INSTEON over CAT5; was Re: What can I replace this latching relay system with?

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

In response to a recent comp.home.automation question on how to retrofit
wiring to provide dimmed lighting and (preferably) provide automation to a
house that uses 1950's vintage relay-controlled lighting  (Subject: "What
can I replace this latching relay system with?"), I  bread-boarded a
concept using INSTEON power line control (PLC) devices that I had
previously tested with X-10 but didn't end up using.

The original poster's challenge is that the existing wiring to the wall
switches is suitable only for low voltage and installing new wiring is not
acceptable. The low voltage switches on the wall control latching relays
in the ceiling that switch the AC power to the ceiling-mounted lights. The
AC wiring to the ceiling lights is not individually "home-runned" to the
entrance panel, so centralized dimmers would require re-wiring the AC
wiring which is also not acceptable.

The circuit below solves these issues and provides for both dimming and
home automation control of the lighting using the existing wire
infrastructure.  It transmits powerline control signals and sufficient AC
power to power an INSTEON device for input and signaling purposes only
over the existing low voltage wiring from the AC power and ceiling lamp to
the wall switch.

The wall-mounted INSTEON dimmer(SW1) sends dimming and other signals to
INSTEON dimmer SW2 which in turn controls the light. INSTEON SW2 also
repeats the signal received ensuring that it is available in the AC wiring
throughout the house for conventional home automation control.

I tested this arrangement 'on the bench' using both ~200 feet of CAT5 wire
and ~200 feet of 24-gauge non-twisted telephone wire as the interconnect.
The gauge of the wire needs to be sufficient for the load. Current through
the nominal 24AC control line was about 200mA with an INSTEON ICON switch
(relay) connected for SW1.

One could also control a small load on the isolated INSTEON device by
using sufficiently large transformers and interconnecting wires of
appropriate gauge and installation.


120VAC                   C1                     C3
 Hot  ------+----------+-||-+                 +-||-+
(black )    |          |    |                 |    |  (black)
      INSTEON(red)     +    +-->>------<<-----+    + ---+
       SW2--+ ---+     S || S     low         S || S  INSTEON
            |    |  T1 S || S    voltage   T2 S || S  SW1(red)-Not
            |   Load   S || S    wiring       S || S    | connected
            |    |     |    +--->>-----<<-----+    +----+
AC Neutral--+----+-----+    |                 |    |  (white)
(white)                |    |                 +-||-+
                       +-||-+                  C4
                         C2

Where:

 T1, T2 = UL-listed Class 2, 24volt, 20VA "doorbell" transformers
 C1-C4 = 0.22ufd 250VAC mylar capacitors
 SW1 and SW2 are INSTEON switches or dimmers. SW2 must be suitable for
	the load it controls. There is no load connected to  SW1.

In my bread-boarded test, I used capacitors removed from an X-10 PRO
filter unit where they are used to bypass the inductors.

THIS IS POSTED WITH NO CLAIM AS TO ITS SUITABILITY FOR ANY PARTICULAR
INSTALLATION OR APPLICATION. DANGEROUA VOLATGES ARE PRESENT THAT COULD
PRESENT A SHOCK (ELECTROCUTION) OR FIRE HAZARD. As with all home wiring,
inspection and approval of the authority having jurisdiction is generally
required by local ordinance -- and common sense. In other words, I AM NOT
RESPONSIBLE FOR ANY LIABILITY ARISING FROM ITS USE OR OTHER APPLICATION.

I'll post some pictures later to
www.ECOntrol.org/INSTEON0verCAT5.htm )

HTH ... Marc
Marc_F_Hult
www.ECOntrol.org