RCD disconnection times help!!

[yesitsashock]

Im suppling distribution circuits and want to use the largest possible RCD available to avoid nuisiance tripping (its for outdoor street furniture and its a TT system). The Ze is 160.

The reg below says 1 second disconnection time but cant find anymore info in the regs about it. Closest I can find is a time delay 150-500 ms Thanks in advance


411.3.2.4 In a TT system, a disconnection time not exceeding 1 s is permitted for a distribution circuit and for
a circuit not covered by Regulation 411.3.2.2.

 

[Rockingit]

I'm not entirely sure what your question is here, however generally speaking RCD devices which provide time delay greater than 300ms tend to be the adjustable ELCB style - and are expensive!

However, I'm curious as to why if this is for street furniture that you're not TT'ing at each point of use with an individual 30mA RCD?

 

[yesitsashock]

I'm not entirely sure what your question is here, however generally speaking RCD devices which provide time delay greater than 300ms tend to be the adjustable ELCB style - and are expensive!

However, I'm curious as to why if this is for street furniture that you're not TT'ing at each point of use with an individual 30mA RCD?

I work with mostly distribution circuits, I was asking out off interest regarding the reg i posted about 1 second dis time.

The street furniture doesnt need a 30mA RCD its not "telephone kiosks, bus shelters, advertising panels or town plans" the street furniture is from a switched supply.