Need help with PLC noise problems in a Manhattan (New York City) apartment

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Hi there. I've been having ongoing noise issues with my new apartment and our lights go on and off at random. After testing for three months and trying several different noise filters, I don't yet have the results I need. Time to ask around for help.

Also, all the installers I can find in my "area" are actually not in Manhattan but in other boros or Northern New Jersey, where single-family homes are more prevalent than apartment buildings.

Here's what I know:

1) My apartment building isn't huge - only about 50 apartments (8 or 9 on each of six floors)

2) My apartment is actually TWO apartments combined (let's call them 2B and 2C) with the wall between them knocked down. But we have two separate breaker panels, each on a separate electric meter, each servicing half the apartment.

3) I have learned, unfortunately, that I am far more knowledgeable about X10/DHC than my general contractor's licensed electrician is (or cares to be).

4) Using a Smarthome Testerlinc meter, I can determine that I have 121kHz noise coming in from outside my apartments because I can meter 120kHz activity, and bad codes, while all our circuits breakers in both panels are switched off (except for the breaker feeding this meter).

5) The master shut-off breakers in the basement (two per apartment; we have single split-phase wiring) are grouped together in sets of 5 apartments, as follows (you may need to switch to a fixed-width font):

______________________ ______________________ | | | | | | | | | (MASTER BREAKERS) | | (MASTER BREAKERS) | | | | | | |----| |----| | | |----| |----| | | 6A | | | | | | 6A | | 5B | | | | | | 5B | | |----| |----| | | |----| |----| | | | | | | |----| |----| | | |----| |----| | | 1B | | | | | | 1B | | 6B | | | | | | 6B | | |----| |----| | | |----| |----| | | | | | | |----| |----| | | |----| |----| | | 2B | | | | | | 2B | | 1C | | | | | | 1C | | |----| |----| | | |----| |----| | | | | | | |----| |----| | | |----| |----| | | 3B | | | | | | 3B | | 2C | | | | | | 2C | | |----| |----| | | |----| |----| | | | | | | |----| |----| | | |----| |----| | | 4B | | | | | | 4B | | 3C | | | | | | 3C | | |----| |----| | | |----| |----| | | | | | | | | | ------------------------ ------------------------

So my 2B apartment shares a common neutral with apartments 6A, 1B, 3B, and 4B, while my 2C apartment shares a common neutral with 5B, 6B, 1C and 3C.

6) This make some sense given our results: although I have noise coming in from other apartments or elsewhere in the neighborhood, the noise levels differ on each phase of each service panel. My assumption is that 2B is seeing noise generated mostly by 6A through 4B and that 2C is seeing noise generated mostly by 5B through 3C.

7) For what it's worth: the 2B master shutoff breakers are 50 amps and the 2C master shutoff breakers are 40 amps.

That describes the environment. Now for our filtering attempts:

At first we tried installing PZZ01 filters in the 2B and 2C service panels, with some success but not enough: noise levels and random lighting malfunctions were reduced but still present. Also, controller signals generated on a 2C line were still able to operate devices on the 2B panel, suggesting that these filters aren't powerful enough for my application. (Not that I want to use two separate controllers in one home, but that's the nature of the beast. I don't want a downstairs neighbor controlling my lights, either.)

I now have Leviton 6285 signal attenuators installed at each service panel, with greater success. We've had some lights flicker on in the 2 days since installation, but none flicker off. There seems to be good isolation between the two service panels. I have not yet installed Leviton HCA02-10E signal amplifiers, but I'm not sure we'll need them: my ActiveHome Pro controller usually works well, while noise levels are usually quiet. But I'm metering

1 - 2 hours each night with high noise levels and the ActiveHome Pro signals can't get through (like the old paradigm of whispering in a crowded restaurant).

Here's the weird part: during these high noise periods, the Leviton 6285 seems to be AMPLIFYING the noise, not attenuating it. When I switch its breakers off, the noise level drops.

During the other 14 or so hours of the waking day, the 6285 is indeed reducing noise levels: when we switch the breakers off, the noise level jumps, as we would expect.

Also add to the mix: last night I discovered that one item in the apartment -- an old PC monitor -- is indeed adding noise at random times to the system, whether it's on, off or in standby. I pulled its plug.

My questions for the group:

1) Are there known situations or environments when a Leviton 6285 can boost noise rather than attenuate it? Is it ever known to be flaky like this (suggesting I have a bad unit), or is this an indication that I didn't install it properly?

