My (Troublesome) Experience with Installing my own Smart Devices

Jim Baldwin
Dec 10, 2018 · 10 min read

My house was built in 1901, well over 100 years ago. The lighting in my kitchen is a bit of a mess; the various lights have wall switches in different, seemingly random, places. At night, it’s a lap around the room to turn the lights off. Some of the light switches are on surface boxes with surface conduit carrying the wire to the lights. I suspect the original lights had pull-chains and the switches were added later by someone unwilling to open up the wall. Pretty ugly.

Ugly

While considering hiring a painter for the kitchen, I decided this is an opportunity to fix some of these issues first: Move the switches to where they belong, hide the wires behind the walls, and add “3-way” remote switches to the lights so they can be controlled from either side of the room.

Wiring 3-way switches can be a pain (see “On 3-Way Switches” below). While I am committed to moving a few wires to get the switches closer to where I want them, the idea of running a whole bunch of 3-conductor cable around the kitchen would have bumped the project over the cliff into a full-on, wall-gutting remodel job.

I’ve been playing around with some smart home components lately — controllable switches, a door sensor, and a motion sensor — compatible with the SmartThings system. It appeared that I could implement the remote 3-way controls virtually instead of having dedicated wires, which would keep this project under control. As a side benefit, I could get a few nice extras like being able to turn everything off with an Alexa command, noticing no motion activity, or a single button press.

So I decided to make this project an official toe-dip into the current state of the smart home world. This isn’t my first time here. At my last house I used Universal Powerline Bus (UPB) devices to add some controls where I wanted them. Enough time has passed that I have forgotten the pain, and state-of-the-art has moved on, so this was a chance to catch up.

This article is about my particular journey, hopefully to benefit anyone thinking of diving in on a project like this themselves. Note that this is, in particular, a project aimed at a permanent installation, which is an important distinction. While I can achieve some of the goals with plug-in components, the polished effect I’m looking for requires components be installed in the walls with a clean look.

I’m trying to be as thorough and accurate as I can be, but do know that the ecosystem is complicated and its not always easy to know what’s possible. If you read this and see something I missed, please drop me a note.

The Project

Some goals for the project:

  • There are 4 controllable lights in the room. I want to have a bank of 4 switches at each entrance to the kitchen, so I can turn lights on/off no matter which door I enter or exit through.
  • I don’t want to run any more new wires than I absolutely must.
  • I don’t want to depend on batteries.

Demolition

I started by pulling the face plates off of my wall switches, to see where I was going to install new smart control devices, and I encountered the first major issue: The existing electrical boxes are too small for the modern smart dimmer switches. Ouch! But, this is a solvable problem. Home Depot sells a variety of “old work” boxes that are designed to be installed in a wall without being attached to a stud. They come with little ears that grab onto the back of the drywall (or in my case, plaster/lath) to hold the box securely in place. So after trip #1 to Home Depot I started installing new boxes.

Old boxes can be pretty small

This goes pretty well, though I have to say, connecting 12-gauge Romex wires to switches even in modern large wall boxes involved a good amount of cramming as the wire is really hard to wrangle inside the box. With the large dimmer going in, even less room is available. I know it’s a bad idea to cram, so I try very hard to get the wires to just the right length and bent around in just the right way, but in the end, I do a little cramming to get everything to fit. Don’t tell anyone.

Certainly, retrofitting a house for smart controls is noticeably tougher than for new construction.

Neutral Deficiency

With the new boxes in place I took a look at the wiring. Some of my switches are “loop-wired”, meaning the power goes to the light first, then loops through the switch to make or break the hot connection, so there is no neutral wire going to the switch.

Loop-wiring vs. modern wiring

This approach was common in older houses, but building codes (thankfully) no longer allow this. The correct approach is to run the power (with neutral) to the light switch first, then pass both neutral and switched line voltage to the light. The reason for this is fire safety, but it solves a problem for smart switches, too.

How current flows in the two types of wiring

Loop-wiring is a problem because most smart components need power to operate even if the light is off. The reason is a bit complicated, but basically, if the light switch itself needs power, it will need to conduct current. The same current that is pulled through the switch is pulled through the light. This means the light will always be a little bit on, even if the switch is off. To complicate this, you could get away with this in the days of incandescent bulbs, which are resistive loads, because the bulb would conduct the current but it just wouldn’t be bright enough to notice. For modern LED bulbs, this will only work if you have “dimmable” bulbs. Non-dimmable bulbs won’t pass any current until the voltage is high enough to turn on the LEDs.

There are some approaches to solving this, such as adding a bypass load across the light at the fixture that will conduct something when the light is off.

Either way, the amount of power a smart switch/dimmer can use in a non-neutral solution is very limited, so you’ll find that devices that work this way don’t do a lot.

On 3-Way Switches

Traditional 3-way switches run a 3-conductor Romex cable (a “runner”) from the master switch to the remote switch (daisy-chained to additional switches if more than 3-way). Basically, the light is on if an odd number of switches are in the ‘on’ position. This works for on/off 3-way configurations, but not for dimming. If you’re dimming the lights, this needs to work a little differently. Some companies make dimmers with remotes that communicate by using the runner wire to carry a digital signal, so the remote switch, when adjusting dim level, sends the desired level to the master switch and it does the actual dimming.

