On 15/04/2019 08:26, Jeff Layman wrote:

Reading the recent thread about connecting coaxial inside a wall plate,
and how to make sure the coax outer was connected properly, led to
thought about these wall box connections in general.

Basically, why are the components fitted to the removable front plate?
Why aren't they fixed to the back of the box (whether that is fitted on
or in the wall)? It seems to me that as the wiring - and that could be
mains cable or coax - enters through the back of side of the box, it
could be connected directly to a switch, socket, or whatever which would
itself be screwed to the back of the box. The front cover would just
have holes in it to accept the 3-pin socket, coax socket, switch, fuse,
etc, and that would be fixed to the box in the usual manner.

There seem to me several advantages to this. Firstly, you wouldn't need
three hands to hold the box front, cable, and screwdriver at the same
time. Secondly, The cables wouldn't get moved, crushed, or distorted
when the front is screwed on. Thirdly, you could test the connections
without the front of the box being on to make sure it all worked before
screwing the front on.

Having the ability to reposition / rotate the faceplate etc is sometimes
very handy for getting it into a position you can actually see or reach
to wire.

I suspect that main problem however would be the system you describe
would lack the flexibility of the current arrangement - where you can
use the same faceplate with a variety of back box designs to suit the
application (e.g. surface, solid wall, dry lined wall etc).

Also modern building practice will tend to first fix the electricals,
often before the plastering is done. Its bad enough when the plasterer
half fills your metal back box with plaster that you have to clear out
before adding the electrical bit. You would have more of a job trying to
protect a backbox with built in electrical contacts and switch gear etc.


I'm sure I'm missing something here, but can't see it. Ceiling-mounted
pull switches for bathrooms have this arrangement,

Some do, some don't...

and, although not
exactly the same (and now not used much), junction boxes have always had
the connectors fixed to the back of the box, not to the removable front.

In the past there was a fairly common range of MK made surface mount
mains sockets that had everything built into back bit and worked as you
describe. They were in reality often harder to wire since there was less
leeway in the length of wires etc - they had to be exactly right to fit
since there was little scope to fold excess wires back into the back
box. Also you had to wire them before fixing the whole thing to the
wall, which was more cumbersome that just holding the loose face plate
since the whole thing was much larger.



--
Cheers,

John.

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