Blown 5 capacitors in 2 weeks

[Jim T]

My 2 wire 3/4 HP pump burned out in just 3 years, so I installed a new 3 wire 1 HP pump myself. But now the capacitor keeps blowing. I get water but it will blow the capacitor anytime I need to do something that requires allot of water, like laundry. The pump is in a 260' well at the 160' level and water is at 90'.
The pressure switch turns on the pump at 45 psi and turn it off at 52 psi.

The capacitor is 105-126 MFD 220-250 volt (the standard for 1 HP). Am I right to suspect the pressure switch or is something else going on?

When I check the ohms of the wires I get high readings then the specs on the franklin control box. Since I bought the pump on ebay from china, I am concerned about that but since I blew the other pump in just 3 years, that tells me something else is going on.

 

[Valveman]

45 to 52 is a very narrow bandwidth to cycle the pump. 40/60 is more common. What size pressure tank do you have? Because even with a large tank such a narrow 45/52 pressure switch setting will make the pump cycle on and off a lot. The part you are blowing is called a "starting capacitor". It is only used to start the pump. So you are starting or cycling the pump TOO MUCH. And burning a start cap is just the first sign that your pump is not going to last very long either. Pump/motors are also destroyed from cycling on and off. An easy fix would be to add a Cycle Stop Valve. Your only other option is to use a very large pressure tank and widen the pressure switch settings to 40/60, but even then the pump will still be cycling, just at a reduced rate.

 

[Sponsor]

 

[DonL]

The capacitor is 105-126 MFD 220-250 volt (the standard for 1 HP). Am I right to suspect the pressure switch or is something else going on?

I would suspect the control relay. What control box do you have ?

The start cap should be out of circuit if the motor is up to speed. Pump run time should not blow it, unless the motor start winding or relay is bad.

Good Luck.

 

[Reach4]

Tell us about those capacitors that you are using.

Ratings can be different. A BMI starting capacitor that says 220VAC is OK for 240 VAC operation. A capacitor marked 250V that is not specially made as a starting capacitor is not.

When I check the ohms of the wires I get high readings then the specs on the franklin control box.

I don't know what to make of that.

Buy a new pressure switch first thing. That should slow your failures. When your pump runs, how long does it run at a minimum?

The capacitor is 105-126 MFD 220-250 volt (the standard for 1 HP).

How was the original capacitor marked?

If you thought any old 1 HP put in to replace a 3/4 HP pump would improve the pump lifetime, it doesn't work that way. Is your new 1 HP pump a "10 GPM pump, or what?

 

[Jim T]

45 to 52 is a very narrow bandwidth to cycle the pump. 40/60 is more common. What size pressure tank do you have? Because even with a large tank such a narrow 45/52 pressure switch setting will make the pump cycle on and off a lot. The part you are blowing is called a "starting capacitor". It is only used to start the pump. So you are starting or cycling the pump TOO MUCH. And burning a start cap is just the first sign that your pump is not going to last very long either. Pump/motors are also destroyed from cycling on and off. An easy fix would be to add a Cycle Stop Valve. Your only other option is to use a very large pressure tank and widen the pressure switch settings to 40/60, but even then the pump will still be cycling, just at a reduced rate.

The tank is a 30 gallon tank. I don't think it is water logged or defective. The switch, when installed was a 40/60 switch. Does this mean the switch is bad?

 

[Valveman]

A CSV is not pricey when compared to a large pressure tank. You could put in a couple thousand dollars worth of pressure tanks and it would not stop the cycling for long-term uses of water like a CSV will do.

A 30 gallon tank only holds about 8 gallons of water. An 80 gallon tank only holds about 23 gallons of water, and a CSV with a small tank (30 gal is fine) will do a better job.

 

[Boycedrilling]

Blown capacitors are NOT the problem. They are a SYMPTON of the real problem.

 

[Reach4]

The tank is a 30 gallon tank. I don't think it is water logged or defective. The switch, when installed was a 40/60 switch. Does this mean the switch is bad?

The switch should be installed very close to the pressure tank, so that it does not see pressure spikes. Your gauge should be there too, so it is seeing the same thing. So what could it be? It could be that the pressure gauge is bad, or there is a clogged nipple. It could be that somebody tightened the differential nut (on the smaller spring) clockwise.

Adjust the differential nut if you want to raise or lower the
cut-out setting while keeping the cut-in pressure constant. The
differential nut is the 3/8-inch nut that adjusts the smaller of
the two springs in Models FSG, FYG, FRG, and Type G switches. Turn
the differential nut clockwise to increase the cut-out pressure and
counter-clockwise to lower the cut-out pressure. Adjusting the
differential nut will change only the cut-out setting while the
cut-in setting remains unchanged.​

Then adjust the air precharge to 2 PSI below the new lower pressure.

And yes, you may have a defective pressure switch.

What about my questions about the original and replacement capacitors? And a 30 gallon tank only has about a 7 or 8 gallon drawdown. That is not big enough for your 10 or 15 GPM pump without a CSV. That alone would not be causing your problems, however.

 

[Valveman]

That is not big enough for your 10 or 15 GPM pump without a CSV. That alone would not be causing your problems, however.

I disagree. That alone could very well be the entire problem. While some may get away with using a tank that is too small, most pumps won't last very long cycling like that. There are several people trying to make copies of the Cycle Stop Valve because it works so well for applications like yours. Some copy cats even have model names that sound a lot like Cycle Stop. But if you were buying a new Ford car, would you pay a little less for a Fard because someone told you it was the same basic car?