Doosan has added to its Tier IV compliant crawler excavator lineup with the DX420LC-5, DX490LC-5 and DX530LC-5. The new Tier IV compliant excavators replace the interim Tier IV (iT4) DX420LC-3, DX490LC-3 and DX530LC-3.
Doosan DX420LC-5, DX490LC-5 and DX530LC-5 excavators comply with Tier IV emission standards with modified diesel engines and aftertreatment technologies. The engines are optimized for use with a high-pressure common-rail (HPCR) fuel delivery system and a cooled exhaust gas recirculation (CEGR) system. They utilize a diesel oxidation catalyst (DOC) to reduce particulate matter (PM) and selective catalyst reduction (SCR) aftertreatment to reduce nitrogen oxides (NOx). Additionally, the crawler excavators use a variety of aftertreatment systems as part of the Tier IV compliance, such as diesel exhaust fluid (DEF), which is used with SCR technology.
Doosan added a mass airflow sensor and exhaust brake to its existing diesel technologies to help meet Tier IV emission standards. The mass airflow sensor allows the electronic control unit (ECU) to improve the management of airflow from the variable geometry turbocharger (VGT), and to optimize fuel delivery to the combustion chamber based on engine air intake volume and rpm. The VGT is utilized to enhance boost pressure throughout a wide rpm range of the engine, resulting in improved fuel efficiency at lower rpms. This also generates higher torque levels and faster engine response even at low rpm. The exhaust brake helps to maintain consistent engine temperatures at lower engine speeds to improve operating efficiency. Consistent engine temperatures reduce harmful emission levels in the exhaust when the engine is running at lower rpms. Under normal operation, with high rpms, the exhaust brake is inactive. This also generates higher torque levels and faster engine response even at low rpm, and improves machine performance in the Standard and Economy power modes while saving fuel.
An improved 7-in. LCD display panel allows operators to continue monitoring the excavator parameters while viewing the rearview and/or side view camera image. Critical machine data appears next to the camera view. With an optional side camera, a split screen allows both camera displays to be viewed at once. New additions to the monitor include the DEF gauge and improved fuel efficiency.
To help save valuable diesel fuel, Doosan added auto-shutdown to its excavators to help owners save fuel during non-working conditions. Operators can configure the idle time from 3 to 60 minutes. When enabled, the feature will shut down the excavator’s engine when the preset idle time is met. This is particularly helpful in California where state regulations require idling for only 5 minutes for off-highway machines.
New Machine Updates
In addition to auto-shutdown and LCD display panel updates, the new Doosan crawler excavators have the following updates:
• Improved anti-skid plates: increases traction on surfaces
• Auto belt tensioner, fan and air conditioning: simplifies maintenance
• Auto-shutdown: saves fuel during non-working conditions
• Battery upgrades: minimizes downtime
• Emergency engine stop: relocated for easier operator access
• Improved serviceability: allows for easier access to components and less time for maintenance
• LCD panel updates: displays key machine information and camera image simultaneously
• Upgraded alternator: delivers improved power for electrical components
• New front window design: provides good visibility to the work area
Four Power Modes
Similar to previous Doosan excavators, operators can choose from four power modes for more control to better balance fuel consumption and machine power to the working conditions.
Power modes include the following:
• Power+ mode: delivers the fastest workgroup speeds for loading trucks, top digging performance and extra power for digging in hard ground
• Power mode: provides exceptional power and performance for tough digging conditions and truck loading tasks
• Standard power mode: balances the excavator’s fuel consumption in everyday digging, grading and lifting tasks
• Economy mode: reduces fuel consumption for low-demand applications, slows down machine movement for conditions that require extra precision
To further match Doosan excavators to the application at hand, operators can choose from four work modes — digging, breaker, shear and lifting — to maximize efficiency and fuel economy in specific applications. Operators can configure the work mode by adjusting a dial switch on the right-hand console. A work mode icon displays on the monitor after the operator presses the mode button.
A new selectable feature, smart power control (SPC), consists of two systems — variable speed control and pump torque control — that work together to improve machine efficiency while maintaining productivity and reducing fuel consumption. The engine control unit (ECU) automatically manages SPC when SPC is engaged. Each of the four power modes will function with SPC engaged or disengaged; however, SPC can only be active in the digging work mode.
• Variable Speed Control: Reduces engine RPM during low workload requirements such as during the swing portion of a dig cycle. This reduces the total energy required to perform a task and improves fuel efficiency by up to 5 percent.
• Pump Torque Control: Efficiently matches hydraulic pump torque and engine response to the task, preventing engine overload and excess fuel consumption, improving efficiency.
To help improve productivity, an intelligent floating boom is available for Doosan crawler excavators. The excavator’s boom moves or “floats” up or down, without hydraulic flow, allowing the operator to focus on the task at hand increasing efficiency and decreasing the machine workload. In breaker mode, the boom freely moves downward, reducing machine and attachment wear.
Factory-installed options for the new Doosan crawler excavators include the following:
• Straight travel pedal, which allows the operator to travel in a straight line more easily
• Two-way auxiliary hydraulic pedal (in addition to joystick control)
• Diesel-powered coolant heater for cold starts
• Cab guarding for special applications
• Additional work lamps
• Rotate circuit hydraulic piping
Doosan excavators come with a standard three-year subscription to Doosan Telematics, which allows equipment owners and fleet managers to remotely monitor machine location, hours, fuel usage, engine idle versus work time, error codes and engine as well as hydraulic temperatures. Machines can be monitored via an online Doosan Telematics account. In addition, Doosan dealers can provide improved customer support using the system by responding to machine warning messages and alerts, by troubleshooting machine issues, and then sending a field service vehicle to help with repairs and the proper parts.
For more information, visit doosanequipment.com.
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