Home Automation Topic...

[arjo_reich]

Originally posted by physis:

Actually, the "perfect world" for most automation systems is to have all controlled devices not on the same circuits as anything that could produce RF interference...and because the most commonly controlled devices are luminaries, this is where it most often applies.

There has to be a mistake in your interpretation of the manufacturers literature.

These systems will simply have to work in a real environment that actually exists. Anything so delicate as to require it's own circuit for each load has two problems.

1] Dedicated circuits do not "cleans" noise from the system. They reduce it "somewhat", at best, whatever amount that might be.

2] Something that does have that kind of requirement might well be so sensitive as to be unable to operate correctly in way too many environments. The walls will be more or less permanent.

I don't have a lot of experience with these systems but I think I would stay away from any thing that either uses RF or can't tolerate it.

You should definitely look for recommendations from sources that are not salesmen.

Let me try to elaborate, although it sometimes it can get thick for me and go over my head as well.

Inline devices have three major issues:

Phase Leg Issues:
In this scenario the transmitter is on one phase and the receiver is on another phase. The only way they can communicate at this point is either through the local POCO's transformer - assuming the signal still has enough strength to return to the receiver after that journey...or through some type of passive bridge. Usually this is a 240v device somewhere in the home that is bridging the phases for you (not always effective) or you can purchase device designed specifically for this purpose.

Signal Interference:
Pretty much all devices with electrical motors bleed interference into line introducing noise that the transmitter's signal has to compete with. Isolating the large offenders; disposals, dishwashers, refrigerators, washers and dryers, etc. to the phase NOT being used by the controlled devices will help immensely but you are right, it does not completely eliminate the problem.

Signal Suckers:
This one is the most interesting - to me, anyways - because some devices in a home simple love to eat the signal. Basically some devices in your home, typically those with a converters or transformers are suspects because they will often provide a lower resistance to ground for the signal. The worst seems to be UPS devices for computers which are, by design, supposed to "clean" the power before passing it on to the computer.

Obviously you cannot create a perfectly clean environment for inline systems like these, however when you have the opportunity to take little steps like this in advance you help avoid the cost of the various manufacturers expensive bridges, filters and amplifiers.

 

[jwelectric]

Re: Home Automation Topic...

What in this world are we talking about here? When my TV gets fuzzy I just reach out the window and turn the antenna a little. Of course this don?t help much if it is raining.

The only thing in my house that would bridge 240 is the water heater cause we traded the cook stove fer a good wood stove last week. Sucks I told the wife we could fill a tub with water and let the sun heat it till winter came.

 

[suemarkp]

Re: Home Automation Topic...

I have all of these issues in my house which utilizes the X-10 automation protocol. I built my own phase coupler (a capacitor and a coil) which extened the range of controllers.

My computers (or perhaps their power strips) suck the signal where the plug in on a branch circuit. Things upstream can be controlled, things downstream cannot. You can buy isolation filters to keep the sucker from sucking, but many of these are limited to about 5 amps. If the device you want to control is also a signal sucker, then you're toast.

I also have some interference problems, but this isn't from X-10. I have some leviton electronic timer switches that I use on bathroom fans. About half of the time, turning off a fluorescent light will turn a fan on. Sometimes, these same lights will trigger my motion activated floodlights too. I'd be interested in any solutions people have for this problem. I've considered ferrite beads, but don't know if that will help or even what frequency range my spikes are in.