clarification on 705.411.1 (iii)

[J@mes]

"In all other circuits, RCD's with a rated residual operating current not exceeding 300mA"

Can I take this to mean that the cable from my 415v board that is supplying my 230v board about 30 meters away must be protected by a 300mA RCD?

Or can the cable just have overcurrent protection and then the circuits have their own RCBO protection in the 230v board?

thanks, James

 

[Guest123]

Hey mate.

Off the top of my head your dealing with an agricultural installation??

What have you got as your main incomer in the 415V board??

Basically all S/O's need 30mA all other circuits i.e lighting heatinfg etc need 300mA.

Cheers.

 

[J@mes]

thanks for replying - yes its an agricultural installation!

Will have to look at what the main incomer is some time this week.

in the BRB it only mentions that sockets up to 32A needs 30mA, over needs 100mA and ALL OTHER circuits must have 300mA.

had it said ALL OTHER FINAL circuits, it would have been a bit more clear

ah having re-read the last bit of your post it should be fine without RCD protection on the cable as long as the final circuits (1xsocket, 2x main lights 1x security light) are covered by 300ma RCD's.

 

[Guest123]

Agreed.

Although if there are any circuits in the 415V board that are to do with the barn/parlour/shed, then these will need 30mA or 300mA protection also, would be worth advising client if there are.

Cheers.