Alternating current generator

An AC generator configured to output power at a plurality of different power specifications when driven by an engine, the AC generator comprising:

• a plurality of armature windings;
• an output terminal connected to the plurality of armature windings and configured to output electrical power;
• a remaining power controller configured to calculate a safe remaining output capacity value of the AC generator for each of the plurality of different power specifications based on an output voltage value measured at the output terminal and an output current value measured at the output terminal;
• a display configured to display the safe remaining output capacity value for each of the plurality of different power specifications;
• wherein the remaining power controller includes a processor configured to:
• calculate a remaining apparent power output capacity value for each of the plurality of different power specifications based on the output voltage value and the output current value;
• calculate an active load power value for each of the plurality of different power specifications based on the output voltage value and the output current value;
• calculate a remaining active power value for each of the plurality of different power specifications by subtracting the respective active load power value from a rated output of the engine;
• and
• compare, for each of the plurality of different power specifications, the respective remaining apparent power output capacity value to the respective remaining active power value and output the lower value as the safe remaining output capacity value.