To fit or not to fit an RCD...that is the question

[eternaloptimist1]

My consumer unit already incorporates a 30 mA RCD. I intend to fit an external IP66 power point. My dilemma is whether I should have the socket with an RCD or without. Any comments greatly appreciated.

 

[ricicle]

No need if the circuit you are connecting to is protected by the unit RCD.
It would be wise to have the RCD tested though to ensure it operates correctly.

 

[AndyPRK]

my vote is without RCD, unless its a socket RCD which is less than 30mA.

 

[chivers67]

I wouldn't personally fit one, I would however fit an FCU serving it to enable easy maintenance and ability to switch off when on holiday etc.

 

[Taylortwocities]

my vote is without RCD, unless its a socket RCD which is less than 30mA.

And the upstream RCD is a time delayed one. (which it will not be).

RCDs do not discriminate on the basis of trip current.

 

[AndyPRK]

I was thinking more of safety than inconvience.

 

[ericmark]

For a special like supply to a pond where even small currents can kill fish then using a 10ma RCD may be a good idea however I have no information on how fish are affected but for standard out door supply the existing 30ma is good enough.

 

[PrenticeBoyofDerry]

There is no need to fit a second RCD, but as already been pointed out a double pole isolator would help prevent misuse and if an earth leakage fault appeared on the external socket, it can be isolated from the main supply, thus preventing power loss on the the other RCD protected circuits.
And i would be very wise to make sure that the RCD is actually working within it's parameters before installing an outside socket!