Caltrans Not Shaken By July 6 Earthquake Damage

Cat 990H Wheel Loader Features Low-Emissions Engine

Thu April 05, 2007 - National Edition
CEG



The Caterpillar 990H wheel loader incorporates innovations to lower engine emissions, improve reliability, durability and serviceability, and optimize operator efficiency and comfort, according to the manufacturer.

The 990H replaces the 990G Series II and retains the productive cycle times, pass matches with standard sized haulers, impeller clutch torque converter and Rimpull Control System for increased operator control and optimum power to the ground, and STIC control system for reduced operator effort.

The 990H is engineered for mining, bulk materials handling and high volume earthmoving. The machine loads 60-to 70-ton (54 to 63-t) capacity trucks in the standard lift arrangement and 100-ton (91 t) capacity trucks in the high lift arrangement.

Rated payload in the standard lift arrangement is 16.5 tons (15 t) and operating weight is 171,642 lbs. (77,842 kg). Bucket capacities range from 11 to 12 cu. yds. (8.4 to 9.2 cu m).

New Engine Meets EPA,

EU Regulations

The Cat C27 engine, rated at 627 net hp (468 kW) features ACERT Technology. The 12-cylinder engine is a V configuration with displacement of 1,648 cu. in. (27 L).

Key elements of ACERT Technology include:

• A mechanically actuated, electronically controlled unit injection system that delivers micro-bursts of fuel to the combustion chamber just prior to and after the main injection for reduced emissions.

• A 32-bit ADEM IV control system that manages the fuel injection process and other power train operations with precision and accuracy, reducing emissions, while boosting performance and maximizing component life.

• A cross-flow cylinder head that brings more clean air into the combustion chamber and improves its distribution, ensuring a cleaner combustion process.

This combination of technologies makes the new Cat C27 engine clean, quiet, fuel efficient and compliant with U.S. Environmental Protection Agency Tier III standards and EU Stage IlIa standards. The C27 also offers 500-hour oil change intervals for reduced maintenance costs. Also, fewer mechanical parts boost reliability.

The 990H also features an air-to-air aftercooling (ATAAC) system to reduce the temperature of air feeding the engine intake. The cooled, compressed air reduces engine emissions and helps maintain performance at high altitudes and in high ambient temperatures.

The 990H power train also features the impeller clutch torque converter (ICTC). The system allows the operator to modulate rimpull efficiently using the left pedal for smooth loading cycles.

In addition, the Rimpull Control System allows the operator to vary rimpull to match underfoot conditions by selecting one of four preset, reduced rimpull settings. The system optimizes productivity while reducing tire slippage, tire wear and costs.

Cooling System Efficient,

Easier to Service

The next generation modular radiator (NGMR) improves serviceability and increases cooling efficiency by 22 percent, according to the manufacturer.

NGMR routes coolant through the radiator twice for better cooling. Also, the modular core allows removal of a single module without removing the entire radiator. The result is reduced downtime and lower repair costs.

The cooling system design isolates the NGMR and the hydraulically driven, variable-speed cooling fan from the engine compartment, which allows the radiator to receive ambient air from outside rather than receiving heated air from the engine compartment. The design increases heat exchange while minimizing the size of the radiator.

The radiator size allows the hood to be sloped for enhanced sight lines to the rear of the loader. Also, the efficient radiator allows the fan to run at lower speeds, which reduces sound levels, power demand and fuel consumption.

Comfortable Operator

Station

The cab is spacious and provides increased visibility to the work area. Interior sound levels are below 75 dB(A). The comfort series seat has an air suspension and is adjustable to fit the operator. A trainer seat promotes proper operational and safety training.

The 990H retains the steering and transmission integrated control (STIC) system that enables the operator to use small movements of a single hand to steer and to make direction and gear changes. STIC enables smooth operation with minimum effort.

The electronic monitoring system III (EMS III) continually monitors machine systems and provides a three-level warning system to alert the operator of problems. EMS III stores and shares information with machine systems so that it can be used by a technician to simplify diagnostics and service.