2) Is the Leviton HCA02-10E likely to fix this? I would think not: while an amplified controller code could blast through some noise, the noise itself could trigger device malfunctions. Or does the HCA02-10E also attenuate noise?

3) Should the Leviton 6285 attenuate the noise generated by the old computer monitor along with the noise coming in from outside the apartment, or will I need a separate plug-in filter in addition?

4) Is there a better way of addressing my noise problems?

Best wishes to all for a happy Thanksgiving weekend!

-- Alan

It could also suggest that there's a major screwup in the apartment wiring. I've found that the older a building and the more remodeling it's seen, the more likely this is the case. If the cross-linking involves you in the electrical "networks" of several other tenants, you'll likely NEVER be able to control a normal PLC installation to your satisfaction. You could be plunged into a powerline nightmare whenever another tenant gets a new laptop, UPS, shaver, battery charger, CFL, dimmer, etc.

If I were in your shoes, I would look to an RF solution that didn't care a whit how dirty the powerline was. We've recently seen a "2 apartments combined" scenario stump our resident X-10 expert, who was armed with both an oscilloscope and a million man-ours of X-10 experience. That doesn't bode well for you.

X-10 wise, you may have no other choice in an environment like yours, and dual controllers induce all sorts of other problems that are difficult to track down. I love X-10. In a stand-alone house with low tech neighbors, it works just fine for me. In an environment where the basic house wiring has "morphed" the way yours has (apartments merged) and where one is likely to have neighbors into technical things that can "dirty" the powerline, I would look into one of the new wireless mesh networks like Zigbee. X-10 is decades old. The designers just couldn't foretell how much things would change in 20+ years.

I don't know how much you spent on the basics and how much you've spent trying to get it to work, but for me at about $1,000 I would throw in the X-10 towel completely. You can't possibly keep your environment clean unless you generate your own power and disconnect from the grid. Unless you're thrilled at the possibility of your X-10 system being knocked out every time a neighbor buys a new gizmo, you may wish to consider other topologies.

What kind of lights? Does the "flickering on" come shortly after they've just been turned off?

Don't bet your life on it. Experienced sparkies treat comboed apartments the way experienced cops approach domestic disputes. With great care. I'd bet $20 that within an hour, armed only with a 3-wire plug in tester, I could find places where two circuits are crossed. Sometimes it's only so that the hall light switch can control lamps on both sides of the new, single large apartment. Sometimes someone needs a neutral wire at a switch leg and grabs one from another circuit. The older the building, the more likely someone's done something non-standard.

I am not sure you can install two of those in a single installation without serious problems. Better check with Leviton.

As I said, there's no guarantee you're truly isolated from your neighbors, even with filters installed. If you see these noise levels during prime time, it's likely someone's got an expensive toy that's souring the powerline. It would be pretty unfriendly to demand he filter or remove it. Consider how many new high tech toys are likely to be added to your building power grid this Christmas alone and you may want to seriously rethink X-10.

Huh? Drops where? If you turn it off, all circuits it was filtering should be dead. Where are you plugging your meter in?

Without extensive signal tracing, it's very hard to locate a miswired appliance that's been using that neutral instead of the correct one finds another path to neutral through some incredible cluster of miswired switches. Items that effect X-10 also interact with each other. My gut tells me there's something very weird with your wiring.

How are you measuring the noise level? When you switch the breakers off, the meter should die with them. Where is the noise level jumping when you turn the breakers off?

Given that almost everyone has an X-10 killer somewhere and that your wiring seems less than perfect, I'd go RF since pulling CAT5 to each load (the preferred solution in noisy environments) is probably very hard in your case. A good RF mesh network wouldn't care if you had 1000 old PCs nor would it care if each outlet in your apartment came from a different breaker.

Tell us how you know it's boosting noise and we might be able to explain. A panel filter should filter all outlets and switched connected downstream. When you shut it off, you kill those outlets unless you've wired a shunt that pulls the 6285 completely out of the circuit.

I'd say it would only make your problems worse.

The old monitor probably isn't noisy - it probably "sucks" the X-10 signals up. They are two different sorts of problems although a filter can often cure either. The answer to your question is "yes, you will need a separate plug-in filter for every X-10 unfriendly device in your house." Think of the breaker mounted filters as firewalls. They stop outside noise from getting into your apartment's power grid. They stop your noisy (or signal sucking) old monitors from affecting your *neighbors* X-10 system. They do NOT stop any locally generated problems like your PC monitor from affecting the rest of your system.

ZigBee. It's a wireless mesh network in which each device hears and repeats commands. It has an enormously higher data rate than X-10 and is nearly immune to powerline quality issues.

