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| Illustration 1 | g06121698 |
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(1) Machine ECM
(2) Operator Monitor (3) Engine speed dial (4) Engine ECM | |
Machine ECM (1) receives the engine speed dial (3) signal from the soft switch panel. The machine ECM then transmits the desired engine speed to the engine ECM. The position of the engine speed dial is indicated on operator monitor (2). The machine ECM, engine ECM, and soft switch panel ECM communicates these signals via the CAN data link.
Engine speed dial (3) is a 10-position switch. The selected position is displayed on operator monitor (2). The desired engine speed for each dial position can be changed in Cat ET. The hydraulic torque settings for each dial position can be changed in Cat ET or through the monitor.
Note: The actual engine RPM and torque output will vary, depending on the setting of the power mode that is selected. The standard mode and economy mode will change to high hydraulic power mode during travel.
| Corresponding Engine rpm and Torque Output for Each Engine Speed Dial Position (No Load Condition) | ||||||
|---|---|---|---|---|---|---|
| Engine Speed Dial Position | High Hydraulic Power Mode | Standard Power Mode | Economy Mode | |||
| Engine rpm | Torque Output (%) | Engine rpm | Torque Output (%) | Engine rpm | Torque Output (%) | |
| 1 | 900 | 42.0 | 900 | 42.0 | 900 | 42.0 |
| 2 | 1000 | 51.0 | 1000 | 51.0 | 1000 | 51.0 |
| 3 | 1100 | 62.0 | 1100 | 62.0 | 1100 | 62.0 |
| 4 | 1200 | 72.0 | 1200 | 72.0 | 1200 | 72.0 |
| 5 | 1300 | 84.0 | 1300 | 79.0 | 1270 | 79.0 |
| 6 | 1430 | 88.0 | 1430 | 79.0 | 1330 | 80.0 |
| 7 | 1570 | 91.0 | 1570 | 79.0 | 1380 | 81.0 |
| 8 | 1650 | 92.0 | 1650 | 81.0 | 1430 | 82.0 |
| 9 | 1720 | 93.0 | 1720 | 84.0 | 1570 | 86.0 |
| 10 | 1800 | 100.0 | 1800 | 93.2 | 1600 | 88.1 |
Machine ECM (4) is a self-diagnostic component. The machine ECM monitors the inputs and the outputs. The machine ECM monitors the system problems that can occur and system warnings that are generated during the operation of the machine. The machine ECM will display a system warning that is generated, or a problem that has been detected, via the self-diagnostic function on operator monitor (2).
Note: A log file is kept for the warnings. The log file contains the time and the number of occurrences of each warning.
Automatic Engine Speed Control (AEC)
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| Illustration 2 | g06121700 |
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(1) Machine ECM
(2) Operator Monitor (4) Engine ECM (5) Switch Panel (6) Pump 1 Pressure Sensor (7) Pump 2 Pressure Sensor (8) Implement Pressure Sensor | |
The Automatic Engine Speed Control (AEC) automatically reduces engine RPM when the machine is inactive. The AEC system is designed to reduce fuel consumption and noise. Lower engine speeds can also increase engine life.
The engine rpm will recover automatically to the setting of the engine speed dial when any hydraulic function is activated. The AEC system operates in three modes. Refer to Table 2 for a description of each mode.
Hydraulic demand is detected by either the implement pressure sensor, the travel pressure sensors, or the pump discharge pressure sensors.
Note: Input components related to the tool control system can detect hydraulic demand as well.
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| Illustration 3 | g02624857 |
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Automatic Engine Speed Control (AEC) Selection Switch | |
The Automatic Engine Speed Control switch is activated when the engine start switch is turned to the ON position. The indicator lamp will turn on. When you press the AEC switch, the function of the AEC switch changes from ON to OFF. The operator can choose from three possible modes for automatic engine speed control. Refer to Table 2 for more details.
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| Illustration 4 | g03876297 |
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One Touch Low Idle Switch (RH Joystick) (10) One Touch Low Idle Switch (RH Joystick) | |
Activate the manual low idle in order to reduce the engine speed to approximately 900 rpm. Pressing the switch again will allow the engine speed to return to the original setting of the engine speed dial.
