Can you use an RCD as a switch?

[T i m]

Hi all,

Sorry for repeating a similar question but I would like some guidance so I can help some family friends (before they do something silly).

I am possibly going to help them run some armoured cable to feed a small water feature at the bottom of the garden.

I was hoping to take a spur from the ring in the conservatory, throught a flush mount, rear exit RCD through some conduit / T&E to a waterproof junction box on the wall outside then armoured to a waterproof 13A socket on a pole near the 'feature'.

The questions.

1) Will this setup be ok (code and safety)?

2) Will it be ok to use the RCD as a 'switch'' (not sure how often they will turn it on / off .. possibly on all summer and off in the winter or maybe on in the day / off at night?)

3) Will it be ok to use 1.5mm 3 core for a single 13A socket (about a 10m run) (because a mate has 1/2 a roll doing nothing )

4) If I can't use the RCD as the switch, can I use a flush type switch and if so what would it need to be (eg illuminated, double pole etc) and would it go before or after the RCD?

All the best and thanks for your time in any case ...

T i m

[Christian McArdle]

I would use an immersion heater timer for this, such as:

with a 30mA RCD fused spur, such as:

will enable automatic shut down at night without the need to lie in bed hearing it and wondering if you can be bothered to get out of bed again. It will also give a simple override facility (possibly even a 1 hour boost) for when guests arrive and it is currently off.

The RCD spur isn't necessary if the circuit is already protected by a 30mA RCD, which under current regulations, it probably should be. If so, replace the timer with one with a built in FCU, such as:

[T i m]

want it on 24/7 / 365?

a double socket?

[T] Good point .. though it's one of the tricke type features (not a fountain) and is 10m away at the bottom of the garden. I'm not sure you would hear it even in the garden but it's good to have the option of a timeswitch before rather than after eh! ;-)

It

[T] Ok .. I'll give her a ring and ask her how she intended to use it ..

[T] And I believe *is* (I'll check when we go round next). Isn't there an issue with nuisance trips and hence the other RCD (or will it still trip the main RCD in the CU anyway?

If so, replace

of the different bits together ....? )

Loads to think about ... thanks ;-)

T i m

[Christian McArdle]

It will still trip the main RCD. The main one is more likely to blow than the individual one, as it is already made more sensitive by quiescent leakages on the other parts of the circuit.

Yes, this does everything you need, if the circuit already has a 30mA RCD.

Christian.