Realistically, you could be just a few plug in filters away from fairly reliable operation. You need to go to the breakers and take measurements of the propagated X-10 signal at various points in the apartment and then do it again while disabling each breaker in turn. Eventually, you'll turn a breaker off and the X-10 signal will rise by almost a volt. Somewhere on that circuit is a signal sucker or noise generator.

I'd also be checking each circuit for leak current when its breaker was killed. In a case like yours I would also make a table of every outlet and light switch and appliance and make sure I knew which breaker controlled each and every one of them.

-- Bobby G.

An inventory of your X-10 modules/switches might be helpful. X-10 transmitters such as your CM15A, any two-way devices and any other "tranceivers (e.g. RR501, TM751) are of particular interest.

In a brief search I was unable to find out much about the 6285 signal attenuator but I doubt that it can amplify. None of the literature I found on it gives a figure for how much it attenuates.

You use the phrase "noise level" but I don't see any reference to anything that can actually measure signal or noise levels. The TesterLinc manual indicates that it does not measure a level but only counts cycles within some (unspecified) window. What quality counts do you see if you use the CM15A to send PLC during relatively noise-free times? What quality counts do you see during high noise times (without sending anything yourself)?

The TesterLinc also has a much narrower bandwidth (110-140kHz) than the typical X-10 receiver although that doesn't appear to be a factor here.

What housecodes does the CM15A transceive? You will need a plug-in filter for the noisy monitor - the 6285 only blocks signal or noise from passing in or out of your apartment's wiring.

Has the building always contained apartments or has it been converted from commercial use?

I'd love to know how >Hi there. I've been having ongoing noise issues with my new

Any RF system is likely to be problematic in a densely inhabited urban environment.

My mystery signal disappeared after be>If I were in your shoes, I would look to an RF solution that didn't care a

If you are fully insulated from "external" noise or unsollicited X10 (neightbour RF or PLC), I discovered in my case that most of my noise problem are coming from fluorescent bulb.

Like already explained, I'm talking about interference meaning that one specific X10 command become an unpredictable result (issuing D10 ON, result is D10 ON and D12 OFF at the same time). Sometime X10 device are triggered without any issued X10 command (often lamp module).

These kind of strange behaviour is not detectable by computer interface or dumpable through PC software.

Most of the time, "uncontrollable device" are basic X10 type (LM465, AM..), but it's not systematic (less often Smarthome or ADS could be hit).

After hours trying to guess what really happens with a digital oscilloscope, I have the following feeling (I'm not a pro, just an enthusiast) :

- Fluorescent bulb generate at zero crossing a current spike around

0.3V.

- This spike doesn't seems to be 120khz but are not filtered by LM465 electronic (as a consequence, spike is 'readable" on chip pin 1. In specific condition (were the signal parasite match with X10 command, the original command is tampered by fluorescent bulb spike".

-by the fact that spike are "low current", they are unable to be spread on whole installation (attenuation will kill il before reaching distribution panel).

On the basis of my test, I believe that basic X10 module doesn't "stricto sensu" follow X10 protocol for the following reasons :

- they are not waiting the expected delay with 120khz on the line to consider the signal valid (spike is enough to be considered valid).

-they are not matching the first and second copy of the X10 command (only one is analysed and interpreted). In one of my room, two module on the same address are triggered with a delay between the two. My explanation is, the first one is on "good line" the second on a line which require "signal repeater" to be listenable. First is directly triggered on the first copy of X10, second is triggered by the signal repeater amplified command with small delay.

It's very difficult to provide solution (excluding removing all Fluorescent bulb). Just few good practice :

- Plug your "X10 sending" device on a dedicate line directly wired to the distribution panel.

- If it happens with one fluorescent bulb brand, try another one. On basis of scope analysis, they are all noisy but some are producing twice time bigger interference than others.

- replace "basic X10" by more reliable.

Hope it helps (happy to be back "on the X10 battlefield",discovered that my new ISP is not forwarding my replies on usenet since 6 month).

Thierry

Dave Houst> Any RF system is likely to be problematic in a densely inhabited urban > environment.

X-10 has documented that spikes can directly cause some devices to operate.

Steven Bloom has a 'fix' for certain switches.

Some modules are less susceptible than others. I had problems with a screw-in module (the older dimmable one) turning off when I turned a flurescent light off. I replaced the screw-in module with an LM14A and npo longer have the problem.

