Pump cycling too frequently

Hey guys, we are irrigating about 5-6 acres, mostly drip lines and are having some problems...a little background; system was running fairly well with a 1 1/2 hp pump until capacitors started blowing regularly- on advice, purchased a 3hp centrifugal pump which burned out its motor in about 13 months, new motor worked fine all last summer/fall and recently killed a breaker then a capacitor, replaced capacitor (and breaker) lasted 4 or 5 days...had electrician check voltage and all looks fine. Pump had been cycling every 30 seconds or so @ 20-40 psi w/ 35-40 gal. pressure tank..a respected pump seller has recommended a CSV as the simplest remedy but we are very concerned with extra energy consumption. We pull our water from a spring-fed pond just a few feet below out pumps and push out a total of a mile or so of 2" pipe..I can hear our little pump cycling on about twice a minute as I write this...please help.

karmagic said:

..a respected pump seller has recommended a CSV as the simplest remedy but we are very concerned with extra energy consumption.

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Yet you spend just as much on electricity now and you're burning money buying pumps??

Actually if your pump is cycling that much, the CSV will decrease the electric bill. Not to mention making everything last years and years as it should.

You can also buy the correct pump that matches your flow, and with some switch adjustments, it will never turn off. WAY too big motors.

Probably the cheapest 3/4 or even 1/2 hp flotec pump would last decades in that use.

Or add some more drip line with bigger emmitters. Or add a rainbird to water the lawn with a valve to adjust until the pump runs steady.

You could mimic the csv with an outlet valve set to keep the pump at 38 psi. Do it on mine all the time.

ballvalve said:

You can also buy the correct pump that matches your flow, and with some switch adjustments, it will never turn off...

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You could also deploy several pumps and adjust each to turn on at a different setpoint. That way when one pump cannot keep up, a second will kick in, and maybe even a third if necessary.

Appreciate the input...As we speak our smaller pump (which is actually 2hp) is providing enough water for about half the crop field, if both were on there would not be enough pressure/volume to water...thats we we bought the bigger pump...we were also using more sprinklers at that time..our pond tends to get very low by the end of summer so we're trying to conserve as well, hence the alternate watering days while its still cooler weather...I've been trying to keep it all simple...when you say an outlet valve you mean just a faucet? perhaps running into the pond? thanks

No, the "outlet valve" would be a ballvalve that needs to be attached before the pressure tank/switch and any water lines. If you have a single flow rate to adjust to, just set the ball valve to keep the pressure in the tank less than 40 PSI (38 PSI as BV said) so the pump can't shut off. This is exactly the way a CSV works except that the CSV will automatically adjust to different flow rates. They use gate valves in the cotton fields around here to adjust the flow from the pump, so it doesn't pump more than the well can make.