Bridging Phases

Richard Leonard

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Jan 25, 1996, 3:00:00 AM1/25/96

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I want to extend X-10 control to the 'other side' of my electrical
service. I see there is a device which works on circuit breakers and
jumps the two legs but my supply panel is still fused. Without resorting
to leaving my oven on all the time, and hopefully avoiding hacking some
kind of capacitor across a 240v plug as was recently posted, is there a
commercial product for fuse users? I can run lines from both sides to a
common box if there is a wire-in solution.

Rich Leonard \ Climb Rocks
Boston College \ Wear Clean Socks
LEON...@BCVMCMS.BC.EDU \ (this space available)

Harold Ennulat

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Jan 26, 1996, 3:00:00 AM1/26/96

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Fuses or Circuit Breakers, it makes no difference. The point is that NEC
wants the phase coupler and its wiring protected against short cirucuits.
The "device" you refer to I presume is a phase coupler and will work
with or without Fuses or Breakers. It's a safety issue not a function
issue. Running it across fusses will be no problem.

Opinions expressed herein are my own and may not represent those of 3M.

Actpccpek

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Jan 28, 1996, 3:00:00 AM1/28/96

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In article <4e938q$e...@delphi.bc.edu>, Richard Leonard
<LEON...@bcvmcms.bc.edu> writes:

>I want to extend X-10 control to the 'other side' of my electrical
>service. I see there is a device which works on circuit breakers and
>jumps the two legs but my supply panel is still fused.

You have most likely already seen Harold's reply (henn...@mmm.com, Harold
Ennulat, who also was recently voted as having the cutest sig in the
group) which said that having fuses or ckt breakers makes no difference in
the X-10 coupling aspects of your distribution system. Those little
bursts of 120kHz don't know (or care) if they are traveling through a
circuit breaker or a fuse, its all the same to them.

However, if you are unsure about coupling in 'general', I thought I'd
repeat some old info on basic residential coupling.

Most DIY'ers find that passive coupling is sufficient for the majority of
X-10 installations. Many of the contributors to this group will suggest
using a 0.1mfd capacitor across the legs to allow for signal travel
between the two phases. But remember that the original transmitter only
sends out about 1/3 watt of signal power. As long as most of it is on one
leg, then signal strength remains high on that leg. As soon as a low
impedance pathway in introduced, some of the signal will be reduced on the
source leg. Even though it doesn't make my company a penny, I have to
admit that most of the time it works just fine.

In more complex installations, a capacitor across the two legs will both
help and hurt. DIY'ers have long used this method of providing a low
impedance pathway for X-10 signal to travel from one leg to the other and
it is especially beneficial in situation where only phase-to-neutral
receivers are used, and there is plenty of original signal to go around,
it just needs a way to get from the source leg to the target leg.

It does, however, have 3 drawbacks. First, a capacitor is non-selective.
It will also pass noise. (Admittedly, a minor consideration in 99.99% of
installations.) Secondly, installing a capacitor into your breaker panel
is contrary to National Electric Code. (Also, a minor consideration in
99.99% of installations. We know that if properly rated and properly
installed, its safe. NEC inspectors are often overly rigid.)

Thirdly because passive couplers pass the exact same voltage reference,
phase-to-phase differential signal potential is occasionally cancelled out
completely.

I would prefer that instead of using a capacitor, you use a passive
coupler designed for the job. (Leviton [an evil competitor to us] has
one, but I prefer you buy one of ours.) The ACT part number is CP000.
Also remember that in larger installations, even passive coupling is
inadequate and a true repeater is required. We also make those. For
120/240v split-single phase systems, we build both the r CR240 and CR241.

Hope this helps.

ACT PCC PEK -----> Phillip E. Kingery | Nothing contained herein is
| `--> Powerline Control Components | to be construed as creating
`-> Advanced Control Technologies,Inc | any liability or engineering
Opinions are based on the information | responsibility on behalf of
at hand & worth what you pay for them. | ACT. Fax# 317-337-0200 USA
January 27, 1996
12:00 pm