Rewiring The Power Shed

Things got interesting last winter, when the old Honda generator shorted something out, and went way off frequency. By itself, that wouldn't have been too bad, but in this case, it fried the old Heart Inverter in the process. Suddenly, the inverter wouldn't idle anymore, and became a huge phantom load, all by itself. It had also taken to making this weird buzzing sound... The day everyone woke up and the batteries were down to 9.6VDC, I knew a big project had come.

Once I came to grips with the fact the inverter was toast, I decided I might as well go all the way, and rewire the power shed while I was installing the new inverter. I had always wanted to do this "someday", but I guess that is now... Anyway, I broke down and bought a Trace 4024 from Joe Callahan of Simple Solar of Boulder, CO, along with a Trace DC250, breakers, a lightening arrestor, and a new Solar Boost 50

Initially I just replaced the inverter in a quick manner, while planning the next step. I figured it was about a 3 day project with two people. The old system was pretty ugly, with only one disconnect, and some pretty scary wiring in places. This was my opportunity to improve the situation. To help ensure this actually got done in 3 days, I decided to enlist the help of Drake Chamberlain, who not only if working on his own Solar Lab, but also used to live in these domes about 10 years ago. :-) Conveniently, Drake is an old friend, and master electrician.

We started on a decent day in late April (decent for this altitude, anyway), and started by ripping all the old breakers, junction boxes, everything off the wall. Now we were committed. We first shortened the old conduit from the house to the power shed, so the new junction boxes would be closer to the ground. We wanted as much space on the wall as possible for the inverter.

Then we started assembling the DC 250, and installed it on the wall. Moving the inverter was interesting, cause it's heavy. Drake has a bad bad, so I had to leverage the thing into place by myself, and Drake then bolted it to the wall. We managed to get it into place on the wall next to the DC250, and wired up power from the batteries to the inverter. The I turned the house AC back on, and we called it a day as it had started snowing pretty heavily, and was getting colder. There wasn't any direct DC power in the house (most of the light are 24VDC), but there are enough plugin AC lights to get through the night. Life in the middle of a big project...

The next day was spent dealing with lots of new breaker boxes and junction boxes. The main idea behind this rewiring project was to bring everything up to code. So before where there was one giant disconnect for everything, there was now literally a new disconnect for everything. We added several new junction boxes, to keep the AC and DC power systems separate, as well as the generator separate from the inverter. Then to make things interesting, we also wanted to wire the old Gen-Charger in, so I could use it as well as the trace to charge the batteries. In fact, using both is a good idea, cause now it pulls on both phases of the 240AC output from the generator.

After checking in the wind, we determined the old Whisperlight wind generator was dead as I suspected, so we blew off wiring that in. Instead, we used that 60A breaker for the Gen-Charger, and the other 60A breaker in the DC250 went towards the photovoltaic panels. We got the Solar Boost wired in, although in the dark we couldn't tell if it was working or not. By this point we were working by head-light anyway.

The weather was now getting truly shitty by afternoon. Windy, some snow, and cold... It froze the water jugs I had brought to top off the batteries. We worked on it till pretty late, but got AC and DC power fully back on finally. Lots of wiring... but there was now an AC breaker box, a DC breaker box, AC outlets, disconnects everywhere, and tons of conduit. At the last minute, we wired in the lightening arrestor, and stopped for the day.

The third day was mostly wiring in the generator, rewiring the battery bank some, and lots of little projects. Rather than running the generator cable across the floor, which was why it shorted out in the first place, we ran conduit all the way around the door, and wired the generator through that. Now it is safely out of the way. The generator was wired up to feed both the Trace and the Gen-Charger, all properly protected by breakers. There are now disconnects for all the different circuits, and conduit was used everywhere.

Part two of this 3 phase project was replacing the batteries, and building a battery box with some heat. That project is described here.

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