Time delay rcd

[Electroglow]

Hi all now when installing a new cu to a property when the tails or SWA I always install a 30ma time delayed rcd front end..

TT systems that is.

What's the harm in putting a rcd in before the cu on tn systems?

 

[PC Electrics]

"when the tails or SWA".....what? some text missing?

 

[SLIPSHOD & SLAPDASH]

I dont think i have ever seen a 30ma TD Rcd fitted.

 

[Electroglow]

Lol haha I ment 100ma... I think I was going to say about the rcd protection no matter what earthing system when the tails exeed 3 meter lol sorry

 

[green-hornet]

The main problem I find is actually getting hold of TD RCD's, I fitted out a school recently which was TT, after a delay we did get hold of a 100mA TD RCD, and used a micture of 30mA and 10mA RCBO's for the distribution.

As for placing an RCD in front of a TN system, I see no problems, though I would try to install without one if possible, if one was fitted it would always have to be a TD type, otherwise discrimination would never be acheived.