Now the Bad and the Ugly

Posted by Steve on Thu, 08/24/2006 - 3:46pm


So if X10 is the coolest thing since the pop top beercan, why isn't it more popular? If X10 devices have been on retail shelves since 1978, why doesn't your house have them?

For one thing, X10 has always lived in the hobbyist's domain. The devices were first marketed through Radio Shack stores and are pretty much only available through mail order. Even today I talk to professional electricians who've never heard of X10.

Secondly, when a client asks an architect for a home automation system for his new seven-figure McMansion, he's going to get a five-figure home automation system, complete with dedicated control lines, a basement master panel/punchboard and probably lots of disappointment when he needs to replace a proprietary switch twenty years from now.

Third... well... I admit it, X10 can be problematic. If you've cruised those Smarthome pages you might have noticed among all the useful devices a lot of diagostic equipment, repeaters, line bridges, noise filters and so forth. That's because X10, as nice as it is, is dependent on an imperfect vehicle: the "dirty" household electrical backbone with lots of noisy household appliances sharing the road. It's not a matter of if you'll run into problems with your X10 installation but which ones.

You can't cross the river without a bridge

The first problem you'll almost certainly encounter are devices which respond to X10 commands on one circuit but not on another. There can be a few reasons for that but the number one cause is that the X10 transmitter is sitting on one power leg in your breaker box and the X10 receiver is sitting on the other, out of phase with each other. If your household power arrives on two legs, as most do, you'll need to invest in a coupler. This bridges the two legs in your breaker panel so that the X10 signal can pass unmolested. Mount it in an electrical box in or on the breaker panel and install its two wires on breakers on opposite legs. In most localities, it can share two existing 15a breakers.

That's work which really should be done by a licensed electrician. However if you have any 220-240v appliances there's a much easier solution.

Avoid couplers which are also repeaters. My experience has been that repeaters need to be carefully located in your installation (if you need them). They can actually create more problems than they solve but a coupler is almost mandatory.

Say again?

Another problem is long circuit runs or runs which also have noisy appliances like TVs and satellite receivers on them. If you run into problems here, invest in noise filters first. Install these on likely culprits (which are generally cheaply made computers, TVs, battery rechargers and so forth). The rule of thumb is that every house has at least three appliances which generate noise potentially severe enough to affect X10 operation, if only intermittently.

There's not much you can do to make a long circuit run shorter. I have a couple of them in my house. In this case, a repeater may help, but I've still got a transmitter switch that can't talk to a desk lamp eight feet away because there's probably 200 feet of power line between them.

Install a repeater on the same circuit as the deaf device, as close to the breaker panel as you can get. But, beware: repeaters can also repeat noise. A moderate amount of noise in a line, such as from fluorescent lights, can be amplifed in the system and cause other X10 devices to go deaf.

"Hobby quality"

That's how one home automation professional I spoke with described the quality and dependability of X10 products in general. Indeed, I've got some personal experience with that. I had a pull chain entryway light in my old house which used candelabra bulbs. When the cheap, box store-quality bulbs burned out they would occasionally fry my $40 in-ceiling receiver module too, until I got rid of that fixture.

X10 switches are also vulnerable to high humidity. The X10 three-way switch in my garage never works on hot, rainy nights and my basement relay switch sometimes takes three or four hits to work during the warm months. Part of the problem is inherent to X10's open loop protocol where a receiver doesn't acknowledge to the transmitter that it got the command.

Earlier this summer, during a week of incredibly warm and humid NYC weather, I came home to find my outside lights flickering like a haunted house. I thought it was the breaker and changed it. Then I thought it was a bad neutral in the circuit. I checked that. Then I changed the X10 switch. That worked for about two days. Finally I installed a higher-quality Insteon X10 switch and the problem disappeared.

It's a shame that big name companies like Leviton can't do a better job of hardening their X10 products for the real world. The overall quality of X10 devices has improved even in the few short years I've worked with them. Nevertheless, it's pretty annoying when I have to explain to my Polish-speaking house cleaner how she has to hit the basement switch four times in the lower left corner to get it to work on warm days and to only tap the kitchen light switch once or it will go into "dim" mode.

SmartLabs' Insteon devices seem to be more durable and better designed overall so that's what I'm upgrading the house to now.

The X10 Delay

This probably bothers most people initially. Because of the nature of the X10 protocol there's a short delay between the time you hit a transmitter switch and the receiver responds to it -- generally about one second. Unless you've programmed a macro on a third X10 device, in which case it's more like two seconds.

All I can say is that you get used to it. However, Insteon devices fix a lot of these problems. And that's where we'll go next.