Re: Water heater eating X-10 signal

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

On Apr 29, 4:06 pm, ddl@danlan.*com (Dan Lanciani) wrote:
> In article <E9ydnWRPweMgFqnbnZ2dnUVZ_rWnn...@xxxxxxx>, ROBERT_GREEN1...@xxxxxxxxx (Robert Green) writes:
>
> | 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.
>
> The problems with this are that (1) such interaction should cause simple
> cancellation rather than corruption per se (unless the repeater is doing
> something really strange like sending out of sync--that particular repeater
> is known to be a bit odd) and (2) with the elements off there would have
> to be a big capacitor leg-to-leg or such and I can't see why that would
> be the case.  The original poster is welcome to try my spare/repaired
> CR230 if he wants to rule out repeater oddness.
>
> | 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.
>
> Traditionally 240V appliances use a 240V transformer for the control
> supply (which is usually 24VAC), but then again traditionally water
> heaters don't have low voltage control circuitry at all.  At this
> point popping the cover of the heater seems in order.
>
> | 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 don't know; I was thinking that that would indeed be the clean fix.
> HVAC folks are always doing quasi-custom hacks to installed equipment
> (some not too neatly) so maybe it isn't a big deal.
>
> | 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.
>
> And in fact it was pretty hard to see even on a scope.  Those switches
> seem to be among the most sensitive X10 receivers.  Given the strong
> signal at the switch it might be worth testing the noise theory by
> connecting a 0.1uF capacitor across one of the switches.  If that makes
> the problem go away it is likely noise, but you can't really leave the
> capacitor there. :)  (You can desensitize the switch as I've described
> elsewhere, but that's a last resort.)
>
>                                 Dan Lanciani
>                                 ddl@danlan.*com

Dan,

What would you think about trying some sort of high pass filtering
from either leg of the 2 pole breaker feeding the heater to ground?

Thank you.