Installing TED (The Energy Detective): a tale of two cultures

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:

Step 3.

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.


  1. I’ve been wanting to do this for a long time. Which exact TED model did you buy, and why? I could figure it out on my own, but it’s easier just to ask you. :-)

  2. It’s the TED 5000-C. Two current transformers (one for each 120V leg), one MTU to send data, one gateway to receive/retransmit, and one wireless display.

    For $40 more than the 5000-G you get the wireless display. I think it’s worthwhile. The range isn’t great, nor is the battery life, but sitting in the cradle in the living room it provides the all-important continuous feedback in a way that’s visible to everyone moving around in the house.

    For example, I just walked through there on the way to the kitchen, and noticed that we were a couple hundred watts above what I’m learning to expect the baseline to be, given my sense of what’s running in the house. One reason: porch lights on for no reason. The other: oven exhaust fan running for no reason. Flick, flick, 200 watts saved.

    You can also walk around with the display (as far as its range will allow) to turn stuff on or off and see the effect.

  3. I’ve been enjoying my TED 5000 since August. I held off purchasing the wireless display as they provide a great app for the iphone that displays all the live data concisely.

    One thing you may want to consider is pumping your data off to Google’s Powermeter ( as that provides a fantastic charting mechanism for viewing the historical usage.

    There are only two things I REALLY wish would get implemented:

    1. Correlation to outside temperature
    2. Charting of annual usage for tracking seasonal variations

    Have fun with the new toy!

  4. they provide a great app

    Yep, I was going to mention that a phone will be the best handheld interface. But the energy display on the phone is not visible to everyone all the time. I think that’s going to be very important.


    1. Correlation to outside temperature
    2. Charting of annual usage for tracking seasonal variations

    I’m thinking that kind of stuff will be pretty straightforward to DIY, by pulling data out of the gateway using its dead simple API. Once I’ve got a healthy gateway we’ll see if that’s so.

  5. Jeez, you sure don’t make it sound at all easy to install! I’m certainly interested, but will do an awful lot of reading first to make sure I think I can handle the installation. Thanks for the warnings though, I guess :-)

  6. Paul,

    It really is pretty easy. At its most basic, the instructions are:

    1. Hit the BIG breaker to cut power to the whole house.

    2. Place each clamp around the two main lines feeding the panel.

    3. Connect the black wires into two separate breakers (one for each phase). Typically these would be next to each other vertically.

    4. Connect the white wire to the bar where all the other white wires are connected.

    5. Turn on the power to the house

    6. Plug the gateway into an outlet and connect to your router

    7. Browse to the gateway to ensure it is reporting the full ~120 volts.

  7. It really is pretty easy.

    Yup, that’s a good summary! It would probably be better to just use your seven-point synopsis instead of the installation guide, which raises more questions than it answers.

    However it did force me to start filling in the many conceptual gaps in my understanding of my home’s wiring.

    There are, BTW, assorted YouTube videos about the procedure, both from the vendor and from others. Here’s one I watched:

    A commenter noted that the presenter was using two hands to attach the current transformers, and objected:

    The presenter was clamping his two cables across two live wires with 220V across them. An old electrician taught me as a young kid to always pretend you had one dead arm – you do NOT want 220V across your heart!

  8. Thanks for this post. I’ve been wanting a TED for some time. This whole “authoritative source of my own data” thing has me confused, though. If everyone posts links in forums instead of posting the answers, won’t we just find a huge pile of broken links as web site owners disappear or change their URL structures?

  9. If everyone posts links in forums instead of posting the answers, won’t we just find a huge pile of broken links as web site owners disappear or change their URL structures?

    Not if we regard the links as invitations for cooperating services to syndicate and cache our data managed by our services. In this example, I would grant the forum permission to do that.

  10. Update: Today I received the replacement gateway, plugged it in, the local webserver came right up, everything’s fine now.

    Further update: ahem, not quite, now the gateway is talking fine to my computer but not very well at all to the wireless display, the range has diminished to about 2 feet. However, I called support, they told me my new gateway has newer firmware on the ZigBee daughterboard than the original one did, and the newer firmware has range issues, so they’ll be sending me an even newer version.

    My overall impression:

    – This tech is rough around edges

    – But what it does is really cool and really valuable

    – And they’re working like mad to move it forward

    – And they’re very polite and helpful

    1. Update: Apparently it’s not the firmware on the ZigBee board, but the board itself. They’re sending me a replacement. So, to recap:

      – The first gateway failed.

      – The replacement gateway worked

      – But its ZigBee board failed, so now I’m replacing part of the replacement

      Clearly some quality control problems here. Fortunately they’re quite helpful about addressing them.

      1. I’ll second the comment about there being quality control issues. When I first received my device I had to send it back because the tiny battery inside the gateway was apparently dead. With the dead battery the gateway was unable to remember what time it was which made it unusable for pushing data to google as it was just pushing to Jan 01, 2000.

        I really hope they can get their act together as the product has worked flawlessly ever since I had the battery replaced. I’d hate for others to skip out on such a useful tool simply because of some bad publicity.

  11. Veutility, a local university campus company here in Dublin has developed some interesting technology that identifies the unique energy signature created by each device on the powerline when it powers up.

