rcd outside socket

[kye]

changed a cu today [upgrade to 17th]customer wants me to install outside socket useing his own rcd protected socket [ip code ok]by adding another rcd will i lose dicrimination and possible nuisence tripping to existing circuit that i can take a feed from.

 

[Sintra]

If the circuit is already protected by 30mA RCD then no need to install another. Just install an ordinary IP rated socket.

 

[kye]

that was my view .But i think that he has already bought the socket,if i install it will it cause any prob.

 

[Sintra]

Not really as only a faulty appliance plugged into it will trip both the socket RCD and circuit RCD. Just have to reset both.

 

[acat]

Have a look at 531.2.9 of BRB with reference to discrimination with 2 or more RCDs its on page 113


Chris

 

[Johno]

i would advise him to change it, but if he refused, i would probably fit it and just warn him that if he presses the test on the socket it would trip at CU.

 

[kye]

thanks for the help