Typical 3-way switch wiring

The problem here is, while I was able to pull neutral wires to my switches, pulling 12/3 Romex across the room to enable 3-way switches is not an option for me.

But we have smart components, right? Could a remote dimmer not just send the desired dim level over the smart network? Surprisingly, this isn’t common. The Z-wave dimmers I have tried don’t support sending a dimming level to a dimmer from another dimmer or remote. The only thing a remote switch can do is ask the master to turn on or off. This leaves me a bit unsettled as it doesn’t feel consistent to me.

I only found one solution that lets a remote control dim level, Lutron’s “Caseta” dimmers. But, batteries in the remote? Really?

OK, Fine. Batteries.

Here’s where I had to give up on my desire to not have batteries in my installation. While I don’t like relying on batteries in infrastructure, the only solution I found for smart dimmers with 3-way capability, not requiring a runner, allowing to set brightness from the remote, comes from Lutron. Their “Caseta” line offers what they call the “Pico” remote, which is a Decora form-factor device that can be paired with a master switch and has roughly the same controls as the master.

So having consistency of control between master and remote switches won out over hating the idea of batteries. That said, the interfaces aren’t completely consistent. The remotes, being battery-powered, don’t have indicator LEDs, and for some reason have an additional button in the middle. It turns out you can get pico remotes that don’t have that enigmatic button, but the Pico that’s included in the dimmer package from Home Depot is this oddball. Either way, the remote, because it runs on batteries, does not indicate dim level, so it’s still inconsistent.

One of these things is not like the others…

Letting go for now, I chose Caseta and was able to wire up all of the controls in my kitchen. The other upside of Caseta is that doesn’t require (or even allow for) a neutral wire. They manage to power the controller in the dimmer from circuit that makes its way through the light. In the end, I had put neutrals in where I didn’t have them, so this wasn’t a necessary feature for me. The only issue I see with this approach is that the operation of the dimmer is dependent on the type of bulbs it is controlling. I had an insidious, non-dimmable, LED bulb in the first circuit I set up. The Caseta dimmer in this case looks like it’s simply not working. The bulb lights up at a relatively dim level and can’t be controlled. It took me some time to root out the problem here.

Smartening

So now I have my lights physically connected and working. The literature from Lutron mentions compatibility with SmartThings, which is the system I set up to talk to my motion and door sensors, so now I set about making the virtual connections.

Two Hubs

The compatibility with SmartThings is not quite what I expected. A SmartThings hub cannot talk to a Lutron switch. Lutron requires their own smart hub to talk to the switches, which in turn connects to my Lutron cloud account, which I can connect to my SmartThings account. What this means is a little troubling; the connection between my door sensors and my lights goes through the internet, so forget about this working if my internet is down. Good thing that never happens…

Two Apps

I set up the Lutron app on my iPhone, and configured my account. I was able to connect and name all of my devices, set up a room, and create “scenes”. Scenes are essentially a state-of-being for a group of devices. You can use them to set the lighting mood in any particular way you want. In my case, the first, and probably only, scene I wanted was “all off”, which can be activated at night to ensure the lights aren’t left on. Creating the scene and activating it from my phone was pretty straight-forward.

Un-Pressable Button

Then I eyeballed that odd center button on the Pico remote. Could I wire that up to activate my “all off” scene? Turns out, yes-ish, if I buy into another home control system from Lutron called “Grafik Eye”. Without that system, which seems like overkill to make use of a single button, the button is pretty much useless. There’s no way to wire it to anything. It’s disappointing that the remote they package with the Caseta dimmer has a non-functional button on it.

Net Gain?

Where do I net-out on this? I did end up with a better wiring configuration without having to completely tear up my kitchen, and I can turn my lights on and off from Alexa or my iPhone.

But there are some surprising learnings here.

First off, retrofitting is hard. You can’t expect wall boxes to be large enough for newer devices, or neutral wires to be available for switches. You’d be pretty lucky if you could upgrade a house’s controls without needing some patching and painting afterwards. It would be great if buildings were constructed with smart components installed at the get-go.

Component interoperability is complicated and unreliable. While I got most of my components to work, it wasn’t without perseverance on my part. Having to have two gateways in my house, loosely connected through the Internet makes me uneasy.

There is a lot of trial-and-error. Something that looks like it will work at first often surprises you when it doesn’t.

A final thought: We lack a meaningful set of standards that define how smart devices connect and communicate. There are plenty of examples where industries are thriving because of standards, official or de facto. Ethernet and Internet Protocols keep everything running today. That level of reliable standard, akin to the RJ45 jack and everything it implies, is missing in the smart home. If builders are to adopt smart home technology in creating buildings, it needs to have the openness, durability, and robustness of Romex wiring, a technology that has lasted for 100 years.

Jim Baldwin

Written by

CEO, Antimatter Research. Silicon valley veteran in hardware and software for consumer products.

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