Pump quits every night

[Ironjim]

My well pump keeps quitting overnight. Each morning I have to play with the switches and electricity to get it going again. I cleaned off the contacts on the pressure switch and checked all the wires on it and the control box (submersible pump). When it cuts back on the psi is perfect at 40. Today I was about to change the control box when I struggled getting the electric conduit off. As I was going to google this I decided to leave the power on but to turn the well off with the cut off switch outside (its basically the same as a light switch). When i returned 5 minutes later on a whim I switched it back on and the pump came back on. Now I'm thinking the cut off switch might be bad or in need if replacement. Any thoughts?

 

[Valveman]

Sounds like the overload in the motor is tripping. It is an automatic overload and resets itself after a certain time. But if it is tripping during the night, you probably have a bad check valve or a leak in the pipe that lets the pump cycle on/off all night. Cycling on/off is what destroys pumps, and one of the first signs of trouble is the overload tripping on occasion.

 

[Sponsor]

 

[Reach4]

It could be the start capacitor in the control box is going out. Replacing the control box would give you a new capacitor and more.

Your switch is outside. Is the control box outside? I would think that the switch would be before the control box electrically. If that is the case, a bad switch would show up as low voltage coming into the pressure switch terminals.

Yes, you could have an intermittent switch, but capacitor seems worth considering. So why would the pump start during the day, but not so at night?

http://www.electronicshub.org/capacitor-characteristics/#Temperature_Coefficient says

Some capacitors are non linear (class 2 capacitors), these capacitors temperatures are not stable like class 1 capacitors, and their capacitance values will increase by increasing the temperature values, Hence these capacitors give a positive temperature coefficient. The main advantage of the class 2 capacitors is their volumetric efficiency. These capacitors are mainly used in the applications where high capacitance values are required, while stability and quality factor with temperatures are not main factors to consider.​

So my thinking is that during the warmer day, the failing capacitor has more capacitance than during the cooler nights.