However, it's unlikely that such switch>If you are fully insulated from "external" noise or unsollicited X10

Thank you all for your guidance. To answer some questions/comments:

1) I'm not an electrician or electrical engineer, but I am an audio visual engineer working in Manhattan for 20+ years now. My gut feeling when I saw Robert Green's RF recommendation is that in this city I don't trust wireless *anything* -- too many glitches in both old, tested technologies (wireless microphones) to new ones (Nextel GPRS) . We just have too much traffic to keep a local RF system reliable.

I thank Dave Houston for concurring on that, but he asks about Insteon. Isn't Insteon half RF- based? That's why I opted for a more "tried and true" X10 solution; we even tested an X10 dimmer in our old apartment four blocks away in the same neighborhood and had flawless results for two months. I've since learned the hard way that the two buildings are not analogous. :-(

The other point about Insteon, I think, is that it continues sending a command until the receiving device acknowledges it. That might mean that during a long noisy period we could see the command execute a few hours after it was given. But I'm speculating here; I have no hands-on experience with Insteon.

2) I simplified the description of my apartment's environment in my last post ("That was SIMPLE, Alan???") It's not just two adjoining apartments with a wall knocked down but in fact underwent a gut renovation. Every old branch circuit was severed, new lines were run through new walls, with new switches, outlets, etc., and one of the service panels was upgraded. I think the mains wiring from the basement cutoff breakers may date from 1941 but I doubt it; the feeder cable seems to be PVC insulated.

So if we are cross-linked with any neighbors, this would happen before service reaches our apartment, as all our branch circuit wiring is new.

But if we are indeed cross-linked with our neighbors before the service enters our panels, wouldn't a whole-house block or attenuator stop or greatly reduce that? Otherwise, what purpose do those devices serve???

3) When I speak of our lights randomly flickering on or off (I chose the wrong word; they don't "flicker" but do switch on or off); I did mean RANDOM: there is no recognizable time or pattern, i.e., they don't turn off right after going on, or vice versa. It just happens when it happens; most of the time I can run over to the TesterLinc and see high 120kHz activity but no valid X10 codes (lots of bad blocks, though).

4) When I wrote of "good isolation" between our two service panels, I used the signal generated by our Active Home Pro (CM15A) and the TesterLinc meter: without the attenuators now in place, signals generated on one phase of one service panel could be detected by devices on both phases of both service panels. This was the case even with a PZZ01 installed in each panel.

But with the 6285 installed, I could not operate devices or meter anything on the other panel from the one the CM15A was plugged into. We tested both panels that way, and they do appear to be isolated from each other.

5) My method of measuring noise levels: using Mode 4 of the TesterLinc ("120kHz Activity"), I can see Quality Counts of around 50, or 80, or 120 at various noisy times. This usually does not change as I switch branch breakers off. The one time I saw the Quality Count drop when I switched off a branch circuit, I checked everything plugged into the branch. That's how I found the noisy PC monitor the other night.

I plug the meter into an outlet with no other resistors (appliances, x10 devices, etc) on that branch. Of course, when I shut that breaker, the meter goes dead. But there is nothing else on that branch that would generate any signal or noise.

As per my electrician's and my understanding of Leviton's written instructions, the filter is installed on a separate pair of 15 amp circuit breakers. So when I switch the filter "off", the other branches stay on, including the TesterLinc's meter, but the filter's branches (one for each phase) are switched off. During relatively quiet times, the Quality Count may jump from 000 or 001 to the 20s, 30s or higher when I switch the filter off. That's how it's supposed to work. But during peak noisy times, switching off the breakers feeding the 6285 cuts the Quality Count from around 120 down to around 60. That's opposite of how it's supposed to work.

But based on feedback I'm getting from Robert Green and Dave Houston, I suspect I don't have my 6285s installed properly. (See below, very bottom of this post.)

6) My only controller device at this time is the CM15A. When it transmits codes, I see Quality Counts of around 50 - 60. That's at the low end of the Quality Count during our noisy evenings, as I mentioned above (count can be from the 50s to the 120s).

All of my dimmers are X10 RSW17 or companion RSW19 slave switches. No other modules at this time, but if this goes well I will add 2 or 3 plug-in dimmers -- all for incandescent lights (no fluorescents, CFLs, halogen low voltage transformers, etc.)

We are at this time transceiving only House Code L. We switched from House Code G within the first week of our problems, before we bought the tester and started serious troubleshooting.

7) Regarding using multiple HCA02-10E amplifiers in a single home: Leviton in fact specifies that if there are sub-panels, an amplifier is required at each one. So I don't think that separate HCA02-10Es at each of two main panels would be a problem, but I'm not spending anything on them until we deem them necessary.

