Hello all,

I am hoping for some help with a recent problem. I am new to x-10, having added a PCS switch to my old home and controlling it through my mx-500 remote, about a year ago. Then I recently installed 3 single pole x-10 decorator switches, model ws12a. The 3 are installed in a bank of light switches, and on a different circuit, but the same room as my TV. They are all able to be controlled via the mini-controller, and work fine as switches by pressing them.

My problem is that for some reason, on one of the switches, when the slider underneath the switch is turned to the "on" position, causes mild interference patterns on the TV. It does this whether the switch itself is turned on or off, but simply when the power to the switch, via the slider, is turned on.

I don't really understand (but am trying to learn) about interference, signal strength, etc. I don't know where to start with trying to figure out the problem. Might this be a wiring problem, or interference, weak signal, etc.

Thanks in advance for any help or direction.

Noah

Noah, most people don't mess with the slide switch; it's there for UL approval, for a positive-off when bulb-changing. In normal use, you don't need to use it.

Your description leads me to believe you're getting simple arcing, which indicates a less-than-perfect electrical contact. It's a somewhat common malady with some X-10 switches.

The TV interference is typical RF noise generated by the arcing and is being picked up by the TV. I'd bet you could hear crackling at the same time on an AM radio tuned between stations.

My opinion is that no damage is being done, but you should exchange the switch, if it's new enough to be warrantied; the arcing is a sign that the contacts may soon fail completely.

Larry
www.fineelectricco.com

Thanks for your help in answering my question Larry, and I am sure everyone else appreciates all the time you put in to help here.

Unfortunately, I have been unable to replicate this problem now with any consistancy, although I probably should replace that switch, now the problem occurs even without power to the CIRCUIT controlling the switches, so it looks like that is not the problem, must be with the satellite box (I assume).

But my follow up problem is that I have these 3 switches, that are on the same circuit, same wallplate, and all 3 are controlling separate outdoor lights in front of the house. 2 are controlling incandescent lights, 1 (that I am having trouble with) is controlling low voltage landscape lighting (is this still considered incandescent?). I have all 3 set to the same house code and address, and are controller with a mini-timer unit. The switches are all WS12A 's (which seem like cheap pieces of #*(+@ in my opinion). My problem is that the one controlling the low voltage lights will turn on with no problem, but will only turn off occasionally via the timer. The switch works fine with direct control.

Any ideas? I would assume replace the switch as a starting point?

Thanks in advance for any help you might have.

Noah

Never mind, it appears I solved my own problem. Looks like a phase issue, when I moved the location of the controller to the same circuit that the lights were on, the problem went away.

Noah

Noah, glad you experimented. That's the best way to learn.

To answer your question, low-voltage landscape lighting is transformer-powered, which makes it an inductive load. They should be controlled with a transformer-compatible X-10 dimmer or a fluorescent-compatible X-10 switch (no dimming).

Check with Bill @ Home Automation Net.

Larry
www.fineelectricco.com

"low-voltage landscape lighting is transformer-powered, which makes it an inductive load. "

But the secondary is connected to a resistive load, which reflects back to the primary.

Hmmm I didn't understand the last post with the primary and secondary, but what is interesting is that after moving the timer/controller and having the problem solved, after about 3 weeks, the problem has now re-appered. Should the next step be to get the device you mentioned Larry? Just so I know for the future, is that device usually always necessary with flourescent or transformer altered situations? Thanks again.

Noah

Noah,
re your last post, yes.



And if this were the perfect world that physics teachers teach about, you would be completely correct. There are inductive losses in the transformer that still come out looking like an inductive load to the 120 volt side. The problem, then, is that this inductive portion of the load causes there to be current flowing when the 120VAC voltage has fallen to zero...this freaks an X-10 switch because it is designed to switch when the voltage and current reach zero. Can't happen with an inductive (or capacitive) load.

The less current that is drawn by the secondary, the larger a percentage of overall current draw is this inductive part. Theoretically, again, you could minimize the inductive component not by changing the inductive component, because you can't, but by increasing the current drawn by the secondary into resistive loads. This will minimize the percentage of primary current that is inductive in nature. That, in turn, will minimize the (percentage of full) current flowing, as a result of the inductive part of the load, at zero voltage crossing when the X-10 switches.

First, an X-10 switch still might blow with that amount of inductive load, and second, you might have to run the transformer HOT HOT HOT to get to this place!

You could go out and get motor capacitors, and place them in parallel with the primary of the transformers, and look at voltage and current on a dual trace scope, adjusting the amount of capacitance until the load is truly resistive. (Be sure to connect through conduit or in a code-appropriate electrical box.) Then when one bulb blows, your load might not be resistive and the X-10 might blow anyway.