Friday, March 21, 2008

EnerSure Installation Tips

After Ethan's last post explaining the details of the installation process, I thought it would be a good idea to summarize some of the lessons we've learned so far.
So here's a summary of what we learned from the new EnerSure installation on the 123 wing of Porter Hall:
  • Besides physical space and easy access to the individual circuits in the electric panel, here are the other most obvious requirements for installation:

    • Network connection (a cable from the EnerSure unit to a network outlet)

    • Power supply (a power outlet for a three-prong adapter that powers the unit)

    • Make note of the MAC address of the Digi Connect ME serial to ethernet adapter that comes in the processor module of the EnerSure.

    • Make sure there are enough data gathering modules for all the circuits that will be measured from the panel.

    • Configure the jumpers in the data gathering modules according to the phases in which the circuits are in the panel. Also set the jumpers that number the different data gathering modules accordingly.

  • Do the last three steps before assembling all the modules together. Only after making sure it is all correct, you can put them together.

  • Test the unit before mounting it. Run the latest version of TPConfig over the network, setup the unit via this software (ModBus address, CT type, circuit phases, etc).

  • Run your logging daemon (in our case thermd) and make sure it works (also before mounting the unit and connecting the CTs). The latest version of thermd allows us to specify the ModBus address for the unit, which was a source of problems.

  • Label all the CTs with numbers on both ends of the wire.

  • Mount the EnerSure, connect all the cables, and power it up.

  • Listo.

Wednesday, March 12, 2008

Bringing the 123 wing Enersure online

After a long installation process, the new Enersure electricity meter has finally connected to the circuit breaker panel in the Porter Hall 123 wing. This involved installing a new steel box over the breaker panel, connecting the two enclosures with conduit (inside the cinder block wall), mounting the Enersure in the new box, pulling CT cables through the conduit, wiring the voltage transformer into a 3-pole breaker (since it's a 3-phase panel), and installing a 110V outlet outside the box (for the Enersure's power supply). We estimate that this took over 100 hours of electrician labor: once the box was installed (in October) it took Joe--often working with Dave, his assistant--the better part of a week to get everything wired up.

One installation issue that might be re-addressed for the next panel is how the Enersure unit is connected to the back of the box. The Enersure is mounted on threaded posts: mostly male/female, but some f/f are available to reverse the "polarity" of the stack. In this way, it's possible to attach the top board with phillips-head screws and still have female thread on the bottom of the stack. For this installation, Joe mounted threaded posts to the back of the box, then secured two rails to the posts with fender washers and nuts. Before securing the rails to the posts, he screwed the Enersure to the rails from the back. It's now possible to remove the Enersure-on-rails assembly by removing four nuts, then unscrew the rails from the Enersure. However, the screws used to attach the Enersure to the rails were the wrong thread pitch, and I believe that they were originally installed by force--effectively re-tapping the threads in the bottom posts! In the future (if we use this mounting system again) we should be sure that there are enough of the correct screws to attach the Enersure without damaging any of the mounting hardware.

Once those pieces were all physically installed, we started wiring up the Enersure. This can be a bit of a challenge if one forgets a step before moving on, as each board must be physically configured before the next board is attached to the top of it. The MAC address is labeled on the ethernet port, but must be recorded before the next board is attached. Each metering board (the first/bottom board is the CPU and communication board) must have a jumper set to indicate its order in the stack, then jumpers for each channel to indicate the phase of the circuit they are measuring. Finally, the boards are all connected to a single ribbon cable. I think that the Enersure is implicitly grounded by the way it's connected to the box, which is grounded, but if that's not adequate we should add a ground wire to one of the mounting posts.

Then it was time to try communicating with the Enersure over the ethernet cable that had been run through the ceiling into Scott's office. Though the MAC address of the device had been registered with CMU's netreg system and it had been assigned a static IP address, the default DHCP settings on the Enersure were not adequate to get it working on the network. It turned out to be necessary to first connect to it with the TP Config (www.bitbox.co.uk/trendpoint), but first it's necessary to run the Digi Port software (which establishes a virtual serial port over a crossover ethernet cable, or through a router in our case). This allowed us to indicate that it should communicate via the ethernet connection, not the serial port. It also configured the board with the correct phase for each channel, as well as indicating which channels were coupled on 2- and 3-phase breakers. We did see some errors on the OEM calibration screen, indicating that (for most of the channels) there is a cct or wiring error; I need to record the exact wording, but I'm hoping that it's a matter of reversed CTs and we will also be able to detect that in the data where there are channels with >0 Watts but 0 amps.

Getting the ethernet card working on the network took still more steps. First I logged into the built-in server on the Enersure and changed the DHCP settings to use a static IP address instead. Since the subnet that it was assigned to is configured a little funny (subnet mask of 255.255.240.0), I guessed the router address wrong. I finally figured it out by spoofing the MAC address on my MacBook Pro, choosing to connect to the ethernet port (en0) using "DHCP with static IP" and then recording the router IP and subnet that it was assigned, finally transferring those to the Enersure. Note that this was a nasty mistake to make, because I wasn't able to connect to the Enersure again as easily once I had changed the IP address to the wrong one; I had to configure the router between the laptop and the Enersure to the router address I had entered on the Enersure, then change the laptop to be on that same (bogus) subnet.

Now that the Enersure is finally working on the campus network, I'm not sure it's possible to use TP Config to adjust the setting as easily; I wasn't able to get the Digi Port software to see the device. If necessary, I will have to restore the Enersure to using DHCP and re-connect it directly to the Windows laptop in order to play with those settings.

However, at this point I'm simply going to try to get the thermd config file to see the new Enersure and get some data in the database. From there we should be able to see which CTs need to be flipped and then the data collection can begin in earnest!