Jet Pump - Pressure switch only about 10lbs drop before switch turns on

[jabooakes]

I have 2 well points at approx 25 ft. I have tested both and get about 20 GPM combined.

I have a 1hp Goulds jet pump with a 4.5 gallon pressure tank attached. I also have a pressure gauge.

I have emptied the pressure tank to ZERO PSI to get the cut off. The pressure switch is a 30/50.

I have adjusted the large spring and small spring and have the cutoff around 58 PSI. I unplug the pump and then allow the water to slowly exit. Watching the pressure gauge I only get about 10 to 12 PSI drop before the switch engages.

I have also witnessed that the pressure switch spring seems to "bounce" as pressure is building toward the top end.

I have also attached pic if this does not show.

My tank I simply want a little buffer and I am using it for irrigation only. Maybe I am missing something or doing it all wrong. Any help would be appreciated.

Thanks!

 

[Texas Wellman]

I'm not sure what you mean by "emptied the pressure tank to zero psi". The tank needs to have about 2 psi pressure below the cut-on for the pump, usually either 28 psig or 38 psig for a 40/60 switch.

Sometimes the springs on the switches get out of whack and you cannot get them set right. Put a new switch on and see if it helps.

 

[Sponsor]

 

[jabooakes]

I started with the tank at Zero PSI air in it.... Basically I wanted to make sure the tank wasn't playing a role in the fluctuation in pressure to I just wanted it to be what built up in the tank. So the cut off is around 58 when the switch clicks off. I slowly let out water with Zero PSI in tank from air and allow the tank to empty slowly watching when the motor click on and it only drops 10-12 PSI before if cuts back on. I thought it was to be 20PSI range plus whatever additional I increase cutoff with nut #2. Maybe I will just get them to send another switch. it is a brand new jet pump with PS built in.

 

[Valveman]

I would try a new gauge first. That one maybe clogged and has a delay in the reading.

 

[DonL]

Maybe I will just get them to send another switch.

I would not mess with the small differential adjustment.

Once you do it can be tricky to put back to normal.

Good Luck.