[blackdog]

Uhh....yes! Pretty dangerous if you don't! Think Fukushima.

Controls voltage is what controls the (Machine name here). If there is a problem with the generator, reactor, or turbine, and systems need to open/close valves, produce compressed air for pneumatic valves controls, pump lubricants, pump hydraulic fluids, and control speeds, you're in deep doo-doo without control voltage.

Or here's an easier way to understand. "How do you start a generator turbine when the turbine isn't running"? How do you open and close circuits, run pumps, and governors, when the turbine hasn't started yet?

[monkeyshine]

No I get it. I work with machines of a different sort but they all have control panels to adjust different variables like speed, angle, pressure, cycles, trigger delay etc.

Makes sense that you need the control panel powered up to power up the power turbine generator. It just sounds bizarre. And you couldn’t really put them in series either you’d still need at least one power source to start the entire “farm” even if you could harness one to power up the next. With windmills I’m just guessing you need to control start/stop, angle of the turbines, gears, maybe rotation and motorized pivot to turn the entire mill towards the optimal wind direction - just off the top of my head. Probably 100 other things like sensors and safety triggers etc - things I don’t know since its out of my realm of specific expertise.

[Don W]

Fukushima was a huge anomaly.

The generators had fuel enough to run for weeks, but those tanks were washed away in the tsunami. The battery backup for the gensets worked exactly as designed and kept everything under control until the battery banks ran out of juice.

Nobody anticipated that there would not be power available for over three DAYS, let alone the weeks it took to get power there. Had the diesel tanks not washed away, we wouldn’t be having this discussion, it would have been a non-event.

[blackdog]

We had several gearboxes driving 25,000 pound drive shafts at 4,000 RPM. Some nitwit didn't follow the unlock from lockout procedure to the letter. He was in a hurry. He forgot to energize the oil pumps to the boxes and started the main machine up. They heated up in excess of 3,000 degrees, went white hot, and caught everything around them on fire. The fire couldn't be put out because the water would have made the cast gearboxes explode. Each gearbox was about the size of a utility van.

The main machine can't be stopped once it's at speed because it takes a half hour to stop. Any faster and you'll rip the footings right out of the foundation and have a steam loaded Yankee Dryer rolling down the nearest highway at 6,000 feet per minute. (about 60 miles per hour)

I immediately installed prove oil flow sensors into the start circuit. An example of auxiliary control circuits and their importance.

[ProtectOurFreedom]

“Black start” of any power plant is the same.