8) This whole building has been solely residential since it was built. Not even doctors' offices on the ground floor or commercial storefronts.

I think that addresses the comments & questions posed so far. But both Robert Green and Dave Houston mention stuff that bring me to doubt my filter installation:

Following Leviton's instructions, the filter is installed on two poles of a 15 amp breakers:

---------------------------------------------------- | | | | | | | | L1| L2| |N | | | | | | | ------------- ------------- | | | | | | | | | | | BREAKER A | | BREAKER B | | | | | (1) | | (2) | | | | ------------- ------------- | | | | | | |-----| |----| | | | BREAKER B | | BREAKER A | -------- | | | | (3) | | (4) | | | | | | ------------- ------------- | 6285 | | | | | | | | | | | | | | BREAKER A | | BREAKER B | -------- | | | | (5) | | (6) |-----| |----| | | ------------- ------------- | | | | | | | | | | | BREAKER B | | BREAKER A | | | | | (7) | | (8) | | | | ------------- ------------- | | | | (etc.) | | (etc.) | | | \\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/\\/

This is how mine are installed. At first I couldn't see how this would filter *all* incoming noise, i.e., the branch circuits on breakers 4 and 6 are filtered, but wouldn't the noise bypass the filter on the other branch circuits? (I mentioned earlier I'm an audio visual engineer. If we apply a bandwidth filter or echo canceler to a channel of a mixing board, the other channels remain unfiltered. To filter the whole board we would need to filter its line input or mixed output.)

But I'm assuming the instructions are correct and the 6285 functions as a big "signal sucker" in close proximity to the other branches. In addition, the instructions specify that the filter be wired to a 15 amp double-pole breaker (or two single pole breakers) to meet NEC spec. Doesn't that mean it must be on its own branch circuits?

And wouldn't this mean that if there is noise generated on one of my branches internally (like my old PC monitor), the 6285 would suck it up?

But Robert points out that if I shut off the filter, "all circuits it was filtering should be dead." And Dave points out that "the 6285 only blocks signal or noise from passing in or out of your apartment's wiring."

This suggests that the 6285 should be installed prior to the branch circuits, not in parallel with them. But that would require something far greater than a 15 amp breaker.

Does anyone have experience with this filter and can advise me on its correct installation? Or do I have it installed correctly? If it's installed correctly, why would my "noise level", defined as a Quality Count on a TesterLinc, sometimes double when breakers 4 & 6 (in the above illustration) are switched off, and at all other times be reduced to almost zero when the same breakers are switched off?

Thanks again, and regards to all.

-- Alan T. in NYC

I have no idea what the 6285 actually does and was unable to find any detailed description. SmartHome's and Leviton's descriptions imply that it blocks signals from passing but the connection scheme doesn't appear to support that. If it merely attenuates 120kHz there is no way it can distinguish between your valid signals and external "noise" (i.e. a rose is a rose is a rose).

Insteon only uses RF to couple the two phases. That might cause problems in your environment (especially since they use a fixed frequency) but if it does not, it's other features would likely be highly beneficial in your situation. It will ignore signals from devices which you have not "enrolled" so external Insteon signals would not be a problem. It has good noise immunity. It will not resend forever but only for a fixed number of tries. The signal packet duration is brief. If you have time, read the Insteon whitepaper on the Insteon site.

If you haven't already invested heavily in X-10 it would be an ideal time to investigate Insteon. (more below)

You are misinterpreting the TesterLinc output. It does not measure the amplitude (i.e. level) of a signal but merely counts cycles within an unspecified window just after zero crossing (ZC). X-10 says the receive window extends from ZC+250µS-ZC+900µS and that 48 cycles in that window constitutes a logical Manchester 1. For transmitters they recommend the

120kHz burst begin as soon as possible after ZC but no later than ZC+100µS and continue to ZC+1ms. That means there should be anywhere from 108-120 cycles in the 1ms following ZC with up to 78 cycles within the 650µS receive window. SmartHome does not specify where the TesterLinc window starts/ends. Nor do they specify the sensitivity (i.e. minimum amplitude). I don't think there is anyway to correctly interpret its output without knowing those details.

I would suggest you get a loaner ESM1 from Mart>Thank you all for your guidance. To answer some questions/comments: >

Alan,

You are also misunderstanding some other key things. (You have lots of company.)

Aside from your signal attenuator/blocker the only thing that blocks the passage of 120kHz is the utility company's transformer. This means that using X-10 is a bit like having unprotected sex.

