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

["AlanTinNYC" <AlanTinNYC@xxxxxxx>]

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