Pump Runs Non Stop trying to reach cut off pressure setting

[TrapperMark]

Pump - Franklin 1/2 hp 2 wire submersable (installed 1 week ago)
Switch - Franklin D Switch (new last week as well) 30/50 psi cutoff's
Pump Depth 100ft
Well Depth 120ft
Pressure Tank - Redline 40 gallon
Pump Wire changed 5 yrs ago
Water Line - age unknown

O.k, I have looked over the posts trying to find a solution to my problem but mine seems to have a twist to it..

One month ago I suddenly lost water pressure, checked gauge it was zero and the switch was tripped open. Reset switchs and had instant recharge of line. Then the low pressure problem would happen when we would do a LARGE load of laundry so I thought we were low on water but the fuses would not burn out. Suddenly last week everything went dead along with the pump fuses blown. I figured out it was the pump and replaced the pump and while i was at it i replaced the switchs and everything worked as it should. When i changed the pump I observed we had lots of water. Yesterday, we lost pressure, switch was tripped open and the fuses were blown. I replaced the fuses and engaged the switch to power up the pump. The pump works trying to build up pressure to 50 psi but it cannot do it. I have tripped the switch and observed my pressure gauge and there is no drop in pressure and from that I am figuring my check valve located below my tank is working properly (?). To not overload the pump I kept it "off" all night. I am thinking that the reason my original pump went was because it was going non stop and this pump tripped yesterday because of the same thing. WHAT is the cause of the pump not achieving the correct pressure ?? When I pulled the system last week the water line looked fine and I inspected all the pwr wires closely looking for breaks but found none. I hope all this is not too confusing in my explanation... Many thanks

 

[VAWellDriller]

What is the pump model and what is the water level?....from what you describe it sounds like the pump is incapable of building cut-off pressure....maybe a bad pump pick, maybe just a bad pump out of the box???

 

[Sponsor]

 

[Cacher_Chick]

If it's not the pump, you have a leak. It could be the drop pipe, the lateral, or the seal at the pitless adapter.

 

[LLigetfa]

What is the pump hung on? My guess is PVC and a near-meltdown softened and deformed it to the point you now have a leak near the pump. The topside checkvalve is likely masking the leak.

 

[TrapperMark]

VA- Don't think the pump is too small, it worked for a week b 4 things went south.
Cacher- My lateral is after my tank and check valve but i am thinking the drop is the problem. Not sure what a pitless adapter but i think u mean the piece attached to the pump...
LL - Pump is held on with a Large Metal nut/adapter rig that has a dinky check valve inside ( i think about the valve).

Leaning twds pulling and changing the adapter out, not sure of the age but it surely is not anywhere's new. Atleast i will check 1 more thing off the list of variables. Problem is where i live it is hard to get stuff without a drive. My pump manual mentions voltage issues but how often does that really happen????? Everything else in the house works fine including the 230v stuff.

Thanks for all the input and keep'm coming.

 

[TrapperMark]

I have replaced the line into the well and the fittings at the pump and nothing changed so it has to be the pump. There is now nothing left that has not been changed or checked. VAWELLDRILLER was correct in his diagnosis. My pump brand is not a franklin but Mastercraft ( canadian tire brand) that is much lrger and heavier than my franklin, it also is made in China.... The pump can reach mid 40`s psi so i am adjusting my pressure switch to cut out at that and live with it for now but i hate to loose that extra pressure.