    By recognizing this signature, it enables much more finally grained measurement of what is using power in a location – often allowing breakdown by specific appliance type (e.g. in the last 24 hours, 35% of my power usage was air conditioning, 10% was electric heater, 20% was computer power supplies, etc).

    They seem to be targetting industrial/commercial power users at the moment, but I’m sure residential applications can’t be far behind.

    (Pretty basic website, but I had an opportunity to see more details on the technology last Autumn and chat to some of those involved; it appears to be the real deal.)


  12. Hi Eddy,

    Nice to hear from you!

    So now that the gateway’s working properly I’m trying out the “load profile” feature which is like what you described. So far I’ve gotten it to recognize the sump pump, but not yet the clothes dryer, it’s a bit fussy, but we’ll see how it goes.

    Clearly we’re headed toward a world in which appliances send this data directly, and can also be controlled remotely. But we’ll have legacy appliances for a very long time, so it’s going to be a challenge to sort out better ways to manage them.

  13. Jon, Does the TED measure voltage and amps to do its calculations or do you need to tell it what voltage you are running?


  14. Jon, in your post, you mention the alternative wiring of the MTU where you attach the black wire to a local circuit shared by the Gateway, and you cap the red wire. Is the wiring for the white wire at all affected by this alternative wiring?

  15. “Is the wiring for the white wire at all affected by this alternative wiring?” No, it still goes to the neutral bus. Caveat: I am Not An Electrician and only vaguely familiar with what that means :-)

  16. Thanks for the update — I would prefer finding something that is just a combination of CTs + Zigbee to integrate with a Digi gateway. The TED might work, but it has more to it than I need. Unfortunately, the utility GE SmartMeter has ZigBee built in, but it doesn’t look like PG&E is going to enable it anytime soon. Once I figure this out, I’ll write it up on my blog.


  17. 120704-2002 EDT

    Your thread is a year old but i think some new comments are needed.

    I have written a set of bound notes on the subject of
    Electrical Energy Measurement, Conservation, & Methods to Reduce Your Electric Bill.

    An outline is at Included at the end of the summary are some graphs of actual data.

    I have additional notes that I just finished on the data structure used on the PLC path for both the 1000 and 5000 systems.

    Some very broad observations to correct some statements in this thread.

    In both the 1000 and 5000 MTUs a Cirrus chip is used to measure RMS current, and RMS voltage from the single current input, and single voltage input. You might think there are two of each of these, but internally there is one of each. Also the instantaneous voltage and current are processed to create an average power measurement over a short time. In the 1000 it is about 1 second. In the 5000 system volt-amperes are calculated in the MTU. Further there is a large accumulator, 64 bits, to store cumulative energy.

    Note: PF (power factor) is defined as Real Power/Vrms*Irms. Incandescent lamps have unity PF, but motors and switching power supplies do not.

    My experience with TED products indicates a quality control problem. Additionally there are design problems. But when working and a knowledge of limitations you can get useful information over a long time. Especially with the simpler 1000 system.

    One limitation is that TED can not be used to prove that a power factor correction capacitor at you main panel does not save you any money. I believe one person claimed TED showed a 5% saving with the power factor capacitor connected. Theoretically there is no saving and using a standard spinning disk type kWh meter you can also show not saving. It takes a very controlled experiment to perform this test.

    Power Line Communication is very unreliable method. But there is a way to possibly get error free transmission. You may not like the approach. It requires a suitable filter and an isolated 120 circuit where only MTUs and an RDU or Gateway are connected.

    The TED 1000 makes measurements once every second. The 5000 once every 2 seconds and later slowing to about a measurement every 5 seconds.

    The 5000 does have the potential for more accurate cumulative energy measurements than the 1000, but problems probably in the Gateway hardware and software may negate this capability.

  18. It is the best time to make some plans for the future and it is time
    to be happy. I’ve read this post and if I could I want to suggest you some interesting things or suggestions. Maybe you could write next articles referring to this article. I want to read even more things about it!

  19. Does the TED show usage on each leg? I’m about to do a home generator setup, and I’d like to be able to see how much juice is hitting each leg so I can balance out consumption when I’m running on generator.

    1. 121114-2241 EST

      No TED does not individually read the two phase currents such that you could extract the information you want. However, there is a way to get the information.

      There is much more to using a backup generator than just getting some steady state values. Of great concern are motors and large incandescent lamp loads.

      I can run 1 refrigerator, 2 freezers, 1 furnace fan motor, 1 washing machine, some lights, a television, a microwave, a toaster oven, and computers from a Honda portable 5 kW generator by doing the correct things. Not all would would be on at once. But I am not particularly limited. Gasoline consumption and noise are problems.


      1. Gordon — I understand the loads — seeing the data on what pulls what when on each leg would be useful. You say there’s a way? What is that way?

      2. 121115-1824 EST

        It is quite obvious. Remove one CT and you will read just one phase. Then replace said CT and remove the other CT. This does not provide simultaneous measurements, but should be close enough for your needs.

        If you want more nearly simultaneous data, then use two 1000 System MTUs. Each MTU with only one CTU. This will provide measurements within about 1 second of each other. The 5000 System has a longer delay of between 2 and 5 seconds.


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