Control system for a generator

A method of controlling a generator set for a transport refrigeration unit operable at a first frequency and a second frequency, the method comprising:

• providing a generator and a prime mover coupled to the generator;
• driving the generator with the prime mover in least at one of a first non-zero speed and a second non-zero speed;
• sensing a load of the generator using a sensor and delivering a signal indicative of the sensed generator load to a controller in electrical communication with the prime mover and the generator;
• and
• selectively varying the speed of the generator between the first speed and the second speed with the controller in response to the sensed generator load.

A generator set for a transport refrigeration unit, the transportation refrigeration unit operable at a first frequency and a second frequency, the generator set providing electrical power to the transport refrigeration unit, the generator set comprising:

• a housing;
• a generator disposed in the housing and configured to provide electrical power to the transportation refrigeration unit;
• a prime mover disposed in the housing and coupled to the generator to selectively drive the generator at least at a first non-zero speed and a second non-zero speed;
• a controller in electrical communication with the generator and the prime mover;
• and
• a timer in electrical communication with the controller, the timer operable to determine a duration of time that the prime mover drives the generator at the first non-zero speed, wherein the controller is operable to change the prime mover from operating the generator at the first non-zero speed to operating the generator at the second non-zero speed based on the duration of time determined by the timer.