s type rcd

[copey84]

Hi all, looking some advice on s type rcds. Basically can you use them on tt installations for earth fault protection on circuits that don't require additional protection? Know that on a tt installation disconnection times of either 0.2 sec or 1sec must be achieved depending on circuit, but with the delay on the rcd will they be achievable?
Appreciate any advice, thanks!

 

[Guest55]

Hi all, looking some advice on s type rcds. Basically can you use them on tt installations for earth fault protection on circuits that don't require additional protection? Yep.
Know that on a tt installation disconnection times of either 0.2 sec or 1sec must be achieved depending on circuit, but with the delay on the rcd will they be achievable? Wont make any diference , disconnection times are for the mcb.
Appreciate any advice, thanks!

Regards Pete.

 

[Engineer54]

Hi all, looking some advice on s type rcds. Basically can you use them on tt installations for earth fault protection on circuits that don't require additional protection? Know that on a tt installation disconnection times of either 0.2 sec or 1sec must be achieved depending on circuit, but with the delay on the rcd will they be achievable?
Appreciate any advice, thanks!

Let's say it would be prudent to have an up front S type RCD as additional protection on a UK domestic TT system!! lol!!

30mA RCD protection on TT systems are not classified as additional protection, They are a Prime means, as they are generally the ONLY means of achieving TT system max disconnection times. It is the RCD that will disconnect the supply under earth fault conditions, NOT the MBC as has been indicated above....