No pressure in new well

[Mckenzie]

Last year we had a 150' drilled well with submersible pump installed for a new house. The house is nearing completion and we are trying to get the well online. From the well there is a check valve, a 40/60 pressure switch, a 35-gal Flex-Lite pressure tank, followed by a hose bibb with pressure gauge. I've checked the pre-charge pressure on the tank and it reads 38-psi. When the power to the well is on and all faucets are closed, the pressure gauge reads 40-psi. When a faucet is opened, the pressure gauge almost immediately drops to 0-psi. Water will flow fairly steady from a hose connected just after the pressure tank for about 60-secs and then stop for 30-40-secs, then flow at more of a slow dribble for 60-secs, and repeat. I've double checked wiring several times and ensured the pressure switch is receiving proper voltage. I've also and disconnected and rebuilt all the interior set up to check for clogs, etc. All equipment is brand new, though the well pump did sit unused in the well for the past year. Any ideas what my problem could be? Thanks for any help.

 

[Reach4]

1. Wrong pump, such as using a 20 gallon pump when a 7 to 10 gpm pump would have been much better. My best guess.
2. Out of water? Expect air in that case.
3. Obstruction, but then why the stopping? Maybe too little flow to cool the motor. No, not partial obstruction, because then the pressure would be higher with no flow.

What diameter of well casing?
What pump?

 

[Sponsor]

 

[Valveman]

That pumping for a minute and quitting, then repeating, sounds like you are pumping the well dry. Need an amp meter to see what is going on. Might also let the well rest for 30 minutes, and see if it pumps better for a minute or two. Even a low producing well will usually let the pump run as it should for a minute or so before it drops off.

 

[Mckenzie]

The well is definitely not dry. I've taken the cover off and can see water in the casing when I shine a light in, probably 20-ft down. The water level does not drop (or else barely drops) when the pump is running. When it was drilled it was rated for 10-gpm at 150'ft depth, they first hit water just below the bedrock, at about 30-ft. I don't think I was ever told what size well pump was installed, but I'll look around for some paperwork and update if I find out. I'll try to get an amp meter tonight.

Also potentially of note: I've noticed the pressure switch contactors are still connected when the pump turns itself off - perhaps that is a sign of an issue with the current in the electrical?

 

[Valveman]

Also potentially of note: I've noticed the pressure switch contactors are still connected when the pump turns itself off - perhaps that is a sign of an issue with the current in the electrical?

Ahh OK! That means the overload in the motor is tripping, which is why the water drops off after a minute or so. Then when the overload cools, the pump just magically comes back on. Overloads tripping for a reason. Make sure you have the correct voltage. Other than that the pump has probably cycled itself to death over time, which is what usually causes them to fail and trip the overload.

PS; The water trickling after the pump shuts off probably means your bladder tank is also bad, which is also caused by too much cycling.

 

[Mckenzie]

You were completely right!

Turns out the breaker was undersized, I had the well pump wired to a 20-amp fuse in the breaker panel, should have been 2-20's (sorry if lingo is off here, not electrically-savvy). So it was getting some power, but not nearly enough. Took the pump installer about 2-mins on site to find and resolve the issue. Thankfully we caught it early enough along to not do any permanent damage to the pump/tank. Water is flowing like a jet now.