AIR INTAKE SCREEN DEBRIS SENSING

An air intake screen debris cleaning system may include an intake screen through which air is drawn in a first direction for cooling, a reverse airflow generation system to create a reverse airflow in a second direction opposite the first direction to clear debris from the intake screen, a sensor to sense debris that is collected on the intake screen and a controller to activate the reverse airflow generation system based upon signals from the sensor. In one implementation, the sensor comprises an emitter to emit a sensor beam that extends along a face of the air intake screen and which does not intersect or pass through the air intake screen prior to being sensed.