terrace to water plants at that level.

The pump is serviced by 12 AWG wire on a 20 amp breaker (115 volts) and runs well, however after about 10-12 minutes it gets very hot. After half an hour of operating the first time around it shut itself down, but I was able to restart it after it cooled off. Now I am running it for 10 minutes and letting it take a good break before restarting it. Obviously this is not ideal given my long term plans to use it for irrigation.

The water is being pushed up the hill in 1" pipe. The horizontal distance from the river to the top of the terrace is about 110 feet.

I wonder if anyone has any comments about the pump and its capacity. Is there anything to be done to prevent it overheating? Is this just a function of the work it is being put to?

 

[LLigetfa]

Put a submersible in the river instead of the jet pump.

 

[Sponsor]

 

[Valveman]

I don't know how it is working if the pump is really 35' above the river? A shallow well jet pump can only suck from about 25' max. But it can push water as high as 150' max. There isn't any pressure left to use a pressure tank/pressure switch as after lifting 110' it can only make a max of about 17 PSI at shut off. At 110' it will pump about 4 GPM with little to no pressure. As was suggested a submersible in the river would be much better, but still need one that can lift 110' plus build another 50 PSI, which is the same as adding another 115' to the 110' of lift.

The pump end of the unit should not be getting hot as long as water is running through it. The motor is fan cooled with air but will feel really hot, as that is the way they make them not last very long. But it should not be drawing over the max amps and should not be shutting off no mater what the pump end is doing. The extra pressure won't make it draw high amps and shut off. Sitting in direct sunlight or not having enough cool air to flow can cause the thermal over load to trip.

 

[Douglas]

Thanks for the replies. It may be 30' above the river: the jet pump has the ejector added and technically can draw up to 90'. You are correct that the pressure tank is playing no function. Right now the pump itself is holding steady at 30 PSI. I am averaging about 2.5 GPM at the top terrace. Yes the motor end does feel hot, and I am running it for 20 min segments right now. It has not shut itself off again. I am wondering if switching it over to 240 volts might make it more efficient and tax the motor less? It has very good ventilation and is shaded. I may yet switch to a submersible but am interested in seeing if I can get this to work.

 

[Fitter30]

Need the nameplate amp draw and length of wire to see if the wire size is adequate. Double check the motor wiring and tightness of all terminals.

 

[Valveman]

If the ejector is down by the river it can "push" water up 90'. But nothing can "draw" up more than about 25'.

 

[LLigetfa]

I am wondering if switching it over to 240 volts might make it more efficient and tax the motor less?

Yes.

 

[Douglas]

Thanks all for your input: I changed over to 230 volts which meant that the #12 wire was more than enough to accommodate voltage drop at that distance and with much lower amperage, and the pump is running much better: warm but not too hot, and now at least 8 GPM at the top terrace. For now I shall avoid a submersible...