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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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  • 0
    I can speculate, but I cannot see what I am speculating about, a picture of the consumer unit arrangement would help.


    If the RCD is in the tails it can apparently make a difference as to which way around it is installed, feed in at the bottom rather than the top.


    The starting current raises the neutral voltage more than the running current, so if there is a neutral insulation fault to earth it would be more prone to trip on starting rather than when running. But the fault could be in the installation rather than the pump or it’s flex, however it’s not a particularly powerful pump.


    Are you testing with testers or just bang testing to see what trips the device?


    Andy Betteridge
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  • 0
    I can speculate, but I cannot see what I am speculating about, a picture of the consumer unit arrangement would help.


    If the RCD is in the tails it can apparently make a difference as to which way around it is installed, feed in at the bottom rather than the top.


    The starting current raises the neutral voltage more than the running current, so if there is a neutral insulation fault to earth it would be more prone to trip on starting rather than when running. But the fault could be in the installation rather than the pump or it’s flex, however it’s not a particularly powerful pump.


    Are you testing with testers or just bang testing to see what trips the device?


    Andy Betteridge
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