RCD ADS current 2391 question

[ICE]

what is the operating current of an RCD used to provide ADS on a domestic TT installation with an earth electrode resistance of 150 ohm?

Is it a trick question?

 

[securityvillage]

No you use

50 divided by RA(150) = I delta n

Hope that helps

 

[Guest123]

Hey.

I would say 30mA regardless of the RA as on TT the max disconnection time for an instantaneous trip i.e 5 x iDN = 150mA, is 0.2s.