> > Hello,
>> > I wish to control my garden water feature from a wall mounted switch. I >> have
>> > bought an RCD fused spur to protect against faults.
>> >
>> > For cosmetic reasons, I would prefer to switch the water feature on and >> off
>> > by using the test/reset buttons on the RCD. Is this possible, or do I >need
>> > to install a separate switch between the RCD and the water feature? >> >
>> Thats what I did.
>> Subsequent to fitting the water feature supply I changed the main CU for a
>> split load one.
>> Guess what happens now if I press the test button on the RCD spur? >> ...
>> Yup, half the sockets in the house are tripped off :-)
>>
>>
>
>2 problems (I think)
>
>1. The test button works by supplying a current to earth, to trip itself.
>Without a time delay RCD on your CU (which would not be suitable anyway)
>there will be no discrimination, and the house RCD will trip. So for the 2nd
>poster (as I'm sure he knows) I can't see why the extra RCD would be needed,
>unless for some reason he wanted to run it on a non-RCD circuit.
>
>2. I'm sure I read somewhere that the test trip feature was not up to
>switching high current on a regular basis, and *should* soon fail if this is
>carried out whilst a significant load is placed upon it (maybe a pond pump >is ok?). >
>I'm not really sure in this area so somebody please chime in a help me
>finish this post I've started!
>
>Alex
>
RCDs are not designed for regular usage like this, so there is no guearantee that they won't wear out mechanically excessively.
The trip button may or may not cause a trip of upstream RCDs - depends how it is implemented. A test button can introduce an imbalance across its own sensor with no leakage to earth, and if done like this should not trip other RCDs.