Yesterday afternoon I caught two interesting/funny service alerts posted at mta.info. The first one mentions Bowling Green-bound (5) trains, when (5) trains go all the way to Flatbush Av. Oops. The second one describes a low power condition at Grand Av. What’s a “low power condition”, what causes it, and how does it actually affect the trains or signals?

Oops: should say Flatbush Avenue-bound

What's a "low power condition"???