It wasn't. They were feeding generators 1 & 2 with the pump intended for flushing the lines while switching between different fuel types.
The regular fuel pumps were set up to automatically restart, which is why a set of them came online to feed generator 3 (which automatically spinned up after 1 & 2 failed, and wasn't tied to the fuel-line-flushing pump) after the second blackout.
The regular fuel pumps were set up to automatically restart, which is why a set of them came online to feed generator 3 (which automatically spinned up after 1 & 2 failed, and wasn't tied to the fuel-line-flushing pump) after the second blackout.