Meat Plow wrote:
On Mon, 18 Jun 2007 10:34:31 -0700, Gary Slusser wrote:

On Jun 18, 11:40 am, mustang wrote:
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?
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.

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...

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