Power Train - Cat AC Electric Drive
Gives you more power to the ground for greater productivity.
100% CaterpillarDesigned and manufactured by Caterpillar, the MT4400D AC is a 221 tonne (244 ton) AC electric drive truck that is single sourced from Caterpillar and supported through the Cat dealer network. The MT4400D power train works seamlessly with the 3516C HD engine to create a smooth ride and offers exceptional safety, serviceability and performance.
Modular Design for Excellent ServiceabilityThe modular design allows for easy removal and installation of components. The engine, traction alternator/generator, motors, inverter, grid, and final drives can be removed independently. The close coupled, dual bearing, traction alternator allows for easy mounting to the 3516C HD engine.
Superior Control Yields Excellent Operator ConfidenceThe Cat AC drive system gives you the best retarding, braking, and control in the industry. Class leading dynamic retarding coupled with blended braking, of the rear wet disc brakes and the front dry brakes, provide the operator with exceptional control and confidence.
High Voltage - Lower HeatThe Cat AC drive is a high voltage system (2,600 volts) that operates at relatively low current. The result is lower heat generation, smaller/lighter components, and longer component life.
The Cat AC Electric Drive in PropelThe 3516C HD diesel engine drives the close coupled traction alternator through an isolation coupler. The AC power is rectified to a nominal 2,600 volts to form the DC link. The DC link supplies power to the Inverter where IGBT’s convert the DC signal to 3-phase AC to drive the traction motors. Motor output drives the wheels through a Caterpillar double reduction ring output final drive.
Cat AC Electric Drive in RetardDuring retarding the wheel motors become generators. Motor power is fed back through the DC link. The power is fed to the contactor and chopper circuits and then exhausted through the radial grid. A brushless AC fan blows air across the grid to dissipate the power and control retarding speed.
Traction AlternatorNo shimming or radial alignment required with the close coupled, dual bearing alternator, resulting in decreased install time. The excitation system is brushless which has longer maintenance intervals than brush type systems.
InverterThe Inverter uses Mitsubishi Electric IGBT Phase Modules to control the rimpull, direction and speed of the truck. Mitsubishi Electric is the leader in IGBT technology.
Traction MotorsEach traction motor is a 3-phase AC induction type. The high voltage, low current motor is mounted inside the rear axle box.
Radial GridThe radial design grid sits well back on the deck giving operators excellent visibility to the right side. The grid features the highest retarding power in the industry, better grid life, and is significantly quieter than box grids. The AC electric motor does not require any maintenance, which is a significant savings to the customer over DC motor systems.
Variable Hydraulic BlowerThe hydraulic drive blower motor offers exceptional cooling, even in extreme environments. The variable hydraulic blower has the ability to provide the required cooling, even while the truck is at idle, compared to direct drive motors that are dependent on engine rpm. The variable blower is better at keeping critical components cool, and thus ensures long component life.
- Anti roll back prevents the machine from moving in a direction opposite the operator’s intent.
- The grid dry function dries the grid quickly in inclement weather.
- Traction Control System (TCS) electronically monitors individual wheel speed and adjusts the torque of each final drive to mitigate the hazard and keep the operator in control.
- Reverse Shift Inhibit ensures reverse propulsion is not applied when the truck is moving forward.
- Cat AC drive system is trolley capable.
Power Train - Engine
Power, reliability and efficiency for your most demanding mining applications.
EngineThe Cat 3516C HD is a quad turbocharged diesel engine that provides maximum performance in the most demanding mining applications.
DesignThe 3516C HD is a 16 cylinder design that uses long effective power strokes for more complete fuel combustion and optimum efficiency. The large 78.1 liter displacement, low rpm, and conservative horsepower ratings mean more time on the haul roads and less time in the shop.
Electronic Control Module (ECM)The ECM utilizes advanced engine management software to monitor, control and protect the engine utilizing self-diagnosing electronic sensors. The computerized system senses operating conditions and power requirements and adjusts the engine for peak performance and the most efficient operation at all times.
Cat Data LinkCat Data Link electronically integrates the engine and machine computer system to optimize overall power train performance, increase reliability, maximize component life, and reduce operating costs.
Cat Electronic TechnicianProvides service technicians with a tool to access stored diagnostic data through the Cat Data Link to simplify problem diagnostics and increase machine availability.
Engine/Power Train Integration
Reduced operating costs through electronically coordinated power train components.
Control Software and Integration
The integrated controls of the MT4400D AC make the truck simple to operate. They provide:
- Excellent slow speed control for safety within the service areas.
- Excellent throttle response on acceleration to move out of the loading or dump areas.
- Dynamic retarding with blended service brakes, at low speed.
Cat Data Link
Caterpillar’s proprietary electronics and controls allow complete machine system integration. The Cat Data Link port provides one location to access all system information for programming function, instead of individual locations for drive system and engine. All computer systems are linked to:
- Optimize power train performance.
- Increase reliability and component life.
- Reduce operating costs.
