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elcb and borehole pump

Former Community Member
Former Community Member
Hello

I have a problem with a newly installed domestic borehole pump. This is to replace the original pump which after 20 years has given up the ghost.

The pump appears to operate satisfactorily except that it trips the consumer unit elcb on starting and only on starting. Resetting the elcb allows the pump to run normally. The time taken to push the elcb switch back up is presumably sufficient for some transient effect to end.


The house wiring is exactly the same as for the original pump, which ran satisfactorily for 20 years.


The installer has carried out all the tests normally conducted on the pump and pump cable (continuity, insulation, running current, etc.) and claims that the pump is not faulty. Yet it trips the elcb on startup.


I will welcome any suggestions for a solution. The installer is a one man firm and is reluctant (to say the least) to change the pump.


Mike Lee
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  • Former Community Member
    0 Former Community Member
    PROBLEM SOLVED?

    Hello everyone

    I received a very prompt and helpful response from Proteus wfich said "In recent years, additional surge arrestor components have been added to our RCDs to reduce the risk of nuisance tripping from transient events, similar to what you explain here.We found that with the introduction of larger capacitors in white goods appliances, a higher percentage of devices were suffering from this issue. By adding in the additional components, this has reduced this issue considerably, so it may well be that the older RCD is susceptible to nuisance tripping from the transients created by the new pump. So in answer to your question, I do think that you're experiencing nuisance tripping issues because the RCD is susceptible to the transients present in the new pump."

    I have replaced the original RCD with an equivalent from their current range and (on the evidence of a few trial starts and a day's normal running) the new RCD doesn't trip on pump startup.

    Just to address a couple of points made during the discussion, the new RCD is described as type AC but the spec says it responds also to pulsating DC fault currents which I think is a characteristic of type A. Also the installation instructions specify that it must be top fed.

    Thanks yet again for all your help.

    Mike Lee
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  • Former Community Member
    0 Former Community Member
    PROBLEM SOLVED?

    Hello everyone

    I received a very prompt and helpful response from Proteus wfich said "In recent years, additional surge arrestor components have been added to our RCDs to reduce the risk of nuisance tripping from transient events, similar to what you explain here.We found that with the introduction of larger capacitors in white goods appliances, a higher percentage of devices were suffering from this issue. By adding in the additional components, this has reduced this issue considerably, so it may well be that the older RCD is susceptible to nuisance tripping from the transients created by the new pump. So in answer to your question, I do think that you're experiencing nuisance tripping issues because the RCD is susceptible to the transients present in the new pump."

    I have replaced the original RCD with an equivalent from their current range and (on the evidence of a few trial starts and a day's normal running) the new RCD doesn't trip on pump startup.

    Just to address a couple of points made during the discussion, the new RCD is described as type AC but the spec says it responds also to pulsating DC fault currents which I think is a characteristic of type A. Also the installation instructions specify that it must be top fed.

    Thanks yet again for all your help.

    Mike Lee
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