Outside light RCD protection

[Spoon]

Any addition to an existing lighting circuit, will require RCD protection be provided for the existing part of the circuit, not just the addition

Not trying to be a pain mate but I thought, maybe wrongly, that if adding a light to a circuit it was just the additional circuit that needed RCD protection and not the whole circuit from the CU.

 

[Beeg]

Just to clarify, if I was to have it installed before the 18th edition is enforced next year, what would a sparkie need to do in terms of RCD/ switched FCU etc for it to meet current regs?
The fitting will be connected to the downstairs lighting circuit from an existing ceiling rose.
Cable will be clipped to wall around inside of porch and then pass through wall to light fitting at a depth greater than 50mm

 

[Midwest]

After the new year, the RCD protection will have to be at the Consumer Unit.
In domestic installations, anyway.

Not done any researhe yet on te 18h, Why in thu=is scenario would yt be nessessar at the CU, Not done any auto correct cos it is Satruday night,

 

[Deleted member 26818]

Recently we had this thread: Does this setup contravene any regs or is it ok? - https://www.electriciansforums.co.uk/threads/does-this-setup-contravene-any-regs-or-is-it-ok.167990/

It really thought that we had established that the origin of a final circuit is at the DB/CU?
Now if people want to consider an FCU to be the origin of a final circuit, then fine, do so.
Just remember Regulation 314.4:
“Where an installation comprises more than one final circuit, each final circuit shall be connected to a separate way in a distribution board. The wiring of each final circuit shall be electrically separate from that of every other final circuit, so as to prevent the indirect energizing of a final circuit intended to be isolated.”

For those of you who want to drag up the definition of a DB/CU, and say that an FCU is a DB/CU.
Just remember Regulation 421.1.201:
“Within domestic (household) premises, consumer units and similar switchgear assemblies shall comply with BS EN 61439-3 and shall:
(i) have their enclosure manufactured from non-combustible material, or
(ii) be enclosed in a cabinet or enclosure constructed of non-combustible material and complying with Regulation 132.12.”

Yes, with additions and alterations, only the new work has to comply with the current Regulations.
That’s fine if you are adding a socket to an existing socket circuit with no RCD protection, only the new socket and perhaps the new cabling will require RCD protection.
However, where the requirement is for a circuit to be provided with RCD protection, then in order to comply, the circuit will require RCD protection.

 

[Deleted member 26818]

Just to clarify, if I was to have it installed before the 18th edition is enforced next year, what would a sparkie need to do in terms of RCD/ switched FCU etc for it to meet current regs?
The fitting will be connected to the downstairs lighting circuit from an existing ceiling rose.
Cable will be clipped to wall around inside of porch and then pass through wall to light fitting at a depth greater than 50mm

The scenario you describe will not require RCD protection.
In fact, if you design the alteration now, then you can install after the 18th has come into force and still not require RCD protection.

 

[AJshep]

For those of you who want to drag up the definition of a DB/CU, and say that an FCU is a DB/CU.
Just remember Regulation 421.1.201:
“Within domestic (household) premises, consumer units and similar switchgear assemblies shall comply with BS EN 61439-3 and shall:
(i) have their enclosure manufactured from non-combustible material, or
(ii) be enclosed in a cabinet or enclosure constructed of non-combustible material and complying with Regulation 132.12.”

Spin, You are probably correct and I respect that you have spent a bit of time researching this regulation.
All I did was brought up the definition of "Circuit" never once did I say an RCD FCU was a DB or CU so I dont see why it would it need to bound to same constraints ?

I was just looking at Regulation 411.3.4 and your right !! The difference between this regulation and 411.3.3 which covers socket outlets is the part.. "provided for AC final circuits"

Thats why I posted the definition on circuit, it wasnt to be akward or disagree, I was also always taught when putting a FCU on a final circuit then you are changing the characteristics of the addition so the circuit starts from the point where the overcurrent protective device changes, and ive occasionally put a Sw fcu with a 3amp fuse on a rfc to supply a light in a cupboard, as Ive been using logic.

 

[Midwest]

Interesting discussion, I've not got the BBB nor had any training etc on the 18th.

Previously I sort guidance on reg 701.411.3.3, and was advised that the protection of low voltage circuits serving locations (bathrooms etc), would be compliant utilising a local RCD FCU.

Albeit I take spinlondon's point of definition of circuit. However that definition does say '....protected against overcurrent by the same protective device'.

With regard 411.3.4, if I replaced a ceiling rose with a new luminaire, or re-terminated the fixed wiring with a jb of some sort, and extending the wiring with additional cabling, then the existing circuit would now need additional protection at the origin to comply? Or as in this case, additional fixed wiring, would also been at the origin and not locally as above.

I think I would need to seek some guidance on this point. Otherwise in a domestic environment, I could see sparks losing a lot of work, if this is the case.

 

[Beeg]

Thanks for all your replies, much appreciated