PLATE-WEAR 4416135 - Caterpillar

Backup Circuit Schematic (In Backup Operation)
(1) Controller. (2) Governor backup switch. (3) Governor actuator. (4) Governor actuator drive circuit. (5) Speed change switch. (6) Pump backup switch. (7) Proportional reducing valve. (8) Proportional reducing valve drive circuit. (12) Backup signal. (13) Backup signal. (14) Backup resistor.Governor backup is activated by governor backup switch (2) and speed change switch (5). With governor backup switch (2) in MAN (backup) position, move speed change switch (5) backward (to rabbit sign position) to increase rpm and move it forward (to tortoise sign position) to decrease rpm. Releasing switch (5) causes the machine to maintain the engine speed as it was just before being released. The governor backup overrides the function of the engine speed dial.The above schematic represents the backup condition with governor backup switch (2) in "backup" position and speed change switch (5) in the acceleration position. Governor actuator (3) is disconnected from its drive circuit (4) but directly activated by speed change switch (5). Controller (1) receives only backup signal (12) of "backup status" from speed change switch (5).Pump Backup
320 Controller Compartment (Rear Of Cab)
(1) Controller. (15) Controller indicator.
325 Controller Compartment (Machine Right Front)
(1) Controller. (15) Controller indicator.
330 Controller Compartment (Machine Right Front)
(1) Controller. (15) Controller indicator.When a problem occurs in the pump control portion of the controller, controller alert indicator (10) or monitor alert indicator (11) illuminate, or controller indicator (15) turns yellow or red. When this happens, pump backup should be activated with pump backup switch (6). Move pump backup switch (6) backward (to tortoise sign "backup" position). This disconnects proportional reducing valve (7) from the controller circuit (8). Proportional reducing valve (7) is supplied a constant current flow through backup resistor (14), and pump backup switch (6) which causes the constant power shift pressure to regulate the pump. The controller receives only a backup signal (13) of backup status.During pump backup operation the character display shows the following indication. H : when pump backup is used alone.U : when both pump and governor backups are used simultaneously.Governor Lever Control By Engine Speed
Illustration Of Controller Inputs To Outputs For Engine Speed Control (Partial)
(1) Monitor. (2) Controller. (3) Speed sensor. (4) Engine. (5) Engine speed dial. (6) Travel pressure switch. (7) Implement swing pressure switch. (8) Governor actuator. (9) Feedback sensor.An exact engine speed control is performed by the combined operations of the components shown in the above illustration. A failure in only one of them could result in improper engine speed control.This section describes the engine speed control only when there is a problem in feedback sensor (9) and/or its circuit. During a normal condition, the controller controls the engine speed based on the signal sent from