We recently lost water pressure from our submersible well. Upon
inspection I found the pressure control switch to be completely
blackened by soot. I assumed a bad switch, so I replaced it. The new
switch cut in fine, but at cutout the switch started arcing rapidly,
followed by a big flash and bang. So that's what happened to the old
switch! Pressure settings are correct, bladder pressure is correct,
tank has been drained, etc., but very rapid cycling at cutout pressure
remains. Any ideas? Bad controller, low water, leak in pipe?
Run the pump till pressure gets near where it would
cut off. Flip the breaker OFF just before so that the
pressure switch doesn't trip.
Run water and see how much water is consumed before
the pressure drops to where the switch would normally
This will tell you if the bladder accumulator is
Arcing might be due to Start winding not opening,
but would not account for the rapid cycling.
If the air pressure is correct, 1-2 psi less than cut-in setting, with
no water in the tank, then you have serious blockage between the
switch and pump, or an electrical problem.
Do you have any filter or shut off valve before the pressure tank/
Do you have a control box for the pump, usually on the wall and the
electric line from the switch goes to it and then on to the well/pump?
Are absolutely sure the pressure tank is totally empty of water after
draining it? Wobble it, it should be light and no water above the
bladder sloshing around. You don't get water or water vapor out of it
when you spritz some air out of it?
If no to all that, then call a pump guy, well driller or only a
plumber that can service and pull a submersible pump (most don't/
Quality Water Associates
On Mon, 18 Jun 2007 10:34:31 -0700, Gary Slusser wrote:
If the OP is having those kinds of problems with the switch he could have
a short of the electric cable going to the submersible, sometimes caused
by the loss of the support of the pump and the cable getting stretched
over the top of the well casing. Happened to me once.
That's unique one... :) "Loss of support" of the pump would be a
complete break of the discharge line and there would be no water
discharge in any installation I've had. How is your pump supported?
I agree from symptoms OP's problem almost has to be electrical. At least
I can think of a way to get a real pressure fluctuation to cause such a
rapid cycling of the pressure itself. Deadhead or full bladder cause
the cutoff, certainly, but what can cause such a rapid pressure loss
that isn't readily apparent is the problem I'm having...
Don't suppose there's some bizarre way corrosion in the pressure-sensing
line could cause it? OP ought to check that for sure, anyway, though
one would presume that would have been done when replaced the switch.
Oh, another diagnostic would be what did the indicated pressure do
during this episode? (Assuming OP had the presence of mind to notice
while watching the spitzen-sparkzen... :)
The nylon support rope broke (also wore thru over the side of the casing)
and the electric supply cable supported the pump. Had no idea until it
wore thru the insulation and shorted on the casing. The discharge
line and tubing remained intact. Pretty crummy install job which was
corrected many years ago. I now use the well for outside water, we've long
since switch to city provided water.
I doubt it, the OP was probably consumed watching the pretty blue sparks. :)
I'm still curious how that is...why wouldn't pump be hanging on the
discharge pipe w/ a snubber around the bottom pipe section against the
casing wall? I can't figure how the pump can drop lower than the length
of the discharge pipe which should be much less "stretchy" than the feed
Inquiring minds and all that... :)
I can't tell you for sure it was long ago maybe 1974 and I was in my
teens. I just remember the well guy finding the pump being held up by the
tubing and elec supply line and the nylon rope broke. The pump was pulled
and things were redone, maybe even the pump was replaced like I said it
was 33+ years ago.
I've talked with several local experts, who can't figure this one
out. As a last resort, I installed another pressure switch (the third
one in 30 days) and it is working normally for the moment. We'll see
what happens next.
Stumps me too. If the pump was reaching cut-out pressure but the
switch then started arcing....Shouldn't be a pump problem causing that
(not to say that you might not have a pump problem). Hard to think of
why a new switch wouldn't just shut off if it did truly reach cut-out
other than a defective switch.
On Mon, 18 Jun 2007 11:20:14 -0700, mustang wrote:
Well (no pun intended) report back if you find something. If you blew a
couple switches you've got pump or electric supply line problems. The
first downhole pump I had was suspended by a thick piece of nylon rope
when over a period of ten years cut through from the torque of the motor
twisting it. That allowed the electric supply line then to become the
support and shortly thereafter grounded out one leg of the 220v. But at
first it was intermittent and I went through a couple switches over a
period of a month before calling someone out who discovered the problem.
No telling if you have the same setup because you haven't described it but
you might want to take this into consideration unless it's been ruled out
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