LINES GP- 4I0971 - Caterpillar

AEC will reduce the engine speed, when minimal hydraulic demand or no hydraulic demand is present and the engine speed dial is at the 5-10. This action will help to reduce the noise level and the fuel consumption. If the hydraulic system is activated past a load level, the engine speed will return to the setting of the engine speed dial.A signal is sent to the governor actuator in order to reduce the engine speed, when the controller receives a no- load signal for 3 seconds or a small load signal for 10 seconds from a pressure switch in the hydraulic system.The AEC will operate in two modes. These modes can be controlled by the AEC switch. The AEC switch is located on the monitor. The AEC will be set to "AEC ON" mode automatically, when the engine start switch is turned to the ON position. The indicator next to the key start switch will illuminate. The indicator will turn OFF, when the AEC switch is pressed. The AEC is then set to the "AEC OFF" mode.First stage of the AEC Mode With "AEC OFF" - The controller will control the governor actuator directly, when minimal hydraulic demand or no hydraulic demand is requested. The governor lever will be moved to a position in order to reduce the engine speed by a maximum of 100 rpm automatically.Second stage of the AEC Mode With "AEC ON" - The AEC portion of the controller will control the governor actuator. Engine speed is reduced to 1300 rpm automatically, when minimal hydraulic demand is present. The engine speed will be reduced by a maximum of 100 rpm when a small load is placed on the machine.Under a minimal load, the rate of automatic engine speed drop is dependent on the current position of the engine speed dial.If the temperature of the hydraulic oil is low, the engine speed will not be reduced automatically even though the AEC switch is in the ON position. The AEC will not function correctly while the backup switch is in the MAN position. For more information about the operation of the AEC, see Hydraulic System Systems Operation, "Pilot Circuit" in the module for the machine that is being serviced.