Monday, January 02, 2012

Installing the Energy Detective

It's been an adventure installing the TED 5000 home energy monitor that I got to complement my new solar PV system. (See my Sustainable Adventure blog posts: Solar Powered and Rock Paper Sun.) I'm putting this post on my computer blog because it's more on the technical side. Sorry, it's a long post, I won't be offended if you don't read it. If nothing else, I'm hoping it might help other people with their installations.

I was nervous about installing it in the first place, because I'm not really comfortable messing around in the house breaker box. It didn't help that my last encounter with the house electrical system was when I tried to drill a hole through the back of a closet to run a network cable and managed to hit the electrical wiring inside the wall and short it out. (Annoying Shelley since it left her office without power.) But it's supposed to be straightforward, and I'm supposed to be a technical person. (If I'd been smarter I would have had the electrician install it when they installed the solar panels.)

You have to shut off the main breaker to the house, which means no lights. A headlamp is very handy.

I had to install two MTU's (Measuring and Transmission Units) each with two CT (Current Transformer)  sensors that clamp over the power wires, plus a Gateway unit that connects to your network.

My breaker box has two sections - an upper part with the main breaker, and a lower part with all the house breakers. I assume the idea is that you shut off the main breaker and then you can work in the lower section with no danger. Except I couldn't fit the main CT clamps in the lower section - the only place I could fit them was in the upper section. (where the power is still live on the external side of the main breaker)

I initially only installed the main (usage) MTU because the solar instructions showed two different configurations and I wasn't sure which one I had, which meant I wasn't sure which wires to put the solar CT clamps on, or even if I was supposed to install it in the house breaker box, or outside in the solar breaker box.

Next I had to find an empty power outlet (ideally not too distant from the breaker box) for the Gateway unit. It also had to be close enough to connect to my router. I used the same outlet that my solar panel monitoring unit was plugged into. Both it and the TED gateway use power line communications. (Filling up this outlet didn't make me popular because it was the one that Shelley had been using to plug in chargers for gadgets.)

Of course, my Apple Time Capsule router did not have any more free ports. (I used up the last one for the solar system.) So I had to run out and pick up a switch to get more ports.

Thankfully, I didn't have any trouble with the power line communications, as many people seem to. It probably helps that the office is at the same end of the house as the breaker box. I also remembered reading Jon Udell's blog post about installing a TED. The problem is that some of the TED instructions say to connect the black and the red wires, and some of the instructions say to connect just the black wire. (Not the only issue with their instructions.) Apparently, you should only connect the black one. In which case, why do they have the red one? Are there circumstances when you'd want to connect the red one?

The other thing the printed instructions don't mention is that if you only connect the black wire, then you have to specify that in the configuration. i.e. the default in the configuration doesn't match the instructions, sigh. This issue is fairly obvious because the voltage reads 60 instead of 120 V. Still, it took me a while to discover the setting. At first I assumed I had installed something wrong.

The final step is to connect to the system from your computer. This was a little confusing. It seemed to be a browser based interface, but the instructions also told you to download and run their "installer". I'm always reluctant to install software like this unless I really have to, especially since a lot of the time it's totally unnecessary (like the software that comes with your camera). The instructions said to connect to http://ted5000 with your browser but that didn't work. So I gave in and ran their "installer", which turned out to NOT be an installer at all - it's just a utility that locates the IP address that your Gateway is on.

After all that, it seemed to be functional!

At first, I didn't think it was that critical to monitor the solar system, since it had it's own monitor. But then I realized that I still wasn't really measuring the household energy usage. Instead, I was measuring the "net" i.e. the usage minus the solar generation. And to make it worse, with the default settings for the main MTU, the system assumes that usage will always be positive. But with the solar system, that's plain wrong - when the sun's shining, my usage should be negative, but it was still showing as positive. The reason they do this (absolute value) is so it still works when people install the CT's backwards. (Of course, the instructions don't tell you any of this. I gleaned it from their forum.)

I eventually figured out that I had the first configuration in their solar instructions. I shut off the power and opened up the breaker box again. Eventually I managed to find the right wires in the rat's nest, get the clamps on them, and squeeze them into the box enough that I could get the cover back on. (If it was a suitcase, I'd be sitting on it to get it closed!)

In this configuration my main MTU is configured as "Adjusted Load". What they don't make clear is that this means it handles negative values, which means that suddenly it's critical to have the CT's the right way around. Of course, I had mine backwards. And of course, you don't discover this till you close everything back up and turn the power back on. The instructions tell you to leave the cover off till you verify the system is working, but it's such a tight squeeze getting my cover on, that I feel better doing it with the power off.

