RCBO neutral & earth tails

Badged01 · Feb 21, 2014

I vaguely remember it being something to do with the minimum cable length (RCD to N Bar) to enable the RCD to work to spec. Cant remember the technical reasoning behind it .....

Engineer54 · Feb 21, 2014

Maybe someone should have asked him what length of standard cable is mandatory for a double pole or a 1 ph + N RCBO, where neutral tails aren't provided?? I'd like to hear this Tony Cable's reasoning behind this little gem!! lol!!

It's an old Wives Tale, ...end of!! lol!!

Engineer54 · Feb 21, 2014

Badged01 said:
I vaguely remember it being something to do with the minimum cable length (RCD to N Bar) to enable the RCD to work to spec. Cant remember the technical reasoning behind it .....

Is that why manufacturers provide longer tails for (10KA) RCBO's to be mounted in 3 phase DB's than those for standard single phase CU's (6KA)?? .... Or is it because the tails need to be longer to reach the neutral bars in the larger 3ph DB's??.. lol!!!

Are there any ''warnings'' on manufacturers literature that comes with the RCBO's in the box?? Nope!! none that i've ever seen anyway...

spark 68 · Feb 21, 2014

Straight from the horses mouth, for Schneider at least.

Taken from Schneider's FAQ

i=p/u · Feb 21, 2014

Nothing worse nope!!! Lol heeeeeeee

Engineer54 said:
Alas, just another old wives tale i'm afraid. There is no reason whatsoever not to dress and cut to size to suit the installation.

I'd say that virtually every RCBO's neutral tail and functional earth lead has been, or will be dressed, and cut to size on our project. There is nothing worse than seeing a DB/CU filled with unwanted lengths of RCBO tails and leads. Get them dressed and cut to size, not forgetting to fit a suitably sized pin ferrule...