Troubleshooting X10 Home Automation
You just installed a new module and you go to try it and it doesn't work. Maybe it only works partially (will turn on but not off, or vice versa). What ever the case, it isn't doing what you want it to do. There are only five fundamental reasons why it doesn't work. In order of importance these are:
- User Error,
- Faulty Equipment,
- Too Weak a Signal,
- Too Much Powerline Noise, and
- Phase Distortion.
I will describe each of these reasons in detail below:
Double check to make sure that the unit and house code are set properly. If you are using an RF remote, make sure you are transceiving that house code and that you are within range of the transceiver (you can verfiy this by turning a different module on or off with that remote). Make sure that the module has power to it and that in the case of wall switches that the output isn't disabled. If you are using a lamp module or dimmer switch, make sure that you are using an incandescent light bulb and that there aren't any other electronics being switched (ex. touch lamp, motion sensor, light sensor, etc).
Try using a different module at the same location using the same house and unit code. If it works then the other unit might be faulty.
Too Weak a Signal
Household wiring wasn't designed with home automation in mind. As the X10 signal travels through the house it gets weaker and weaker. Professional installers will have an instrument to measure the signal strength to help them debug this problem. Since most home owners don't have such a tool, we have to rely on other techniques.
Poor Phase Coupling is by far the most common problem. If you want to use more than a few modules, you should seriously consider having some type of phase coupler.
If you have a phase coupler, another potential cause of a weak signal is Signal Absorption. Power bars and UPSes which Filter EMI/RFI noise will absorb X10 signals. Other electronic equipment can also absorb X10 signals, but without test equipment it is difficult to tell the if it is absorbing signal or generating noise. Fortunately using an X10 Noise Filter will solve either problem.
If all else fails you can fix a problem of too weak a signal with a signal amplifier (not to be confused with a signal repeater). Since they will also amplify powerline noise and can weaken strong signals, you need to choose carefully where to put them and they should only be used as a last resort.
Too Much Powerline Noise
You can't hear powerline noise, but if you have too much of it, your modules won't be able to "hear" the X10 signals. Powerline noise can be created by fluorescent lights, electronic equipment and appliances. If you figure out what equipment is generating the powerline noise, an X10 Noise Filter can be used to fix the problem.
This is extremely rare and is typically only seen in certain industrial buildings. You will almost never see it in residential buildings.
If you have ruled out user error and you have a phase coupler (or coupler/repeater) your problem could be one of three things:
- There is something on the powerline that is generating noise,
- There is something on the powerline that is sucking up signal,
- Noise is coming in from the outside of your house.
Without a signal strength meter it is challenging to find the source of the problem, but it can be done.
First of all, make sure the signal amplifiers are located somewhere where the signal is weak. If the signal is strong, the amplifier can actually make the signal weaker. You also have to be careful that they aren't close to a noise source, as they will also amplify the noise. For most people, signal amplifiers are not necessary. I would unplug the amplifiers when doing your tests.
If that isn't your problem, turn off all the circuit breakers in your house except for the one your transceiver is on and one of your wall switches is on. Hopefully the switch will now work properly. If not, unplug everything on those two circuits and see if that helps. If it still doesn't work, you have a major problem.
Assuming that you get the switch working, start turning circuit breakers on one at a time, checking with each one that the switch still works. If it stops working, turn that breaker off again and continue with the next breaker.
Once you have tried every breaker, you know that one or more things on each of the circuits that are off are causing you problems. For each of these breakers you can narrow down what is causing your problems by unplugging everything on those circuits and plugging them back in one at a time similar to the way you did things with the breakers.
One other note, don't assume that just because something is plugged into a noise filter that it won't cause you problems. Some things will generate more noise than a single noise filter will remove. It is possible that something needs two noise filters.
Key Topics: on, off, noise, circuit, phase, coupler
Written by Roger H. 08:58, 10 May 2006 (PDT)