Quote:
Originally Posted by tommymcg
Hi
I recently purchased a water feature from B&Q and when the installation was complete it was noted that when the pump was switched off it tripped the ELCB on the consumer unit
I understand that the amount of inductance generated by the motor causes a spike when the unit is switched off and this is the cause of the ELCB tripping. Further research has revealed that a suppression or "Snubber" circuit which is comprised of a resistor and capacitor in series will eliminate this type of problem.
Has anyone else experienced this type of problem and are these type of "Snubber" circuits available for purchase?
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Regarding your elcb tripping the good news is it seems to be working but as an electrician there is not always a straitforward answer to seemingly simple "Quirks" of electricity Firstly if the switch you are using to switch it off should be a double pole switch once switched off ther should be a permanant dissconection between the pump and the elcb controling that circuit hence any assumed spike from the motor has no where to go except to earth and since it should be double insulated as a pond pump therefore my guess is that there is a fault with either the switch arrangement or the pump insulation
Since b&q operate one of the best returns policies I know of I would consult a friendly electrician who can meter the windings of the pump and advise on any switching changes you may need...You don't say if you have a Split load Consumer unit or not As far as the inductance is concerned once dissconected since no current is flowing in the motor there should be no inductance unless the motor has a permanant magnet. don't faff about with snubbers and such as you would have to double insulate them to make them safe Just change the motor at B&Q and If the Replacement does the same Get your money back.