The manual low idle allows the operator to reduce the rpm without touching the engine speed dial. This action is useful when the operator wants to reduce the engine speed in order to talk to someone or while the operator is waiting for a truck.
Operation of the automatic engine speed control depends on the position of the AEC switch and of the switch for manual low idle. The engine rpm will recover automatically to the setting of the engine speed dial when any hydraulic function is activated.
| AEC Mode | Position of AEC Switch | Setting of Engine Speed Dial | Position of Manual Low Idle Switch | Description of Mode |
|---|---|---|---|---|
| First stage | OFF | 3 to 10 | OFF | The electronic controller automatically reduces engine speed by 100 rpm after there has been no hydraulic demand for approximately 5 seconds. |
| Second stage | ON | 3 to 10 | OFF | The AEC system in the electronic controller will automatically reduce the engine rpm to approximately 900 rpm after there has been no hydraulic demand for approximately 5 seconds. |
| Manual low Idle | ON or OFF | 3 to 10 | ON | The engine speed is reduced to approximately 900 rpm. |
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| Illustration 5 | g06121702 |
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(1) Machine ECM
(2) Monitor (4) Engine ECM (5) Switch Panel (6) Pump 1 Pressure Sensor (7) Pump 2 Pressure Sensor (8) Implement Pressure Sensor (9) Swing Control Pressure Sensor (10) One Touch Low Idle Switch (RH Joystick) | |
When one-touch low idle switch (10) is pressed, and the machine is not under load (all levers and pedals in the neutral position), the engine rpm can be set lower than the rpm set by the AEC "Stage 2" setting. When normal operations resume, the engine rpm will return to match the Engine Speed Dial 2 setting.
The operational condition of the machine is detected by the implement pressure sensor of the joystick and the travel sensors.
Using the One-Touch Low Idle Feature
The one-touch low idle feature will activate during all "stopped" conditions of the implement, swing, travel, and tools. However, when the "One Touch Low Idle" switch is pressed, the control will lower the engine speed. The speed is reduced to a speed dial setting of 1 or approximately 900 rpm. This control overrides the AEC.
Release of the One-Touch Low Idle
The one-touch low idle switch will be released when any of the following conditions occur:
- The one-touch low idle switch is pressed again.
- Pressure is detected at the implement pressure sensor.
- Pressure is detected at a travel pressure sensor.
- A pressure switch that is related to a tool is set to the ON position.
- An increase in pump pressure sensed by the pump pressure sensors.
The engine rpm is different after the switch has been released. The different speed will depend on the conditions of the release.
- The engine rpm matches the engine speed dial setting when the one-touch low idle feature is released by operating an implement or tool.
- The engine rpm is set by the AEC when the one-touch low idle switch is used to release the one-touch low idle function. The engine rpm will be affected by the following conditions:
- When the AEC "Stage 1" is selected, engine rpm will be set to the AEC "Stage 1" setting. That setting is approximately 100 rpm lower than the current setting of the engine speed dial rpm.
- When the AEC "Stage 2" is selected, engine rpm will be set to the AEC "Stage 1" setting. That setting is approximately 900 rpm.
- Engine rpm matches the rpm of current engine speed dial settings, when engine rpm is lower than the AEC "Stage 2" setting. The setting of this rpm is not based on a setting of the AEC function.
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| Illustration 6 | g06121704 |
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(1) Machine ECM
(2) Monitor (4) Engine ECM (11) Key Switch (12) Hydraulic Lock Solenoid | |
The Delayed Engine Shutdown function allows the engine or exhaust system to run at low idle after the key is turned OFF. This function provides a cool down period for the engine or exhaust system. During the cool down period the engine burns soot that has collected in the exhaust system.
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| Illustration 7 | g02626169 |
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(A) Key OFF position
(B) Emergency Stop position | |
If an immediate stop of the engine is necessary after the key has been turned OFF, turn the key to the Emergency Stop position (full left position).
