Water heater eating X-10 signal

It's a GE 50 gallon, sold at Home Depot.

I like your idea - connecting the ESM1 at the WS467 - that's my next step.

Thank you very much.

Update:

Borrowed a clamp-around ammeter, observed readings when water heater active, and not, then confirmed inactive and repeated my earlier tests with identical results.

Also, a previous question I'd left unanswered: the ESM1's green X-10 LED is lighting up on the signals.

I have a theoretical question for those of you with a lot of PLC experience: if I plug in some device known to eat X-10 signals, would I expect to see the same drop in signal level at all of the outlets on that phase?

Thanks.

No. Signal sinks tend to be somewhat localized with outlets nearby or downstream most affected.

It's a little late in the game to ask this, but what sort of bulb is in your porchlight? Incandescent? Compact fluorescent?

I recall your saying that the only connections from the water heater to the circuit panel are both "hot" and no neutral. Is there any other connection to the panel from the water heater? Some of the electric water heaters I've seen connect the heating elements to high amperage and high voltage (200+VAC) breakers and the control circuitry to a lower voltage, lower amperage breaker. I assume there's a ground connection to the water heater, too. Is it in good shape?

From what I've read, you've confirmed that when you switch the water heater breaker(breakers?) OFF, you can remotely control the porchlight, but when it's ON, you can't. While this looks like a signed and sealed indictment against the water heater, it may just be that your light switch was at the marginal end of the performance spectrum and thus nearly ANY change in the wiring near that circuit is enough to bleed off what little signal was getting to the porch light switch. That's why I am so interested in the signal level right at the light switch, particularly the numbers you get when the heater breakers are off, versus on.

-- Bobby G.

In article , snipped-for-privacy@whocares.com (Dave Houston) writes: | "Mr. Land" wrote: | | >I have a theoretical question for those of you with a lot of PLC | >experience: if I plug in some device known to eat X-10 signals, would | >I expect to see the same drop in signal level at all of the outlets on | >that phase? | | No. Signal sinks tend to be somewhat localized with outlets nearby or | downstream most affected.

Jeff has suggested that signal sinks can reduce the signal as seen at the panel/repeater (either by taxing the repeater's power supply or by causing a drop across its output coupling network). I've never seen this happen in practice, but it could provide a mechanism for non-local effects.

Dan Lanciani ddl@danlan.*com

XTB-II output with no load is over 40Vpp. The measurements I made here last year with the XTB-II connected to the main distribution panel were 25Vpp on one bus and 30Vpp on the other bus. Since the driver is common, that has to be drop in the coupling networks. One leg must have somewhat lower impedance than the other at 120KHz. The leg that read the lowest was our non-X10 phase with the "unfriendly" loads.

In a recent test, I measured the XTB-II driving 30Vpp into a 5 ohm resistive load. Increasing the load pulls down the 6W unregulated supply. Obviously, more power is delivered as the load impedance decreases. But the lower power supply also decreases the Vpp delivered to the coupling networks.

Jeff

All of our front lights are garden-variety outdoor house lamps (metal frames with various glass panel arrangements, with arrays of 2 or 3

40W "teardrop" shaped incandescent lamps). We have one pair with each mounted on either side of our front door, one pair with each on either side of our garage doors, and a single pole lamp at the end of our driveway near the street. Each pair is controlled by a single WS467, as is the pole lamp. Currently, these are set to X-10 C4, C5 and C6 addresses, although I've tried others out of curiosity and that hasn't helped. They all behave identically: they either all work, or none of them work.

The wire to the water heater is 10/2 WG, so there are the two "hot" wires and a ground - no neutral wire. Yes, the ground connection to the water heater is sound. There are no lower-voltage feeds, control or otherwise, to the heater.

Here's more troubleshooting info:

Through trial and error I identified the breaker which feeds the lights in question. I re-ran my looping test script and used the ESM1 to measure the signal at the screw connection to that breaker. I saw a the 5-bar signal level there, along with the green X-10 light on the ESM1. Next I removed one of the troublesome WS467's (the pole lamp) from the wall near the front door. I disconnected it and tested from ground to each wire there at the box - on the line side wire I saw the same "healthy" 5 bar signal level there. Really confused at this point, I rewired the WS467 into the circuit, and tested again - I still saw the 5 bar signal level! Yet the WS467 does not respond to it.

Could this be some sort of minor garbling and/or ringing that the ESM1 can handle well enough to show a green X-10 indicator, yet be enough to foul up the WS467's? Could two phase wires in the 70-odd feet of

10/2 feeding the heater be causing some sort of weird ringing?

I'm running out of ideas, thanks to you all for continuing to try to assist.

Huh. That's interesting. Obviously I'm no expert, but I would think that the (resistance/impedance) from outlet to outlet would be very low, so that anything sinking X-10 (or 110V, 60Hz for that matter) would be experienced at all the outlets on that circuit.

I'm not arguing, just a bit surprised.

Thank you.

| Through trial and error I identified the breaker which feeds the | lights in question. I re-ran my looping test script and used the ESM1 | to measure the signal at the screw connection to that breaker. I saw | a the 5-bar signal level there, along with the green X-10 light on the | ESM1. Next I removed one of the troublesome WS467's (the pole lamp) | from the wall near the front door. I disconnected it and tested from | ground to each wire there at the box - on the line side wire I saw the | same "healthy" 5 bar signal level there. Really confused at this | point, I rewired the WS467 into the circuit, and tested again - I | still saw the 5 bar signal level! Yet the WS467 does not respond to | it.

