The large dial at top center appears to be the "synchroscope" which is necessary to "synchronize" the generator uoyput to the main system. If you throw the switch at the wrong time, you could blow up the generator. Not a good thing to do!

These appear to be "MG" (motor generator) sets that supply "exciter current" to the brushes in the main generators. They are found in all power plants.

I'm a "retired" Power System Operator. Imagine being here in an electrical storm with circuits "tripping" and trying to run back and forth keeping track of all this without computers! I really enjoy this series---glad I stumbled across it!!