New electronic power optimizing system (EPOS) provides selectable power and work modes for the DX225LC-3 and DX255LC-3 excavators, enabling the customization of power delivery to task.
With operating weights of 49,600 and 56,700 pounds, respectively, the new mid-size Doosan DX225LC-3 and DX255LC-3 excavators feature significant design enhancements, including Tier 4 Interim engines with cooling-system improvements, selectable power and work modes, new cab-mounting system, and an optional floating boom.
Both new models are powered by the Doosan DL06K diesel engine, rated at 167 horsepower for the DX225LC-3 and 185 for the DX255LC-3. The new Tier 4 Interim engine uses an electronically controlled, high-pressure, common-rail fuel system and a variable-geometry turbocharger in conjunction with a cooled-exhaust-gas-recirculation system, diesel oxidation catalyst, and diesel particulate filter. A new electronic fan clutch is designed to improve cooling-system efficiency, while reducing fuel consumption and sound levels.
Doosan’s Electronic Power-Optimizing System (EPOS) is designed, says the company, to provide optimum power and fuel efficiency through a combination of features, including an auto-idle system, machine diagnostics, four work modes—digging, breaker, shear and lifting, plus four power modes—Power +, Power, Standard, and Economy. The selectable work and power modes, says Doosan, allows the operator to tailor machine performance and fuel economy to the task at hand.
Two of the work-mode selections recalibrate machine power for digging or lifting, says the company, and two change auxiliary hydraulic flow for specific types of attachments. Settings are changed via the LCD display panel. The Breaker mode (one-way auxiliary hydraulic flow) is designed for attachments requiring hydraulic power from one direction only, such as breakers or plate compactors, and is designed to maintain consistent down- pressure on the attachment. The Shear mode (two-way auxiliary hydraulic flow) is used with bi-directional-flow, attachments, such as hydraulic clamps, tilting bucket or shear.
A new optional feature for the DX225LC-3 and DX255LC-3 is Doosan’s “Intelligent Floating Boom,” which allows the boom to move freely with the contours of the ground. The new feature is ideal for finishing work, says Doosan, allowing operators to focus on the arm and bucket. When engaged, the boom-float system does not use hydraulic flow, says the company, resulting in added fuel savings and improved cycle times. Another optional new feature is the straight-travel system, using a single foot pedal to control movement of both tracks.
Enhancements for the operator’s environment include a modified ROPS, added seat adjustments, and a new cab-mounting system that uses a dampening plate and internal coil springs, which, says Doosan, reduce vibration by 20 percent. The cab features telescoping-joystick operating levers with integral auxiliary controls, multi-function color LCD monitor, and high-capacity heating and cooling vents.
The DX255LC-5 excavator complies with Tier 4-Final standards with 184-horsepower engine that uses CEGR, DOC and SCR with DEF.
Models DA30-5 and DA40-5 fit in the 28- and 40-metric-ton class, with payload ratings of 61,729 and 88,185 pounds, respectively.