- Improves fuel efficiency.
Cat Braking System
Excellent braking control gives operator’s confidence.
Industry Leading Dynamic RetardingThe radial grid is rated at 3.281 MW (4,400 hp) - allowing you excellent control of the truck speed in long retarding applications. The radial design is light, efficient and quiet.
Brake DesignHydraulic brake actuation system features fully modulated service brakes (foot, or hand operated system), fully modulated secondary brake (foot or hand operated), loading brake for use under the shovel and a spring applied/hydraulic release park brake.
Rear Wet Disc BrakesThe wet disc brakes provide the operator with excellent control and confidence in the truck. The Cat oil cooled brakes in the rear wheel assemblies are designed with large discs and plates for reliable and adjustment free operation. They are enclosed and sealed to prevent contamination and provide long life. These oil disc brakes provide exceptional braking at all speeds.
Front BrakesThe four calipers/wheel dry front brakes offer excellent stopping capabilities and are very robust.
Blended BrakingFull electric retarding effort will be maintained down to a truck speed of 3.2 km/h (2.0 mph). Blended braking of the service brakes (60/40 split rear and front service brakes) occurs between 3.6-4.0 km/h (2.25-2.5 mph) and will be used to completely stop the truck and hold it stationary.
Automatic Retarding ControlOperator controlled - (ARC) engages automatically and maintains speed consistently. A simple toggle switch is used to adjust retarding speed.
Anti-RollbackAutomatically applies service brakes to prevent the truck from rolling from a stop opposite the intended direction of travel.
Reverse Shift InhibitEnsures reverse propulsion is not applied when the machine is moving forward.
Park Brake AlarmPark brake alarm alerts the operator if he starts to exit the cab before the park brake has been applied. This feature helps prevent accidental machine movement.
Cat structures are known for being the best in the industry for durability and long life.
Straight Rail Frame
The MT4400D AC utilizes a straight rail design. The straight rail design eliminates bends and breaks, which are sources of stress concentrations.
- Box Section Construction - The box section construction utilizes Caterpillar proprietary steel specification, which has very low sulfur content and provides excellent welding characteristics, plus outstanding durability.
- Deep Section Main Rails - Deep section main rails, in critical areas of the frame, lower the stress levels resulting in increased frame life.
- Tubular Center Cross Beam - The tubular center cross beam with hoist cylinder and axle box attachment eliminates torsion and eccentric loads associated with conventional designs. The axle box attachment is integrated into the cross member and the bearing surface is replaceable.
Integrated Four Post ROPS CabDesigned to maximize the operator space by deforming the support structure rather than compromise the operator compartment. The transverse mounting beams absorb energy by deflecting around established pivot points, maintaining the integrity of the operator compartment.
Single Beam Front AxleThe single beam front axle is designed for load sharing on the beam, resulting in flatter turns and sharing of tire loading for better tire life. This lower structure absorbs the road undulations, giving a better ride and decreasing operator fatigue levels.
Nose Cone BearingMT4400D AC has a center cross member that incorporates a wraparound spherical axle box nose cone connection. This nose cone attachment features a patented, large two piece bearing that reduces contact pressure to less than 9653 kPa (1,400 psi) allowing for a longer bearing life. The replaceable bearing surface in the axle box attachment is lubricated, sealed, and integrated into the cross member for easy access and maintenance.
Suspension SystemThe design of the suspension system utilizes Nitrogen/Oil suspension cylinders that feature pin to pin mounting allowing for access and change out of components without having to remove the tires.
Durable DesignDouble shear clevis attachment both top and bottom allows for easy removal and installation of suspension. The Nitrogen/Oil suspension cylinders reduce input loads into the structure for improved fatigue life and better ride.
Truck Body Systems
Caterpillar designed and built for rugged performance and reliability.
Cat BodiesIntegral to the truck, the body is designed to fit with the chassis and work as part of the truck system. Each body is sized to meet the payload requirements without compromise to vehicle balance, braking or control.
Cat Body Choices
Body options include the popular Conventional Body, lightweight High Efficiency Body, and Gateless Coal Body. Liner options fit the body to the application.
- Conventional Body - Based on the mine site evaluation of your mine, the body is sized and configured to meet the specific needs dictated by fragmentation, abrasion, cohesion, and the loading tool. This body achieves an excellent balance of payload and durability (shown in picture).
- High Efficiency (HE) Body - The body is sized and configured to meet the specific needs dictated by fragmentation, abrasion, cohesion, and the loading tool to maximize the payload capability of the truck.
- Gateless Coal Body - Eliminating problematic tail gates - the Gateless Coal Body is intended for dedicated coal haulage.
Keeping your production at peak levels.
VIMS™ 3G Monitoring SystemProvides operator critical health and payload information in real-time to keep the MT4400D AC performing at optimum levels. VIMS is able to monitor information from all vehicle systems. Ten (10) different machine parameters can be viewed at once. Data can be downloaded easily by Service Technicians for troubleshooting, planning and lowering costs.
