Re: Water heater eating X-10 signal

[graftonfot@xxxxxxxxx]

On Apr 25, 12:56 am, ddl@danlan.*com (Dan Lanciani) wrote:
> In article <1177470203.376066.127...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, grafton...@xxxxxxxxx writes:
>
> | Sorry for the delay, finally got time to do a little data gathering on
> | this issue.
> |
> | I find my measurement results a bit confusing.
> |
> | In my breaker panel I have a Leviton HCA02-10E coupler/repeater.  It's
> | wired via an existing 2-pole 30A breaker feeding a dryer, and was part
> | of my working configuration before this problem started.
> |
> | To do some measurements, I wrote a small HomeSeer script consisting of
> | a loop which sends "B1" "ON", waits 3 seconds, sends "B1" "OFF", waits
> | another 3 seconds, then repeats.
> |
> | With this script running I measured signal levels in the breaker panel
> | using an ESM-1 connected via alligator clip leads.
>
> Where did you connect the clips in the panel?

I connected one lead to the neutral bus bar, then alternated the other
lead between the phase buses (the metal tabs that the breakers stake
onto.)

>
> | Here are my (somewhat puzzling) results.  I've arbitrarily labeled the
> | phases "A" and "B", and expressed the observed signal strengths in
> | terms of number of bars lit on the ESM-1:
> |
> | Condition: HCA02 breaker OFF, water heater breaker OFF
> |     Phase A: approx 1.5 bars
> |     Phase B: 0 bars
> |
> | Condition HCA02 breaker OFF, water heater breaker ON
> |     Phase A: approx 1.5 bars
> |     Phase B: 0 bars
> |
> | Condition HCA02 breaker ON, water heater breaker OFF
> |     Phase A: 5 bars
> |     Phase B: 4 bars
> |
> | Condition HCA02 breaker ON, water heater breaker ON
> |     Phase A: 5 bars
> |     Phase B: 4 bars
> |
> | Apparently the HCA02 is performing its repeater function quite well.
> | But what's puzzling is that with the coupler in-circuit, closing the
> | breaker for the water heater apparently has no visible effect on the
> | signal coupling as shown by the ESM-1 at the breaker panel, even
> | though I've repeatedly confirmed that it debilitates my control of my
> | front yard lighting.
> |
> | Shouldn't I expect to see a big drop in Phase B signal with the water
> | heater circuit connected?
>
> Are you sure that one or both elements in the water heater come(s) on when
> you enable its breaker?  Alternately, do you know that the yard lighting
> control is debilitated even when no elements are on?  Or maybe simplest of
> all:  were you checking that the yard lighting control came and went as you
> closed and opened the breaker during your above tests?
>
>                                 Dan Lanciani

Actually, I'm more sure that the elements *aren't* on for all these
tests.  I'll need to figure out a reasonable way to confirm this,
though (I don't have a clamp-on ammeter.)

All of the phenomena/tests I've described have occurred during times
of no water usage.  I realize this doesn't absolutely guarantee that
one of the heater's elements is not in-circuit during the test, but it
makes it much more unlikely.  As I said I'll try to confirm this.

I'm not familiar with water heater circuitry - are they as simply as
an SPST switch controlled by a heat sensor?  I'm wondering if they
typically include some sort of spark-suppression RC stuff to preserve
the thermostat contacts...perhaps that's doing something weird to the
X-10 signals.

Thanks for the continued suggestions...