On 01/10/2018 21:31, Scott wrote:
On Mon, 1 Oct 2018 21:03:57 +0100, ARW
wrote:

On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

Perhaps a better comparison with socket circuits in general rather than
a ring specifically. Then there are several ways of doing the sockets.
However socket circuits are inherently similar in that they don't
usually involve remote switching (save for a few under counter sockets
in the kitchen), or a remote load from the main termination (although
you could argue a spur is such a thing).



--
Cheers,

John.

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