Advisor DisplayThe Advisor display provides real-time performance, maintenance and diagnostic data to the operator or service technician. A large number of machine parameters can be viewed including temperature, pressure, speed, and payload.
Payload ManagementInformation is available to manage payloads to improve fleet effectiveness and loading tool match. It can help prevent overloading to extend component life and lower operating and maintenance costs.
External Payload IndicatorsStandard external lights or optional digital display to help loading tool operator reach payload target and minimize overloading.
VIMSpcAn Off-board software reporting program that allows your service personnel to download a complete record of machine health and productivity data. Health and payload reports can be generated for more effective machine management, which reduces downtime and lowers operating costs.
VIMS SupervisorOptional software allows your mine personnel to easily manage and interpret VIMS data for optimum fleet management and productivity.
Ergonomically designed for all-day comfort, control and productivity.
Operator EnvironmentThe Cat MT family cab can accommodate two full size reclining seats, while providing ample storage space behind the seats.
Ergonomic LayoutTo minimize operator fatigue and maximize productivity, the Cat MT family operator station is ergonomically designed for total machine control in a comfortable, productive and safe environment. Controls, levers, switches and gauges are positioned for ease of use.
Viewing AreaDesigned for excellent all-around visibility and clear sight lines to the haul road, the large viewing area offers exceptional visibility, allowing the operator to maneuver with confidence for high productivity. The operator environment was designed with curved front glass to provide a 191-degree view. Support pillars have been moved further back to provide a more unobstructed front view. Deck compartments have been positioned to minimize impact on the side field of view.
The most experienced dealer network in the world.
Commitment to Meet Your NeedsCat dealer 24/7 support offers solutions, services and products to help you lower costs, enhance productivity, and manage your fleet anywhere in the world. Expert technicians have the knowledge, experience, training, parts and tooling to keep your MT4400D AC running at high availability.
Product SupportCaterpillar supports the MT4400D AC with a worldwide network of parts distribution, dealer service centers and technical training facilities. Our global dealer network is ready to meet your support needs around the clock and around the world.
Cat dealers offer a wide range of service plans to help maximize your uptime and return on your investment, including:
- Preventive Maintenance Programs
- Diagnostic Services such as Scheduled Oil Sampling and Technical Analysis
- Rebuild and Remanufactured Product Options
- Customer Support Agreements
Application AwarenessApplication and site-specific factors such as material density, loading practices, payload, speed, grade and haul road design and maintenance influence the cost to operate and maintain your haulage fleet. Your Cat dealer can provide help in understanding the effects application factors and operating practices have on maintenance and operating costs. They also offer training to help operators improve productivity, decrease downtime, reduce operating costs and enhance safety.
Reduced maintenance time results in more productivity.
Modular DesignMajor components can be serviced individually with minimal removal and installation time. Work platforms and step/stairs are located in key service areas. The close coupled, dual bearing, generator/alternator is separate from the engine and can be removed without removing the body - wheel motors are separate from final drives.
Ground Level AccessGrouped service points (4 filter service groups) allow convenient access to tank levels, filters, drains and S·O·SSM oil sampling ports.
- Open engine access with service platforms makes maintenance easy. Traction alternator and inverter platforms allow for easier inspections, troubleshooting, and component change outs.
- Hydraulic cabinet shows critical pressures for all key system in one centralized location.
Separate Hydraulic and Electric LinesHydraulic lines run inside the left side of the frame, while the electric lines run inside the right side of the frame. This makes servicing and replacement quick and easy.
Designed with safety as the first priority.
Product Safety is a CommitmentCaterpillar is concerned about your safety. We continue to be the industry leader in proactive development of machines and features that exceed safety standards.
ControlsThe Cat drive control features anti roll back, traction controls, a park brake warning when exiting the cab, and an automatic retarder that inspires operator confidence.
IsolationThe MT4400D AC features a ground level system lockout, VIMS monitoring, and stored energy dissipation at shutdown. These features, and the excellent serviceability of the MT4400D AC, allow your technicians to perform repairs safely and quickly.
Access/EgressStandard 600 mm (24") wide ladders, flat deck, toe kicks, and optional power access stair attachment allows for easy and safe access and egress.
Reduced maintenance time results in more productivity.
Sustainability FeaturesThe MT4400D AC Mining Truck offers continuous rear axle filtration and extended maintenance intervals which aid in decreasing the amount of waste contributed to our environment.
Remanufacturing OptionsCat MT trucks are designed to be rebuilt and deliver a long life. Many MT4400’s have logged over 100,000 hours of frame life. Components are designed to be remanufactured for multiple service lives.
Engines with Advanced TechnologyCat engines feature advanced technology components that contribute to better fuel economy and decreased emissions.
12,000 Hour Coolant and Low Oil/Lube ConsumptionMT4400D AC has exceptionally low oil and lube consumption when compared to the competition. This provides a reduced impact on the environment, lower cost of ownership, and less maintenance time.