discrimination advice

[zone77]

need advice please. i am adding 2 sockets in a kitchen and bonding gas and water mains.the circuit is a ring protected by 32 A bs3871 and the consumer unit has a main switch which is 30mA rcd. do i need to provide discrimination ( install ring into its own rcd DB) or can i leave it as it is.

 

[Spudnik]

I think you will be fine just doing your works and certificate accordingly, noting on the cert the deviation.

 

[solo2771]

regs only say it needs rcd protection having seperate rcd's just better and more conveneant.

 

[andrewcann]

ye that will be fine as long as the rcd works ok so may be worth toing a rcd test to make sure it still trip in the right times was its a old rcd

 

[Danny Pross]

Hi
I agree with previous posts.
I would emphasise the point about it being good practice to "divide the installation in to circuits ... to minimise inconvenience in the event of a fault".
Would it help to run the kitchen circuit from an RCBO?
My thinking is that if a fault occurred on the RCBO kitchen circuit - then it would not trip the main RCD and leave the whole house in darkness.

Or would it????

Just sharing thoughts - and interested in others' views.

D

 

[solo2771]

Hi
I agree with previous posts.
I would emphasise the point about it being good practice to "divide the installation in to circuits ... to minimise inconvenience in the event of a fault".
Would it help to run the kitchen circuit from an RCBO?
My thinking is that if a fault occurred on the RCBO kitchen circuit - then it would not trip the main RCD and leave the whole house in darkness.

Or would it????

Just sharing thoughts - and interested in others' views.

D

I believe in most cases of an earth fault both devices would trip.
Paul

 

[zone77]

thanx for your replies guys. iv e done job today and rcd tested fine so just noted it on cert