The wiring and breaker panels are bidirectional so any 120kHz that originates within your apartment can reach all other apartments that share the transformer and any 120kHz that originates in the other apartments can reach your apartment. This is true whether the 120kHz is from others using X-10 or is noise from their appliances and devices.

Add to this that should a neighbor be using X-10 RF on a housecode that your CM15A is set to transceive, the CM15A will neither know nor care that the RF is of alien origin and will blithely send the PLC codes. (If you are not using RF, set the CM15A to transceive no housecodes.)

Essentially, you need two whole house blocking couplers (one at each panel). Then you will need a coupler between the two panels. Then you probably will still need to avoid X-10 RF.

How close are the two panels?

It would be interesting to see how ZigBee fares in this near worst-case scenario. I can't see it being any *more* problematic than X-10 will likely be. I can't imagine something as robust as an RF mesh network working worse than primitive and slow X-10 in a dense urban multi-unit dwelling. The repeater function of mesh networks *should* eliminate many of the problems that X-10 faces in problem environments.

How would you rate ZigBee's RF system v. X-10's in terms of robustness? By that I mean reliability of communication and rejection of interference. When you press J5 on, it actually GOES on and never changes state without direct command?

The OP's apartment building more than likely was built many, many years before the average household electrical consumption tripled or even quadrupled. IIRC, household energy use tripled from 1949 to 2000. In old, large buildings, there have probably been numerous upgrades to building wiring. I'll bet that some were done more professionally than others, even with NYC's rigorous code and inspection requirements. As you pointed out, some buildings have gone from low per occupant electrical consumption "office" to high per occupant "upper class residential."

I've found the further you get from "new" the harder X-10 seems to be to implement because of the oddball home-brew fixes we see here where someone pulled a neutral from the wrong circuit to power a switch. Of course, YMMV.

I guess I'd take my chances on a robust, low power RF protocol over an undocumented local power grid that's connected to God knows what. It would, indeed, be interesting to see how both ZigBee AND Insteon do in such a situation. Surely with all your contacts, Dave, you could get someone to treat the OP to a head to head test of protocols using loaner equipment? If ZigBee and mesh networks are all they are touted to be, they should trounce X-10 in the OP's environment. What an ideal "test case."

As for your mystery signal disappearing I am not sure whether that's comforting or alarming. Where did it come from? Where did it go?

-- Bobby G.

Unfortunately, there are no comprehensive ZigBee based systems.

Crestron has some ZigBee based devices but they are primarily a hardwired system and, in the past, have only used RF as an input (i.e. RF gateways). I suspect they intend the ZigBee devices to augment the hardwired system.

Control 4 has some ZigBee switches but they also appear to be limited.

If you haven't done so you should read the RF whitepaper I cited about a month ago from Echelon. While they have a vested interest in making ZigBee and Z-Wave seem questionable, the paper is excellent and the points made have been made elsewhere by academics and others with no apparent vested interest.

Also, while the underlying ZigBee RF protocol is an open standard, it is likely that the higher level communications protocols will be proprietary and xenophobic.

Z-Wave doesn't appear to be making much market penetration.

I d>> Any RF system is likely to be problematic in a densely inhabited urban >> environment.

The mesh network protocol is remarkably advanced and hasn't very much in common with real-time audio transmission protocols. Each device is a repeater and the data rates are high enough so that the time lag for repeated commands isn't really an issue. I asked Dave to comment on the robustness of the current X-10 RF scheme compared to a ZigBee-type mesh network because he's far more competent to explain the difference.

Someone else would have to comment on that. I've not been interested enough in Insteon to look very far into it.

That encompasses several generations of sparkies. You can bet there are some interesting details to the electrical plan.

I believe Dave already pointed out, X-10 is a little like unprotected sex. You *are* linked to every other apartment in the building UNLESS you install a whole house blocker at the service panel that sits between your apt. wiring and the rest of the building's wiring. Gotta be rated at the max rating of your panel and probably installed in its own box. I've never needed one but some people here use them and will hopefully chime in.

They are supposed to insulate you from the rest of the world in both directions. Some vendors call it an X-10 firewall.

Not good. Indicates your lines are noisy enough to randomly trip the modules. Forgive me if I plug RF, but the newer technologies have an incredible amount of redundancy and wouldn't respond to a noise-generated signal. Worst case, a stronger transmitter might block legit transmissions but should rarely, if ever, response to noise as a legit command. That's because they operate so much faster that there is much more room for data checking and security in each command interval.

Dave's covered most of this. Get an ESM-1 meter. It will give you more useful information than quality counts.

