Re: New technology wall switch dimmers?

[Charles Sullivan <cwsulliv@xxxxxxxxxxxx>]

On Sun, 19 Feb 2006 19:40:36 -0500, none wrote:

> "Charles Sullivan" <cwsulliv@xxxxxxxxxxxx> wrote in message
> news:pan.2006.02.19.17.29.22.300242@xxxxxxxxxxxxxxx
>> There has been a lot of discussion here recently about newer
>> HA technologies (Insteon, ZigBee, Z-wave, etc) replacing X10.
>>
>> Which, if any, of these newer technologies offer (or have the
>> capability of offering) wall switch dimmers which don't require
>> a neutral wire in the switch box?
>>
>> Plug-in dimmers are fine, but I have many more (X10) wall switch
>> dimmers installed in my house.  As far as I can recall, none of
>> the switch boxes have a neutral wire and it would be prohibitively
>> expensive to have them rewired.  And I suspect that the switch
>> boxes in most houses don't have a neutral wire.
>>
>> It seems to me that any HA technology which doesn't or can't offer
>> wall switches that work without a neutral won't get very far,
>> except possibly when pre-planned for in new construction.
>
> You are greatly underestimating the number of homes with neutral wires.
>
> While I could not find an exact date for when the NEC required neutral wires
> what I did find says it is common for homes after 1965 to have a neutral
> wire at the switch box. How many millions of homes have been built since
> 1965?

Whether or not it may be in the NEC, such a requirement isn't
included in the local electrical codes of two cities I checked
(Greensboro, NC and Plano, TX) according to their chief code
enforcement officers.  Are you perhaps thinking of the ground
wire?

A Greensboro electrical contractor tells me that if wiring from
below, his practise is to run the cable from the breaker panel to
the switch box and thence up to the light fixture, so in that
case there would be a neutral connection available. But if wiring
from above, the cable from the breaker panel goes to the light
fixture and a 2-wire (+ ground) cable is dropped to the switch box.

In Greensboro usual residential construction is such that most
wiring is done from below (basement or crawl space) and his
estimate is that around 90% of newer houses would in fact have the
neutral connection.  So in this locality you would be correct.

However in Texas, most houses are built on a slab and wired from
the attic.  The 1978-vintage slab ranch I lived in there had only
the 2-wire (+ ground) in the switch boxes.  It's unlikely most others
in the area were any different.

> If you're unwilling to upgrade your old wiring (which is not that hard or
> expensive, rewiring has been going on for decades, there are many tools and
> techniques developed just for the purpose), then there will always be the
> old X10 switches that are compatible with 2 wire wiring. There are many
> reasons the newer stuff requires a neutral wire and always will. (And one of
> those reasons is that there is actually very little demand for 2 wire
> automated switches)

While it would have been very simple to upgrade the switch wiring
in the Plano ranch, any electrical rewiring in my present (older)
residence is a major undertaking.

> You sound like a guy who's upset the latest software won't run on his old
> 386 PC with windows 3.1.

Is that statement somehow relevant to the topic under discussion or
just your notion of a gratuitous insult?

Regards,
Charles Sullivan