Design on 17th Edition Consumer Unit

[hutch6447]

Hi all, just wondering about these Regs on installation.

• Socket outlets for general use in domestic installations must have the additional protection of an RCD not exceeding 30mA (regulation 411.3.3)
• All circuits in locations containing a bath or shower must be protected by an RCD not exceeding 30mA (regulation 701.411.3.3)
• Cables buried in a wall or partition at a depth of less than 50mm, and not mechanically protected by appropriate earthed metal, must be protected by an RCD not exceeding 30mA (regulations 522.6.6–8)
• To prevent nuisance tripping, unnecessary hazards, and minimise inconvenience, circuits should not be connected to a single upstream RCD (regulation 314.1)
• Separate circuits shall not be affected by the failure of other circuits (regulation 314.2)

Right say you want to install Main Switch/ 3 circuits on RCBO's Lights up/down and outside lights and the rest of the circuits Sockets up/down, cooker, shower protected by an RCD.

This meets most of the requirements, so if it will not meet circuits shall not be affected by failure of others can this still be installed, designing it to minimise this?

 

[Dunc]

Perfectly acceptable in my opinion. Better then a dual RCD unit. The only way to meet the bit about single faults affecting other circuits is to fit all RCBOs but that generally gets knocked on the head by pure economics.

 

[hutch6447]

As i am leaving the forces i have got 12 years behind me as a sparky but i am struggling with domestic regulations, so am i to believe that as long as it meets a few of the requirements and the customer agrees to it then it is fine?

 

[GLENNSPARK]

nowt wrong with a split load configuration...such as a 5+5.......down lights...on the same side as up sockets....and vice versa.......this is for safety purposes.....as you dont want the whole house plunged into darkness...should one of the RCDs let go.....need to be sure that there aint a 'borrowed neutral' though when fitting these to an older install.....dont get me wrong...a 'high integrity' c/u is better but its still about cost and if a client wont see it.........

 

[telectrix]

as previous posts. with a dual RCD CU, the circuits are split between the 2 RCDs so as to minimise inconvenience should 1 RCD trip. will not completely isolate a trip to 1 circuit.