Generator and The Energy Detective (TED) Writeup

velvetfoot Posted By velvetfoot, Dec 12, 2011 at 1:15 PM

  1. velvetfoot

    Minister of Fire 2.

    Dec 5, 2005
    Sand Lake, NY
    I thought it'd be neat to see how much power the generator was putting out from the comfort of the house.

    As background, there is an existing TED 1001 ( ) measuring kW, kWhr, Volts, etc - it has provided some entertainment value over the years (and this is all that this project, really, is about). There is a generator inlet on the side of the house that feeds an interlocked 240v breaker on the main panel. I have several generators, with 240v, 120v RV receptacle, and 120v standard receptacle. The generator cable is configured normally to plug into 240v, however, I made up a couple of adapter sets that allow the 120v generators to plug in to the cable. The 120v adapters power both legs so that power is available everywhere in the house, except for the 240v loads.

    I originally tried to get two current transformers (CT), that clamp around the current-carrying supply wires, but I was able to get a brand new TED 1001 for $75 (spare display now, I guess). The TED 1001 supposedly isn't meant for more than one set of CTs, but in the setup screen there is indeed an option for 2 sets. While powering the house with 120v, I fooled around with the placement of the CTs on the wires for a while because the power readings didn't agree with the kill-a-watt at the generator. It turned out that when I reversed one of the CTs (so that the dots painted on them weren't facing the same direction) the readings matched. I guess one has to choose whether you want to read a 240v or 120v generator supply; I chose 120v.

    So now, there a two sets of CTs and associated power line carrier transmitters inside the panel, and the display upstairs reads line info normally and 120v generator in an emergency. Again, mostly for entertainment value.

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