Re: What can I replace this latching relay system with?

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On 29 Jul 2006 06:43:16 -0700, "Steve Wechsler" <swechsler@xxxxxxxxxxx>
wrote in message  <1154180596.476255.246770@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>:

>
>Marc_F_Hult wrote:
>> One readily available 0-10vdc analog input module that I have used
>> successfully in a commercial installation and have described previously
in
>> comp.home.automation is Crydom's CV2425 that provides variable power
>> ("dimming") with a (maximum rated) 25 amp 120- 240VAC load.
>
>I checked out those Crydom controllers, and geez, they are expensive -
>about $75 a pop. And I'd still need to add a pot at each switch
>location.

OK. Then here's a $60 solution that allows for conventional home
automation.

It is, as best I know, a novel approach  -- leastwise I've never seen it
described before -- that would also satisfy many/most Authorities Having
Jurisdiction (AHJ; aka inspectors) of the US National Electrical Cod (NEC)
Jist this geologist's opinion to be shure ... ;-)

1) Install an INSTEON ICON dimmer ($19.99) at the wall switch location.
Connect the black and white (hot and neutral) of the dimmer to the primary
of a UL listed, low-voltage transformer such as those used for doorbell
installation. They are available for ~$10 at your local Big Box. The red
wire on the dimmer is unused (put a wire nut on it). Connect the secondary
connections of the transformer to two of the low-voltage wires that go to
the ceiling box. Bypass (interconnect ) both primaries to both secondaries
using 0.1 or 0.2ufd  300VAC mylar or other high-frequency, non-polar
capacitor (more on this later). This provides for the INSTEON signal to
get across the transformer which attenuates high frequency.

2) At the ceiling,conventionally connect the ceiling lamp (i.e., the load)
to the AC line using an INSTEON inline dimmer or (essentially the same
thing, except 1/2 the price) an INSTEON ICON dimmer (with the switch plate
removed if you prefer). Also connect a transformer *identical* to the one
at the wall switch to the neutral and hot (Black and white wire) and also
bypass the transformer with two capacitors as with the one at the wall
switch.

3) Set this up using the tap-to-program manner of having one INSTEON
dimmer (the one at the wall switch location) serve as the controller for a
dimmer that controls the load (in the ceiling.

If:

1) your low voltage wire conforms to code to begin with,
2) the transformer produces 50 volts peak or less,
3) your local inspector doesn't balk at the bypass capacitors (these are,
 	after all, used the various UL-listed X-10 filters and couplers
	including X-10 Pro's) and
4) you conventionally mount the transformer (line voltage inside the
j-box; low voltage outside)

you may be OK NEC-wise. (You would need to determine this with your
inspector. My opinion is irrelevant.)

I'll test out this tomorrow. I have all the components in hand.

HTH ... Marc
Marc_F_Hult
www.ECOntrol.org