Re: Water heater eating X-10 signal

["Mr. Land" <graftonfot@xxxxxxxxx>]

> This really is a fascinating problem.  I never expected that you'd get 5
> bars at the light switch.  I'm thinking that for whatever reason, the signal
> reaching the wall switches is corrupted and that the earlier threads
> regarding interaction between the two phases was correct.  If you live
> near Wash DC, I'd be happy to bring my Monterey analyzer over to see exactly
> what's coming out of the wiring at the switch.  This is one of the few
> instances where an analyzer really trumps an LED bargraph meter since it
> allows for analysis of the actual bits on the powerline as well as the noise
> level in two different parts of the power phase.  My suspicion is that you'd
> see the same sort of readout you see when there are collisions on the line
> from multiple transmitters.
>

A most generous offer, thank you very much!  Unfortunately, I'm pretty
far from DC, but I appreciate it.  I actually have a pretty old dual-
channel scope and an ACT Scope-Test rig I could try to use, but I'm
not sure what I'd be looking for.  I got the Scope Test because I
already had the 'scope, but I've never used it - I could probably be
staring right into a garbled X-10 waveform and not know it.

> From what you've told me, you have the Leviton repeater piggy-backed onto
> existing breakers.  My recollection of the instruction manual (I own one,
> but long ago put it in the "for Ebay" bin) is that they want you to use
> dedicated breakers.  It may only be a code issue, but it could also be a way
> to decrease load interactions with the unit.  I only mention it because we
> are running out of ideas and it's one more thing to try.
>

During some of my testing I did disconnect the Leviton unit in the
panel, then later reconnected it directly to the panel bus stakes,
albeit using alligator clip leads.

> The lack of low voltage feeds to the water heater suggests to me that
> there's a switching power supply capable of running from 240 volts inside
> the unit.  They are a known plague to X-10 and could be the source of the
> noise that Dan has suggested might be the problem.  If so, it might be
> possible to filter only the control circuitry inside the unit, but it
> wouldn't be a very clean fix and it would probably be impossible to get it
> inspected with such a jury rigging.

I'm a little surprised by the suggestion that a water heater would
have a switching power supply in it.  I suppose it's possible -
although it's not immediately obvious to me why you'd need one.  At
any rate, I went to GE's site and downloaded their "Use and Care
Manual", which includes a wiring diagram.  It appears to be a simple
arrangement of thermostatic and limit switches.

>
> From what I've seen of electric heaters, they can have low water sensors,
> overheat sensors and other control circuitry.  If they are generating noise,
> and the HCA-10E is amplifying it, that could easily be the source of your
> problem.  Short of a Monterey or an oscilloscope, I can't think of any good
> ways to test that hypothesis for sure.  What I would expect, if that were
> the case, is that you'd see bars at the switch all the time, whether your
> script was running or not.

Perhaps the noise is there, but the Leviton doesn't see it/care about
it, but once an X-10 signal appears, the Leviton comes alive, does its
repeating/coupling function, and the heater noise piggybacks?  I'm
reaching here, I know.

>
> Dan points out that might not be the case as he's seen wall switches suffer
> from interference that did not register on the ESM1 so without a scope or
> analyzer, it's very hard to say for sure. With that strong a signal, I now
> feel it's some bizarre phase effect of the repeater, and not the low signal
> that I originally thought.
>

I also found an ACT CR-234 in my X-10 "extra parts" bin - I may try
that, too, in place of the Leviton.

> My advice at the point would be to try one of Jeff Volp's XTB II's and yank
> the Leviton.  When I had trouble with mine their tech support rather rudely
> said "We only guarantee it to work with other Decora Home Control devices -
> not X-10 manufactured equipment" to which I replied "Thank you.  I'll be
> sure NEVER to buy another piece of Leviton equipment!"  And I haven't.  Both
> the repeater and the Decora all housecode transmitter are in the same Ebay
> "to be sold" box.  Since then I have purchased a number of the XTB I's and
> have been deliriously happy with them.  I may even eventually buy the XTB II
> as well.

Thanks for that suggestion.

>
> I would report this problem to GE, BTW, just to see what they say.  X-10 and
> Home Depot are both popular enough that it's likely others have hit this
> same wall.  If you pull the model number off the unit's ID plate, I'll even
> send them a note, saying "I was about to buy this GE water heater when I
> read
> about all the troubles this poor guy was having."  I've found "about to buy"
> gets much more attention than "I bought."
>

It'd be interesting to see if they respond - the model is SE50M12AAH.

> --
> Bobby G.

Thanks again!