X-10 unfriendly devices are insidious. Almost anything from a shaver charger to an aquarium heater can mess up X-10. From what you've been describing, you still have some more signal suckers in your house - you just haven't found them yet. A good meter is essential. Signal suckers act cumulatively. A lot of small ones can really impede the signal but they are hard to find unless you can see their effect on a good meter or a scope.

I thought you didn't have subpanels but two equivalent panels feeding one combined apartment. Dave will correct me if I am wrong but I think it's possible that twin panels will have phase issues where subpanels won't. I disconnected my HCA02-10E shortly after installing it. Too many "broadcast storms" of unknown origin.

I would start with a good meter (I use the Monterey because it's got a digital readout but it's incredibly pricey). Then I would set up a standard reference - hopefully with a maxicontroller and a lamp module. I would start at the ends of two branch circuits and read the signal strength. Then, turn off all other breakers and read the signal again. If it's about a volt higher, you then turn on the other breakers one by one until you find the one that's sucking the signal.

But it sounds like it's nearly 70 years old. Think of how few electrical appliances there were back then.

Yes. It would filter only what on that branch circuit. It's not what you want.

Ubetcha. Smarthome says:

"Designed for installations where the Whole-House Blocking Coupler or X10 Pro Whole-House Blocking Coupler can't be used, the Signal Attenuator reduces the signal strength of external X10 signals. Other outside noise sources, such as baby monitors, that are on a similar frequency to X10 will also be reduced."

Why aren't you using:

# Blocks X10 signals from entering the home # Couples X10 signals across 2 and 3 phase systems (Image says good for 225A)

-- Bobby G.

Alan,

What has happened with your problem? Did we confuse you too much?

Alan, I too am interested in your two panel setup as I have a similar discussion going on in another post. Did you give up or did you try the 2 HCA02-10E's ??? Good luck Carl Ford

No, I'm not confused, but I just got very busy with my day job and came down with a minor illness, so I couldn't follow up for a while.

After considering everything, and after both my electrician and I tried to discuss this with Leviton on the phone (their expert was a bit rude), I think the next step is to write to Leviton (I have a friendlier tech's e-mail address) including some of the detail I wrote to this group and ask for a better explanation or description of their product.

Our lights are no longer going "crazy." They do occasionally shut down, about once an evening, not three times an hour, and they no longer spontaneously switch on. But they are not yet steadily controlled by the CM15A, probably because we do have the attenuators installed (improperly, I fear) and don't yet have the HCA02-10E's installed. Much of the time, the controller works fine, but when I'm metering sustained, stray 120kHz activity it doesn't work.

Considering everything so far...

1) Yes, I do want/need a "firewall" so to speak, although I understand such a device would not digitally block all unwanted stuff (as a computer network firewall would) but attenuate it by absorbing it (as does the 6825) or phase-cancel it (as does the 6824 or PZZ01) down to tolerable levels.

2) Acknowledging that "X-10 is decades old. The designers just couldn't foretell how much things would change in 20+ years...," then unless the incoming noise levels are EXTREMELY high (greater than the

30:1 attenuation provided by the Leviton filters), wouldn't the proper application of hard-wired filters on my panels combined with plug-in filters on my own noisy appliances protect the network against this, without a need to "generate your own power and disconnect from the grid"?

3) I'm just too wary of RF solutions in the Big City. And what is likely to happen to any RF network's integrity in a few years? Didn't we all love our 2.4GHz cordless phones until wireless home network routers came out? I don't use the RF function in the CM15A; I just use it as a whole house Sabbath timer (well, technically, half a house, since I'm isolating my two service panels and will ultimately use two controllers). I have the RF function on my CM15A shut off except during testing.

Or should I trash my PLC system, go with RF and plan on trashing *any* home control network every 10 years or so because we "just can't foretell how much things will change"?

I propose to this group that "new" isn't necessarily better, "old" isn't necessarily archaic or obsolete so long as we have the network integrity protected. That could mean building an effective PLC firewall, or it could mean encasing my home in concrete and lead to shield it against anything stray flying through the air. I prefer to filter just the wires.

4) I just don't "get" how the 6285 attenuator is supposed to work. If it is supposed to knock down everything flowing through my house at around 120kHz, then why does my unamplified controller work during non-noisy times? And if it installs on two 15 Amp branch breakers (as per the written instructions), then how does it block my neighbor's noise from flowing from the main feeds onto the other branches in my panel? (Please see my earlier illustration.) Is it an effective "signal sucker," sucking everything at the panel? If not, what protects my WS12A dimmers on the other branches the 6285 isn't wired to? If it is an effective signal sucker, why wouldn't it take care of my noisy PC monitor or other devices (every "laptop, UPS, shaver, battery charger, CFL, dimmer, etc.") as well?

