INSERT 2298570 - Caterpillar

Work Mode Switch
Push this switch to select a work mode. On earlier excavators, whenever the engine start switch is moved to ON from OFF, the work mode is always set at the Boom Priority mode. Select a suitable work mode position, depending on the type of work to be done.On later excavators, whenever the engine start switch is moved to the ON position, the work mode remains the same as it was before the engine start switch was turned to the OFF position. Select a suitable work mode position, depending on the type of work to be done. Boom Priority Mode (1) - This gives hydraulic flow priority to the boom circuit. It is intended to provide very fast boom up speeds in applications such as truck loading and deep trenching where the boom up time is a major portion of the total cycle time. This is the preferred mode in most digging applications. Swing Priority Mode (2) - This gives hydraulic oil flow priority to the swing circuit. Since hydraulic flow from one of the two main pumps is guaranteed to the swing circuit, swing crowd will be smooth and consistent regardless of what other hydraulic functions are used. This mode is best in applications where smooth trench or excavation walls are required or in situations where swing angle is 180 degrees or more. Fine Control Mode (3) - This limits flow to the stick-in circuit to one pump. Normally, flow from both pumps is available to the stick-in circuit for fast stick-in times. In Fine Control Mode the stick-in function is limited to one pump flow, making stick-in slower and more controllable. This mode is most when finishing a slope, fine grading or in lifting applications.Automatic Engine Speed Control (AEC)
The automatic engine speed control functions to automatically reduce engine speed when there is no hydraulic demand or when the hydraulic demand is very small. The purpose of the AEC system is to reduce fuel consumption and noise.The system will be inoperable while the governor control system backup switch is in the MAN position. (If the hydraulic oil is not at normal operating temperature, the AEC may respond slowly.)The AEC system operates in the following three levels, depending on the position of the AEC switch and the operation of the manual low idle switch. In any condition, the engine rpm will recover automatically to the engine speed dial setting upon the activation of any hydraulic function.Level One:
* AEC switch OFF* Manual AEC system not activated* Engine speed dial in a position from "5" to "10"The electronic controller automatically reduces engine speed by 100 rpm approximately three seconds after there has been no hydraulic demand.Level Two:
* AEC switch ON* Manual AEC system not activated* Engine speed dial in a position from "5" to "10"The AEC system in the electronic controller will automatically reduce the engine rpm to around 1300 rpm approximately three seconds after there has been no hydraulic demand.Level Three:
* AEC switch ON or OFF* Manual AEC