RCD protection for added lighting points

[JamieP]

So most people seem to say that if you add a lighting point it doesn't require RCD protection

2.6.3.4 Exception 2 Extensions to final subcircuits supplying lighting points only, provided
that the existing final subcircuit is not RCD-protected.

But looking at this the final subcircuit must contain lighting points only

So adding a lighting point to a circuit with anything else other than lighting points on it means RCD protection is still required correct?


This leads me to a following question, clause 2.6.3.1 has a note that says "NOTE: For the purpose of this Clause, combination fan, light and heater
units, smoke detectors, exhaust fans and ceiling sweep fans are all regarded
as lighting points" under 2.6.3.4, do you count these points as lighting points as well? Or is it as the note says, only applies to "this clause" which is 2.6.3.1?

[gregmcc]

Regard them all as lighting points. when reading the standard just picking a section like ".....lighting points only" and ignoring inclusions that clearly says other items are classed as lighting point is not the way to go.

So yes you do count these as lighting points.

With a lot of new downlights they are on a plug, putting a socket on the light circuit straight away triggers the must have an RCD, the way around this would be to cut the plug off and put up a J-Box

[DougP]

@Jamie - the exception to 2.6.3.4 states that: "The requirements of Clauses 2.6.3.1 and 2.6.3.2 need not apply to the following:" so the "for the purpose of this clause.." in 2.6.3.1 means that the exception 3 in 2.6.3.4 applies to those points as well. So at the moment you can install a light fan unit and not provide RCD protection if you don't want to.

But you won't have to worry about it at some point in the future, as the exception for extensions to lighting points only has been removed for NZ in 3000:2018

[JamieP]

Ah, I had missed the "The requirements of Clauses 2.6.3.1 and 2.6.3.2 need not
apply to the following" that's fine, that clears up my second question

But what about the first? Lighting points don't need to comply with 2.6.3.1 and 2.6.3.2 when they are added to a circuit that supplies lighting points only

Does this mean if a "lighting point" is added to a circuit for socket-outlets that this lighting point would then need RCD protection due to not being added to a circuit of lightning points only?

[gregmcc]

Thats a good question, never come across that before, sorry dont have an answer

[AlecK]

There are 2 issues here; complicated due to the way the subclauses within 2.6.3 have changed over time. and also due to failure to take note of the words in the intro to each part.

First issue is that which clause applies depends in what you are doing.

Both 2.6.3.1 and 2.6.3.2 ONLY make rules for RCD protection of '"final subcircuits".
"final subcircuit" is a defined term [1.4.88]; and as a result if you're not installing a new, complete, "final subcircuit" (as defined) these clauses have zero effect.

That note in 2.6.3.1 ONLY applies to "this clause"; ie 2.6.3.1; and the purpose was / is to avoid installers saying "it's a fan only, , no light(s) on this new FS, so I don't need an RCD". Obviously a FS supplying lights plus other items is supplying lights; so gets RCD regardless of what the 'other" items may be.

2.6.3.4 covers ALL "adds & alts", regardless of location.
If you add a light, there's nothing in this clause to require an RCD
But if you add a socket, then - as Greg said - there IS a rule that requires RCD protection - but only of the new socket, not of the entire subcircuit.


Second issue is that unfortunately confusion has been caused by the wording(s) of various incarnations of the exceptions at the end 9oe after 2.6.3.4).
Originally they were exceptions to ALL of 2.06.3; but that wasn't as obvious as it should have been;, and many readers believed they applied only to 2.6.3.4 (adds 7 alts). That includes some of the people who wrote the various amendments to them.
The result was, over several versions, a very confusing hotch-potch; which eventually got tided up in A2 to 2007 edition.

That wording makes clear that these exceptions are to both 2.6.3.1 7 2.6.3.2; and so they have NO effect on 2.6.3.4.
NONE of them actually do anything that isn't already done by the fact that both 2.6.3.1 7 2.6.3.2 limit themselves to complete, new, FSs; and can't affect ANY of the sorts of work listed in the exceptions. But when even many of the writers don't understand that basic point, we can't expect other readers to get it either; and clarifying doesn't do any great harm.
The alternative would have been to have these Exceptions moved from end-of-2.6.3; and copied-in after each of 2.6.3.1 & 2.6.3.2.

As a result; regardless of what sort of installation you're dealing with; there are only 2 cases where RCD protection is required for anything that isn't a new, complete, FS:
- replacement of all overcurrent protection on a switchboard
- adding a socket to (any sort of) existing FS. This includes sockets added to non-domestic - but most people simply haven't understood that, and it was never the intent either.

It all gets much better in 2018 edition; with each of the 4 sub-clauses having the Exceptions that apply to it located immediately after it.
In particular, there will be 2 Exceptions to 2.6.3.34 (adds-&-alts).

WRT sockets for luminaires to plug into; both Oz & NZ have always treated them as sockets. But then along came domestic downlights pre-fitted with plugs, and arguments about whether the (typically) surface sockets should be seen as lighting points instead (so no RCD because "I only added a light"). Expect the Australian clause to change in A2, with a new Exception. But whatever changes happen there; I believe NZ will probably continue to treat sockets intended for luminaires as sockets.

[JamieP]

Thanks Alec, very informative as usual

In regards to your last paragraph the way I've always seen it is as you suggest, a socket out, is a socket out and must meet such rules

In the case of lightning as suggested, I always saw it as the socket outlet actually being where the installation wiring ended and always regarded them as socket outlets first and foremost