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| Illustration 8 | g06121705 |
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(1) Machine ECM
(2) Monitor (4) Engine ECM (6) Pump 1 Pressure Sensor (7) Pump 2 Pressure Sensor (8) Implement Pressure Sensor (9) Swing Control Pressure Sensor (10) One Touch Low Idle Switch (11) Key Switch (12) Hydraulic Lock Solenoid | |
The Engine Idle Shutdown function stops the engine automatically when the machine has been idle for longer than the set time. Before the engine stops, a warning message will be displayed on the Messenger.
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| Illustration 9 | g06121143 |
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(1) Machine ECM
(2) Monitor (5) Switch Panel (6) Pump 1 Pressure Sensor (7) Pump 2 Pressure Sensor (13) Left Travel Pressure Sensor (14) Negative Flow Control 1 Pressure Sensor (15) Negative Flow Control 2 Pressure Sensor (16) Power Shift PRV (17) Right Travel Pressure Sensor | |
The pump regulators are controlled by the negative flow control pressure and the power shift PRV. The machine ECM continually monitors various inputs. The machine ECM sends a pulse width modulated (PWM) driver to the power shift solenoid. Power shift solenoid controls the output flow of the pump by changing the hydraulic signal pressure that flows to the pump regulators.
The machine ECM controls the PWM driver sent to the PRV and determines the required pump flow based off the following inputs.
Desired engine speed - Determined by the engine speed dial.
Actual engine speed - Determined by the engine speed pickup.
Negative flow control pressure - Determined by the drive pump pressure sensor and the idler pump pressure sensor.
Drive pump delivery pressure - The drive pump delivery pressure is measured by the drive pump pressure sensor located on the main control valve.
Idler pump delivery pressure - The Idler pump delivery pressure is measured by the idler pump pressure sensor located on the main control valve.
Integrated Engine and Pump Power Management Control
The integrated engine and pump power management control is a suite of software programs loaded into the engine ECM and machine ECM. This power management control performs the function of coordinating hydraulic power demands with engine power production. The machine ECM communicates with the engine ECM to control the flow of fuel to the injectors in coordination with changes in power demands from the various machine systems. The engine output power is matched to the sum of all power loads to ideally provide zero engine speed acceleration or deceleration. The steady-state control output can be attained nearly instantaneously using the CAN Datalink connection between the machine ECM and engine ECM.
The output of the engine will decrease when inferior fuel is used to operate the machine or when the machine is operated at high altitudes. When the engine output decreases, the engine speed will drop during operation.
When the engine speed is decreased by more than 250 rpm below the rpm for a “no load” condition at a given "Engine Speed Dial" setting, the pump flow is decreased in order to reduce the load on the pump.
Boom Down Engine Speed Control
The boom down engine speed limits the speed of the engine when the boom is moving down. This function improves the overall fuel efficiency of the machine. The engine speed is reduced to a value that is less than the setting of the engine speed dial.
The boom lowering operation is detected by the boom lowering pilot pressure sensor and the negative flow control pressure.
When boom lowering is operated only, the engine speed is reduced according to the machine ECM parameters. When boom lowering is operated with other actuators, the engine speed is reduced according to the flow limitation pressure (NFC) sensors.
Automatic Travel Speed Change Function
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| Illustration 10 | g06121138 |
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(1) Machine ECM
(5) Switch Panel (6) Pump 1 Pressure Sensor (18) Travel Speed Solenoid | |
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| Illustration 11 | g02627402 |
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The location of the switch that is used to control the travel speed of the machine. | |
There are two modes of travel for the machine. The modes are "Tortoise" and "Rabbit". The control for the travel speed is located on the touch pad that is located to the right of the operator. The panel includes an indicator in order to display the speed function that is active. When the main pump pressure is low, the travel speed is automatically increased to high speed. When the main pump pressure is high and the selected travel speed is high, the travel speed is automatically switched to low speed. When the travel speed is set to Tortoise, the travel speed is fixed at the low speed (no change).