Part of the blame for getting them backwards lies in the instructions. The printed instructions that come in the box say to orient the red dots "towards the source of the power". As far as I can tell from my install, that's just plain wrong. The Installation Pictorial on the web site is better - it shows the red dots oriented the opposite way. But the text says to orient the red dots "towards the breaker". That's correct for their picture, but if you ended up putting the clamps on the other side of the main breaker (as I would have if there had been room), then the dots would not be facing the main breaker and the instructions would again be wrong. The video shows the dots the wrong way (AFAIK) and the voice over simply says "make sure you get them the right way", not very helpful.

So I had to reverse the main CT's, which meant opening both sections of the breaker box (you can't take the cover off the top part without first taking the cover off the bottom part) It's easy to put the clamps on the wires, but the main power wires are really heavy and stiff. Although there's a fair bit of room in the top section, it isn't easy to get the clamps turned so the cover will fit back on.

I'm probably overly paranoid, but I did most of this work with rubber soled shoes, gloves, and one hand in my pocket. I'm a belt and suspenders kind of a person, if you hadn't figured that out by now!

It's pretty obvious that getting the CT's backwards has been a common problem - not surprising given their instructions. You'd think by now they would at least have corrected and improved their instructions. They attempted to handle the issue by having the software ignore the polarity in the default configuration. But that just makes it worse in a more complex setup like mine. Why not just add a configuration option to reverse the polarity? I can't see why that would be difficult software-wise. And for customers it would sure be a lot simpler than opening everything back up to physically reverse them. Rather than ignore polarity, the default setup could simply detect the polarity and adjust the setting automatically. Then you wouldn't need confusing instructions about red dots at all.

Finally, I think it's all working properly! Usage shows positive, solar generation shows negative, and the net is either positive or negative depending on whether I'm generating more than I'm using.

In the end I think I turned off the power and opened up the breaker box four times. And every time I turned the power off I had to reset all the clocks in the house.

I didn't bother buying the TED display unit since I knew there were iPhone apps. I've installed the free TED-O-Meter iPhone app which is basic but functional. I bought iTED ($.99) because it had a graph, but the graph doesn't handle negative kW values. I may try some of the others.

One thing I really like about the solar panel system is that I can monitor it from anywhere through the internet. That's because the solar system sends the data to an outside server. The TED system doesn't work that way, instead the data is collected on the Gateway device, which runs a web server so you can access it. That means I can't access it from outside my local network. (Unless I want to punch holes in my firewall and deal with my dynamic IP etc.) It also means all my data is on the Gateway so I'm probably going to lose it at some point e.g. if I update the firmware.

To get around this, the TED system can post the data to an external service. (commonly Google PowerMeter, until they discontinued it.) Unfortunately, this didn't go smoothly. Every time I tried to activate it, it would time out connecting to the server. I tried several different services so I don't think it was a server problem. Eventually I got it to work, but unfortunately I wasn't scientific enough to isolate what the issue was. I tried various combinations of: switching browsers, trying different services, resetting the gateway, entering the url with and without "http://", and turning the OS X firewall on and off. Presumably, it's the gateway sending the data, so my computer and its firewall shouldn't be relevant, but it's possible they have client side Javascript running on the browser that tests the connection during activation.

It's hard to tell which of these third party services is the "best". TED will only post to a single service so I can only try one at a time. I succeeded first with PlotWatt so I'll give them a try. I had emailed them about my connection problem and they responded quickly and helpfully so that's a good sign. The way their system works, they have to collect a certain amount of data before it's functional so I'll have to be patient. Of course, my initial data is a mess because half of it has the wrong polarity!

It would be nice if there were standards for all these home monitoring and automation systems. As it is every manufacturer and every type of system seems to do things differently and none of them work together.

Overall, the TED 5000 systems seems ok. I definitely think they could improve their instructions and documentation. And I think they could simplify installation if they added a polarity option to the software. Personally, I'd prefer if they sent the data to an internet service, but I can see where being able to operate independently could be valuable (e.g. if you don't have an internet connection). I'm glad they use a browser based interface rather than proprietary client software. The user interface is adequate. And it's great that their are third party services and apps.

Overview of my rat's nest.

The main (usage) CT's

The solar CT's in the bottom of the box and the two MTU's mounted outside

Part of the TED display, showing usage of 178w, solar generation of 426w (cloudy), 
with the net result of -248w, negative meaning I'm sending excess power to the grid.


Andrew said...

Sounds like TED needs to hire Penny to whip their install documentation into shape!

notzippy said...

You will have to update this to see how your energy savings have (hopefully) improved

Anonymous said...

I added a piece of cardboard between the wire and the CT so it fit centered and doesn’t float around. Also, I average a part a year failing. On my second unit going into third year. Good luck, Don