Systems and apparatuses include a control unit structured to communicate with a first generator set, a second generator set, and a third generator set, operate the first generator set as an output generator in an exercise mode, and operate the second generator set and the third generator set as load generators in the exercise mode to use electrical power produced by the first generator set. The second generator set uses a second genset portion of the electrical power and the third generator set uses a third genset portion of the electrical power.