But I'm speaking hypothetically now. I'm not getting the 6285 to perform consistently, so I think it's not properly -- or effectively -- installed.

When speaking with Leviton last week, the first tech said we should connect the 6285 "as close to the incoming feed as possible." That meant connecting it to two separate 15 amp breakers, each breaker the first in line on its phase, and suggesting that this could block incoming noise from trickling to other branch circuits. But then the "specialist" who took over the call practically barked, "No, I don't want this on two separate breakers. I want this on a single, double-pole breaker!" So much for placing the filter as close to the incoming feed as possible... Time to write to Leviton.

5) Before I sink in an additional $85 for each of two HCA02-10Es (and possibly knock holes in my plaster & lath walls for the boxes to house them), I want to know that they will be effective. Does it boost all 120kHz activity? Won't that put me back where I started? Does it "recognize" clean X10 code separate from noise? How? What happens when a clean X10 packet collides with noise? We already know that X10 won't work when two good packets collide. While I can get around some packet collisions by programming the CM15A to repeat commands, what do I do to get around 3 - 4 hours of sustained noise?

Can't one just amplify the output of a controller before it plugs into the powerline? That would introduce X10 signal at several volts onto a powerline network where all 120kHz activity is then attenuated by a whole house filter. Does anyone make such a feed-thru amplifier?

That's where things stand. Given my workload and the upcoming holidays, I don't think I'll be getting to this until 2006.

Merry/Happy whatever-you-celebrate, everybody!

-- Alan

I still think you need one PZZ01 _assuming_ that you can put that one upstream of the 2B-2C split. Are there separate feeds from the basement to the 2B & 2C panels?

I'm also a bit puzzled by how the 6825 works. It would really help to see a schematic. The effects of a signal sink are somewhat localized because of the impedance of the wiring itself but I don't quite understand how a 6825 can attenuate alien signals without also attenuating legitimate signals trying to go from 2B to 2C.

My earlier recommendation of two HCA02-10Es was based on...

Two ACT CR234s are probably a better choice because of the SCC feature.

With X-10, one other thing might help. The LM14A lamp modules and (I suspect) the Leviton switches that respond to extended codes do a better job in the presence of low level 120kHz noise than do LM465 lamp modules and X-10 made switches. However, we still don't know the amplitude of the 120kHz noise you are seeing.

The repeating couplers do not repeat all 120kHz and they don't really amplify (at least those made by ACT don't) but merely repeat the X-10 signal during the time frame for the second copy of the X-10 command.

I still th>No, I'm not confused, but I just got very busy with my day job and came

| I'm also a bit puzzled by how the 6825 works. It would really help to see a | schematic.

I don't believe there is a 6825, but the 6285 (which I think is the one being discussed) is very simple. It has two 1uF capacitors (each with a small protective(?) series resistor), one from each line to neutral.

|The effects of a signal sink are somewhat localized because of |the impedance of the wiring itself but I don't quite understand how a 6825 |can attenuate alien signals without also attenuating legitimate signals |trying to go from 2B to 2C.

It can't.

Something I always thought would be neat (and I proposed this to ACT) is a repeater that bridges a low-impedance onto the line during the transmission of a "0" (rather than doing nothing). This would provide an active solution to noise problems. When my last CR230 failed with the dead high-voltage power supply it managed to block transmissions rather than repeat them, so it might not even require significant changes to the design. (I.e., a good coupling network for 120kHz probably also makes a good sink if shorted rather than driven.)

Dan Lanciani ddl@danlan.*com

I realized I had transposed the 2 & 8 about a µS after clicking the send button.

Then if the 6285 really will cause as much trouble for interpanel signals as it will for alien signals, I don't see any advantage to using them here.

An ACT 230 is "sensitive to 80 millivolts peak to peak minimum" and outputs "6V peak to peak @ 5 ohms minimum".

So if it receives a signal at 80 millivolts and retransmits it at 6v it does in fact amplify by 6000/80 = 75X = 37.5 db gain.

And an ACT CR234 which is "sensitive to 25 millivolts peak to peak" and outputs "5V peak to peak @ 5 ohms" can amplify up to 5000/25 = 200X =

46db gain. Same principle applies to Leviton's current and past units. For example, the HCA02-10E is specifically identified as a "System Amplifier". ...Marc Marc_F_Hult