Nuts and Volts - June 2017

64 June 2017

This sounds like interference that is coming from some other device that you probably placed nearby the radio, like a cell phone charger or dock. Sometimes, LED lamps can create nasty interference. So can flat screen TV sets and computer monitors. (Even when they are OFF!)

Try unplugging various devices and eventually you should be able to find the culprit. The other option is to use a transistor radio and walk around to see where the noise gets worse. This is how I found interference in the past.

William Barnett West Haven, CT

[#2174 - February 2017]

LED Compatibility?

I replaced some outside

60W bulbs with CREE dimmable LED replacements. The lamps are controlled and dimmed using X10 switches. When switched off, the lamps still glow at about 20% and will not shut off completely unless I use the disable feature of the switch. However, this prevents the timer from automatically controlling the lights. What causes this and is there a fix, or are LED replacements not compatible with X10?

#1 Conventional X10 switches require a small current to run through the load (i.e., an incandescent light) in order to work correctly. For nonincandescent loads such as CFL or LED lights, you need an X10 switch specifically made for them. I currently use a WS13A X10 wall switch and also an XPFM X10 fixture module to X10 switches are not dimmable though. In general, LED lights need a dimmer specifically made for LED lights. I have had good success with the Lutron CL digital dimmer (e.g., MACL-153MH) as a manual dimmer, but I do not know of an X10 compatible dimmer designed for LED lights. Perhaps someone else knows of one that will work.

Dan Koellen Roseville, CA

#2 They’re compatible; what you’re seeing is the leakage current on the output of the X10, which is still enough to cause the LEDs to light up barely (and which isn’t visible on incandescents.) If you truly want the LEDs to go out, though, you’ll have to look for something better than the old X10 designs.