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

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"AlanTinNYC" <AlanTinNYC@xxxxxxx> wrote in message

<stuff snipped>

> 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.

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.

> (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.)

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.

> 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.

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

> There seems to be good isolation between
> the two service panels.

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 have not yet installed Leviton
> HCA02-10E signal amplifiers,

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

> 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).

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.

> 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.

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.

> 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.

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?


> 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.

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.


> 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?

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.


> 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?

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


> 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?

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.

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

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.