Sounds more and more like a noise problem. Perhaps it's time to look at the control circuit for the water heater. It might have some "helpful" electronics...

| Could this be some sort of minor garbling and/or ringing that the ESM1 | can handle well enough to show a green X-10 indicator, yet be enough | to foul up the WS467's? Could two phase wires in the 70-odd feet of | 10/2 feeding the heater be causing some sort of weird ringing?

The WS467 has a very sensitive receiver and you can get some surprisingly complicated transmission line effects in the wiring network, but I'd keep looking for simpler explanations for a while. I know from personal experience that the ESM1 will not show noise that can incapacitate a WS467.

Dan Lanciani ddl@danlan.*com

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.

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.

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.

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.

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.

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.

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."

-- Bobby G.

I agree that it's likely noise. The ESM1 also doesn't do anything sophisticated for the "X10 Good" indicator. Paul Beam, who designed it, told me he just looked to see if there were the expected number of 1 and 0 bits following 1110. I'm not sure whether it even rejects sequences like 1100 but did not ask that specifically.

The gain bandwidth product of the opamp used in the ESM1 is not very high which limits its response to higher frequencies.

I tried, unsuccessfully, to find specs on newer GE water heaters. If there are any electronics, the lack of a neutral suggests that they use a switch mode power supply connected phase-to-phase.

Electrical power distribution does provide low impedance for 60Hz. However, up at 120KHz things are a bit different. Wire inductance and distributed capacitance comes into play. There is normally a steady decrease in signal strength as the distance from the breaker panel increases. Any "signal sucker" will ramp the signal down more quickly on its circuit, and all receptacles past that device will have a correspondingly lower signal level.

In addition to the steady decrease in signal strength as it moves away from the panel, there can also be nodes and peaks if inductance and capacitance just happen to hit a resonant point. I believe that causes the "black holes" that appear at certain locations.

Jeff

| 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

So what is the best way to see the noise on a scope?

Hook the scope to an X10 bridge to filter the 60Hz and make the X10 signal and noise easier to see?

It would be hard to see the noise riding on a 120V signal without blowing out the input on the scope.

It depends on the noise. X-10 bridges and ACT's ScopeTest2 are also tuned circuits that may filter out the noise.

One other option is just an RC circuit like the one in Appendix C of Microchip's appnote AN236 but even with that I could never see what my old NEC monitor vwas putting out that gave Smarthome (but not X-10 made) modules a fit.

In article , snipped-for-privacy@spamfree.net (lnh) writes: | In article , | ddl@danlan.*com (Dan Lanciani) wrote: | | > In article , | > ROBERT snipped-for-privacy@YAH00.COM (Robert Green) writes: | > | > | > | 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. | | So what is the best way to see the noise on a scope? | | Hook the scope to an X10 bridge to filter the 60Hz and make the X10 | signal and noise easier to see?

You could do that, but if the bridge (coupler) is too good (too selective) you might not see the noise. You could also use a commercial product, e.g., ACT's Scope-Test[2]. I use a series 0.1uF capacitor and 0.25A fuse to hot with a 100 ohm resistor across the scope's input. I believe this is mostly similar to some of the commercial products; the fuse gives me a little extra feeling of safety...

Dan Lanciani ddl@danlan.*com

I didn't intend for "interaction between the phases" to exclude any funny business from the Leviton repeater. (-: It's still a primary culprit and why I just ordered an XTB II from Jeff. Even though the XTBs have worked flawlessly, I really *do* need a repeater for controllers that can't be routed through an XTB. But I need one that works for my particular usage pattern and equipment inventory. That wasn't the Leviton. I'm hoping it

*will* be the XTB-II.

It was a long time ago, but IIRC, the most irksome issue was the constant locking up and resetting involved. The X-10 floodlights seemed to be the culprit but I never ran it to ground. Each lockup caused a significant drop in SAF for X-10, so I went the multiple transceiver route, with its many perils but fewer trips to the circuit panel overall. That's very generous of you to offer your spare for testing.

I suppose it would end the speculation, at least. When I was looking for GE specific water heater schematics I did see some newer (tankless, I believe) units that had switch mode power supplies. It's getting harder and harder to find traditional transformer-based low voltage power supplies. The latest batch of cameras I got had tiny 500mA 12VDC SM power supplies that appeared to be X-10 friendly so I am going to order some more to replace the large transformer-based 500mA I'm using now. In any event, powering a switch mode supply from two hot legs is probably something we've not seen much of - yet. Transformers were the industry standard. I suspect we'll be seeing a lot more SM power supplies in strange places as the push to reduce carbon emissions gains momentum.

After I wrote that and sent it, I realized "impossible" was too strong a word, even modified by "probably." The actuality is that if there's enough room in the control hatch, no inspector would ever be likely to see it.

If I had spent all weekend trying to get the porchlights back on, I might be tempted to hardwire it into a box.

The more I think about it, the more I think it's noise from a switch mode PS being fed into the Leviton repeater in a way that the designers never intended. It would be *so* nice to see what the Monterey reads at the wall switch in noise, analysis and signal dissect modes. Signal dissect would be able to read the voltage level of each bit and that usually tells you, at least in collisions, which units are colliding.

At some point we should be able to learn what's inside the GE unit, either from Mr. Land or some GE instruction manual. I might even go to Home Depot to see for myself. Gotta take my N-vision CFL floodlight back, anyway. It began taking longer and longer to warm up and now it never warms up completely. Too bad. It was X-10 AND current sense friendly, too.

-- Bobby G.

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.

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.

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.

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.

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

Thanks for that suggestion.

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

Thanks again!

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.