online ups vs x10

[Brian H]

Have you used a Scope to look at the output?
It may not be harmonics. It could be the UPS has a filter on it that reduces any noise and harmonics to the low level you are seeing.
In that case. It could be the filter in the UPS absorbing the X10 signals as noise.
I don't have any information on who may make a heavy duty filter designed for X10 use for 240 volts 50 cycles.
X10Pro made a XPF 20 Amp wired in filter for use on 120 volts 60 cycles. Though with X10 closing their factory and having a few select modules made. I believe the XPF was one of the now gone devices.
I believe the 240 volt European Modules, like from Marmitek, may not be effected as they have their own manufacturers.

[Noam]

What else do you have on the UPS? If you have a computer (or computers) on the UPS, those power supplies might be creating noise which, added to noise created by the UPS, are interfering with the signals.
If you can, you might try plugging both the CM15A and the module you are trying to control, into the same power strip, plugging that into a filter, and THEN plugging that into the UPS. The filter might be able to block the other noise that is interfering with the X10 signals.

Can I ask why you need the CM15 and the X10 module to be on the UPS?

[Dan Lawrence]

I looked up "online ups" and the first thing pops up is United Parcel Service.  Can you provide what you mean by "online ups"?  Thanks

[Brian H]

Dan;
Basically the UPS is always running to provide the AC power to the load.
When the AC power from the power lines is there. The Charging circuit charges the batteries and runs the inverter making the AC output.
When the AC power from the power lines is lost. The inverter runs from the batteries.
With an online UPS there is no short loss of power to the load. It never even glitches for a brief time.

[Knightrider]

Try "Uninterrupted Power Supply".  Some switch loads very fast, some are true floating power supplies.

[Dan Lawrence]

Thanks.  Now I understand.  An Uninterrupted Power Supply is good where your local power company is always going off and you need power that always works.

[bkenobi]

I run a UPS my computers and on my AV equipment.  I don't necessarily need to use the equipment when the power is out, but I was concerned about power flickering.  When trees touch the lines (happens a lot in the Pacific NW with all the wet fir trees) the power doesn't go out, but it flickers the lights and can freak out a PC power supply.  Since most events only last a second or so and they happen in clusters, I didn't want to have the computer or DVR get scrambled from consecutive reboots.

I found that all of my UPS units are signal suckers regardless of brand and ended up filtering all of them.  I've never tried running X10 behind the UPS, but in my case it obviously wouldn't work since I'm filtering.