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[hollisav]

I finally got the electrician over to hook my XTB-IIR up to 220v and it seems to be working as it should.  However I am having a problem with line noise on one phase.  I have tracked it down to my florescent lights in my shop which is where I have my AHP and computer running from.  The XTB-IIR is also hooked up to this panel.  The panel is a sub panel with the wire running underground from the house.  If my light switch is on the noise level on my XTBM is up to .19.  if I shut the switch off the noise level drops to .00.  The electrician installed a XPF on the light circuit at the panel and it had no affect on the noise level.  Could it be because the sub panel has a isolated neutral?  I checked the voltage level over at the house circuits off from the main panel and I am getting over a 5 volt signal over there so I should have no problem expanding my X-10 over there.  I found one 3 way CFL over there that dropped the signal down to less than a volt and I used a XPPF and that took care of that problem.  However I don't understand why the XPF is not doing its job on the florescent lights.  The lights have 2 4 foot tubes in each fixture and the electrician installed the new low power rapid ballasts in each one.

Thanks for any and all info
hollisav       

[dave w]

Interesting. I guess one question I have is why install the XTBIIR on the sub panel? When you say "isolated neutral" you mean the neutral on the sub panel? Isn't the sub panel fed from the same line coming in from the meter? Also if on separate meter, are both meters fed from one pole transformer? Also, aren't the neutrals bonded to the ground line in the panels, or are they floating? In my panel, the neutral buss and the ground buss are essentially the same circuit. If there is true isolation I would move the XTBIIR to which ever panel has the most X10 modules on it. Same goes for the "electrical" location of the CM15A.
Just curious questions.

The XPF could be defective, but it would be a lot better to have the XPF located in the shop at the noise source.
$0.02

[hollisav]

The XTB-IIR is on the sub panel because that is where i have the computer with the AHP controlling it from.  It has the CM16A plugged into it.

Yes I mean the sub panel has the isolated neutral.

Yes the both come off from the same meter and the neutral and the ground are tied together in the main panel off from the meter.  According to the elect. a sub panel must have a isolated neutral.  Makes no sense to me.

XPF is brand new.

Thanks

hollisav

[JeffVolp]

The new electronic ballasts can be serious noise generators.  The XPF is a notch filter, which just blocks noise right at the X10 bandpass frequency.  It is likely that your shop fluorescent lights are generating noise outside the X10 bandpass, which is being picked up by the XTBM.  Whether that will bother X10 modules depends on the selectivity of their input stages.

I would expect to see some reduction in the noise reading after the XPF was installed, even if the noise is outside the X10 bandpass.  So, I wonder if the XPF was installed correctly.

To be conservative, the XTBM input bandpass is wider than the X10 modules themselves, and it will pick up noise that has the potential to cause a problem if the frequency shifts into the X10 bandpass.

The XPPF is a low-pass filter, and will block noise over a wide range of frequencies, beginning well below the X10 bandpass frequency.

Jeff

[hollisav]

The XPF was installed correctly, black to breaker, red to load and neutral to neutral buss.  should I use a amp probe on the light circuit and if it is under 5 amps I could modify the circuit before the panel and install a XPPF.  Just an idea.

Thanks

hollisav

[Brian H]

Be very careful with an XPPF. It gets warm and smells if pushed too close to five amps.

Also we had a user burn some up with fluorescent lights. As they drew current out of phase and though an ampmeter said OK. The current was too high.