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?

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.

when the pump was switched
off it tripped the ELCB on the consumer unit

Take it back to the supplier.

Has anyone else experienced this type of problem and are these type of
"Snubber" circuits available for purchase?

Don't mess about, take it back, get your money back.

Al.

Hi
Thanks for your reply and my apologies for not replying sooner I have returned from holiday.
Unfortunately it is not as simple to return the water feature as it is built into a raised focal point and slabbed. The cable has been properly jointed with a resin filled armoured joint box(completed in dry condtions)and would have to be cut in order to rejoint.
Due to the construction of the house the only feasible method was to spur a feed from a socket into an IP junction box and using a simple 3-way light switch to switch the lights (2circuits) and water feature. I am not convinced that the pump is faulty and this cannot be an isolated case.
Any additional advice you can provide would be most welcome.

On Aug 2, 3:49 am, tommymcg
wrote:
Hi
Thanks for your reply and my apologies for not replying sooner I have
returned from holiday.
Unfortunately it is not as simple to return the water feature as it is
built into a raised focal point and slabbed. The cable has been
properly jointed with a resin filled armoured joint box(completed in
dry condtions)and would have to be cut in order to rejoint.
Due to the construction of the house the only feasible method was to
spur a feed from a socket into an IP junction box and using a simple
3-way light switch to switch the lights (2circuits) and water feature.
I am not convinced that the pump is faulty and this cannot be an
isolated case.
Any additional advice you can provide would be most welcome.

garden-helper;731882 Wrote:





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.

--
tommymcg- Hide quoted text -

- Show quoted text -

Hi Tommy, Did you find your problem?

Hi
Thanks for your reply, I have contacted B and Q and they passed on the manufacturers details Heissner Ltd Coventry.
A very helpful chap informend me that the company had not supplied a 240volt water feature pump to B and Q for 4 years, this item has been moved around various branches prior to me purchasing it.
I again contacted B and Q and they have agreed to supply a low voltage pump complete with an IP rated transformer plus a small amount of compensation.
Hope fully this will be a sucess and it will be happy days in the garden

Regards

Tommy