On 14 Aug 2018 19:01:49 GMT, dpb wrote:

Of course it depends on the pressure...looks like it ran just long
enough to get above the cut-in point. Remember, it doesn't pull in
until it gets _below_ the setpoint; soon as it's above it'll stay open
until it gets below again even if it hasn't gotten to cut-out. All it
takes is _just_ above and as far as the switch is concerned it's as good
as "stop".

And, yes, I'm sure there's an electromechanical assist in there so the
contacts will "make" and "break" solidly, not drift in and out solely on
the spring compression...

Thanks for confirming how the pressure switch works.

I ran some more tests today, where what appears to have happened is that
there may be an electromagnet of some sort because something snaps those
contact closed with a bit of force that I had to overcome with the wooden
stick and then it wouldn't re-engage (so it's not just a mechanical
spring).

I agree with your assessment.

Hopefully I'll test more for sure today as I left the booster pump ganged
circuit breaker off all night so there is no water pressure in the house at
this moment.