Pressure vessel monitoring

  • A pressure switched pump in a below ground chamber provides domestic supply from a bulk tank, but you cannot hear the pump running even when standing on the pump chamber covers.
    When hosing in the garden recently I noticed that the pump was cutting in/out rapidly, caused by low air pressure on the pump pressure vessel. This may have been occurring for months unnoticed as the irrigators are automatic.
    The house supply incorporates additional NRVs and PVs, so under normal conditions the pump should not be stressed, but Murphy's Law always applies, if it shouldn't go wrong it will.
    The no-volts terminals on the contactor are always on for the pump pressure switch, exchanging the pressure meter for a pressure sensor is not viable since the meter is used to set the pressure switch up (they do need periodic replacement), so the only indication the pump is running might be a vibration sensor, the rapid pressure decrease signalled by reduced pump-off periods warranting physical checks.
    My puzzle is how might this be displayed via Domoticz? I had briefly looked at how on/off states might be indicated graphically, but found no simple solutions.
    A simple binary warning indicator may go unnoticed before being reset by the the domestic system.
    Any advice?

  • Hardware Contributor

    Hello, @zboblamont,
    I might misunderstand your problem, but why don't you use a virtual switch, and a script that will only be able to set this switch on if a too short pump-off period is reported by your vibration sensor ? Then if the period gets longer the real switch will be reset but the virtual switch will not ?

  • @nca78 Nope, you didn't misunderstand at all, my experience using Domoticz is limited to basics thus far... Will look into that..
    Before this PV problem arose, had been looking at recording daily pump run times for both the domestic-supply and borehole pumps, easy enough for the borehole circuit, but the domestic runs LevControl->Contactor->PressureSwitch->Pump, so the auxiliary no-volts on the Contactor is permanently closed, hence a potential solution using a vibration sensor. Thinking about this overnight it may be possible to rewire LevControl->PressureSwitch->Contactor to solve the on/off indication from the auxilary on the main Contactor.
    If the number of starts per 10 minutes/hour exceed a threshold , a separate alarm flag could be signalled by your suggested method.
    Many thanks...

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