are rcds supplementary protection

[chrisgjudd]

newbie needs to clarify if you have a 17th edition split load rcd consumer unit on a tt system which circuits should be rcd checked at 5 times trip current, and now that we have to rcd protect cables less than 50mm in walls does this mean the rcds used are supplementary protection.Or is it just were disconnection times cannot be met....?? ]

chrisgjudd

 

[Bclearnersparks]

AFAIk to comply with 17th edition reg 522.6.6 which talks about cables installed less than 50mm from surface and not having an earthed metallic shield or enclosed in earthed metallic conduit then an rcd has to be used complying with reg 415.1.1 for installations not under the supervision of a skilled or instructed person.

Checking reg 415.1.1 this states use of an 30ma rcd operating at no more than 40ms at 5*delta N test current. This is classd as Additional Protection.

So yes this applies to all circuits.

Hope this helps anybody else care to expand on this?

 

[kme]

I`ve replied to the other posting of this thread

 

[SPECIAL LOCATION]

newbie needs to clarify if you have a 17th edition split load rcd consumer unit on a tt system which circuits should be rcd checked at 5 times trip current, and now that we have to rcd protect cables less than 50mm in walls does this mean the rcds used are supplementary protection.Or is it just were disconnection times cannot be met....?? ] chrisgjudd

Deja Vue? ?:|

 

[Bclearnersparks]

where is the other thread ? thanks

 

[SPECIAL LOCATION]

where is the other thread ? thanks

Tis in Q&A's & Inspection & Testing Sir!

Mirror mirror on the wall............................... ]