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Still making little progress

Written by: Rick Nason

When we bought the house we had a brief spell of difficulty with the water supply from the borehole, the pump would run and pressurise the system. The pressure switch tripped out at 2 bar and then the system would drain back into the borehole and the cycle started again. We didn't know this was happening and the first electricity bill was rather high prompting me to look for a cause.

After shutting off the system for a couple of days, it started up and worked well for a few weeks.

Then, suddenly, it just stopped. Resetting the motor overload caused the pump to run for a short time and then it just tripped out. Engaging some help we hauled the pump out of the borehole and checked it out - the rotor spindle was jammed up with some plastic debris. I suspect that it was originally a shroud for the spindle which had broken but without a reference device to compare I'm not sure. I freed the pump spindle and tested it dry for a few seconds - all seemed good.

Having reinstalled the pump and fired up the system it worked - until the pressure got to 2 bar. Then we were back to the same state as before, pump overload tripping out and the water draining back into the borehole. Sigh !!

Bottled water from the local spring for the time being.

Puzzle time. More electrical confusion every time I open a box or look into an accessory.

Here is today's quandry. This junction box feeds two separate lights, one of which has a two way switch setup.

IMG 20200206 192846

Clue: None of the green/yellow cables are earth, it seems to me like the installer was working with eyes wide shut.

3 comments on “Still making little progress”

    • I read some more info and I have some ideas. The non-return valve at the head of the pump must be faulty, maybe jammed open a bit with some debris. As the water drains back, the pressure drops and the switch fires up the pump. But, at this stage, the pump is being driven backwards by the water flowing down. It needs too much current to overcome the backflow and the overload trips out. Previously, the same thing happened but the rate of flow was very small and the pump worked to repressurise the system, though it was cycling every couple of minutes. Now the water drains away pretty fast - as seen on the manometer. When I put an open pipe on the pump it took just a few seconds to drain back with no vacuum behind it but the pump ran continuously until I switched it off. I´m going to get the pump out again and overhaul the whole thing. May need a new one but hopefully not.
      • Suspicion confirmed. Two non-return valves, one built into the pump and one supplemental, both of which are not functional. Pump stripped down to be cleaned, more debris removed. These devices are so simple after all, I don´t understand why they are so expensive.

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