When I wrote about my experience with the Kill-A-Watt, commenters alerted me to the next level in the real-time power monitoring game: gadgets that watch the whole house instead of one appliance at a time. Back then the only solutions I could find were for UK power systems, not US power systems. But recently I found The Energy Detective and ordered a TED 5000 straightaway.
The bottom line is that it works. I’ve got a real-time display showing how many watts my house is burning at any given time, along with the equivalent hourly cost. When I turn off lights or appliances that don’t need to be on, I can see the difference. There’s much more data available, but continuous instant feedback is the essential thing. It’s a powerful behavior changer.
Unfortunately my TED system isn’t yet working as well as it should. One of the components is ailing. It’s the gateway that receives data from the transmitter I put in my distribution panel, and sends it along to the wireless display and to my LAN. The gateway’s local webserver won’t respond to requests, and the gateway’s connection to the wireless display is flaky. So I’ve ordered a replacement. I hope it’ll work properly, and if it does I’ll have more to say about the software aspects of the TED. But meanwhile, this is a good time to talk about the basic hardware setup. It’s pretty straightforward, but I think the vendor, Energy Inc., explains it misleadingly. That’s a shame. I hope lots of people will be able to use this remarkable tool, and I want them to have good experiences with it. So here’s what I think Energy Inc. does wrong with its installation guide, and how I think it could be improved.
The guide says:
A technically-savvy homeowner, neighbor, friend or electrician can install TED in 10-15 minutes.
And that’s true. But there are different ways to be technically savvy. The TED is a mashup of two different technologies: electrical distribution and data networking. Each has its own set of concepts and associated terminology. An electrician may know little about data networking. A homeowner like me may know a lot about data networking but very little about electrical distribution. A map of concepts and a glossary of terms would be really helpful.
On the electrical side, the terminology includes 120/240V single-phase, A phase, B phase, two-pole breaker, and handle tie. If you’re an electrician it won’t occur to you that the terms single-phase, A phase, and B phase will confuse somebody who isn’t an electrician. Like me. If it’s a single-phase system, I wondered, how is there an A phase and a B phase? I had to consult Wikipedia’s article on split-phase electric power:
A transformer supplying a 3-wire distribution system has a single-phase input (primary) winding. The output (secondary) winding is center-tapped and the center tap connected to a grounded neutral. This 3-wire system is common in countries with a standard phase-neutral voltage of 120 V. In this case, the transformer voltage is 120 V on either side of the center tap, giving 240 V between the two live conductors, shown as V1 and V2 in Fig. 1. The two outputs are properly called “legs”, not “phases”.
Ah. Now I could see why the TED’s MTU (measuring transmitting unit) needs (I wrongly thought) to be connected to the A “phase” and the B “phase” — all the wiring in my house is divided into two “legs” and the MTU (I wrongly thought) needs to reach both of them. Here’s the recommended procedure:
A.) Connect the black and red wires from the MTU power cord to a spare 15, 20, or 30 amp two-pole circuit breaker.
B.) If there is no spare circuit breaker in the panel, it can be attached to any 15, 20, or 30 amp two-pole breaker in the panel. If a two-pole breaker is not available, then use an approved handle-tie to create one.
At this point, as a data-network-savvy but electrical-distribution-naive homeowner, I’m ready to call in an electrician. It’s lucky I didn’t, though, because a data-network-naive electrician would likely have missed the significance of this cryptic remark stuck in between steps A and B:
(Option: For increased signal strength, connect only the black wire.)
Huh? Oh. Now my data networking knowledge kicks in. The MTU uses power line networking. That means it sends data over electrical wiring. Where does it send data? To the gateway, a little box that plugs into an outlet somewhere and talks to the wireless display and also to a computer or, if you run a local area network, to your Ethernet router. The recommended place to plug in the gateway is an outlet near your router, so you can control it and read data from it using any computer on your LAN.
The instructions tell you to connect the MTU to both legs of your electrical distribution. In theory that enables you to plug the gateway into any outlet in the house. In practice, as you’ll find if you try, fail, and then consult the troubleshooting guide, probably not.
But now I began to see that you don’t need to do that. You could connect just one of its wires to one breaker that controls an outlet near your router. And in fact that’d be better, because power line communication can be flaky and you want to use the most direct signal path. (The outlet should preferably be near your router but not actually on a circuit that powers noisy devices like the router, or computers, or the TV. And I found one that met that requirement.)
I found confirmation for this direct approach in the troubleshooting guide:
3.7. Considering the factors affecting PLC communication, if the Gateway is still not receiving a signal, do the following:
3.7.1. Connect the black wire of the MTU to the circuit on which the Gateway is connected.
3.7.2. Remove the red wire from the circuit in which it is connected, and put a wire nut onto the red wire.
Further confirmation came from the tech support guy I spoke with when I reported the sick gateway. “Yeah, I don’t know why the manual says to use a spare two-pole breaker,” he told me. “A lot of times that doesn’t work, then people call me up and I tell them to do it the way you did.”
Documentation that spelled out the concepts and terminology in each domain, and the relationships between the domains, would help people grounded in one or the other of the domains see the whole picture.
On the data networking side, the terminology includes PLC (power line communication), Ethernet, and ZigBee. There are actually three kinds of data networking happening. The MTU talks PLC to the gateway. The gateway talks Ethernet to your computer or, if you’re running a local area network as many now do, to any computer on the LAN. And the gateway talks ZigBee to the TED handheld wireless display. All this was obvious to me, but might not be to an electrician or electrically-savvy homeowner. Spelling out concepts and terminology would help that person sort out what gets distributed where:
- Electricity to the whole house, via the two legs of the power system
- Data to the gateway, via the electrical wiring
- Data to/from a computer or router via Ethernet cable
- In a LAN situation, data to/from one or more computers via Ethernet cable and/or WiFi
- Data to the wireless display via ZigBee
Maybe a lot of this context was provided by other TED users in the support forum. Except, oops:
Several weeks ago our Forum Server crashed, and we were unable to recover the valuable library of comments that our users had posted over the prior year.
Those forum members have now learned, the hard way, to appreciate the first of the seven ways to think like the web:
1. Be the authoritative source for your own data
The Energy Inc. site goes on to say:
Our new Forum Server has built-in safeguards to prevent the loss of data should there be a hardware malfunction. We do encourage those of you who have been avid online supporters to please continue to assist those new TED users in their quest to become experts!
Sure, happy to do it, but not by posting this article to the forum. Instead I’ll invoke the second Thinking Like The Web principle:
2. Pass by reference not by value
I want this article to help new TED users. Maybe somebody in the new forum will link here. Maybe I’ll do it myself if I can be bothered to create Yet Another Account. But even if that doesn’t happen, there’s an implicit connection via search. Anybody searching for key terms in this article, along with TED 5000, will land here.
I’m glad the forum server has backup now. But I still don’t want to commit a lot of my own keystrokes to somebody else’s cloud database. I want to keep those keystrokes in a cloud database that’s accountable to me, and then link them to wherever else they need to show up.