Power Train – Cat AC Electric Drive
Delivers you more power to the ground for greater productivity.
100% CaterpillarDesigned and manufactured by Caterpillar, the 794 AC is a 291 tonnes (320 tons) AC electric drive truck that is single sourced from one manufacturer and supported with the best dealer network in the industry. The 794 AC drive system works seamlessly with the C175-16 engine 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, motors, inverter, grid, and final drives can be removed independently. The close coupled, dual bearing traction alternator allows for easy mounting to the C175-16 engine.
Superior Control Inspires Operator ConfidenceThe Cat AC drive system gives you the best retarding, braking, and control in the industry. Class leading dynamic retarding coupled with blended service braking of the four corner wet disc 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 lower current than the competition. The result is lower heat generation, smaller/lighter components, and longer component life.
The Cat AC Electric Drive in PropelThe C175-16 diesel engine drives the close connected Traction Alternator/Generator 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. Traction motor output drives the wheels through a double reduction ring gear output final drive.
Cat AC Electric Drive in RetardDuring retarding the traction/wheel motors act as generators and 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. An 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.
InverterCat ECMs and software work with the Mitsubishi Electric IGBT Phase Modules to control the rimpull, direction and speed of the truck. Mitsubishi Electric IGBT technology is the proven leader for AC drive systems.
Traction MotorsThe 794 AC uses two 3-phase AC induction traction motors. The high voltage, low current motor is mounted inside the rear axle housing.
Radial GridThe radial design grid sits to the rear of the cab 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 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 ensures long component life.
- The grid dry function dries the grid quickly in inclement weather.
- Traction Control System (TCS) helps operators maintain control in poor underfoot conditions. TCS monitors and adjusts front and rear wheel speeds and independently adjusts them to prevent wheel slip and slide.
- Cat AC Drive system is Trolley capable.
Power Train – Engine
Delivers power, reliability, and efficiency for your most demanding mining applications.
Cat C175-16 EngineThe Cat C175-16 is a quad turbocharged air-to-air after cooled diesel engine that has enhanced power management capabilities for maximum hauling in your most demanding mining applications. The 16-cylinder, four stroke design uses long, effective power strokes for optimum efficiency.
Engine BlockThe C175-16 engine block is comprised of a high tensile strength ferrite ductile cast iron alloy. This design offers increased resistance to stress cracking and offers support to the cylinder liners, allowing for increased head gasket sealing capability.
ServiceabilityThe design of the C175-16 enhances serviceability. The inlet manifolds and turbochargers are located outside of the engine’s V, giving the service technicians more space to work on top of the engine and within the engine bay.
Electronic Control Module (ECM)The ECM utilizes advanced engine management software to monitor, control and protect the engine utilizing self-diagnosing electronic sensors.
Pistons and Connecting RodsA forged steel, one piece piston design has an improved stainless steel top ring set. The top ring reduces ring groove and liner wear and is corrosion resistant.
Cat Common Rail Fuel SystemThe electronically-controlled system senses operating conditions and regulates fuel delivery for optimum fuel efficiency. This precise and flexible fuel system gives the engine the ability to meet emission regulations without sacrificing performance, reliability or durability.
Engine/Power Train Integration
Delivers low operating costs through electronically combined power train components.
Control Software and Integration
The Cat engine, AC drive system, hydraulics and controls have been integrated to make the truck easy to operate and provides:
- Excellent slow speed control for safety within the service areas.
- Superior throttle response on acceleration to move out of the loading or dump areas.
- Dynamic retarding with blended four corner wet disc service brakes, at low speed.
Cat Data Link
Cat Data Link provides one location to access all machine information from all machine sub systems. Unique tools are not required to access the drive system, engine and machine information. All systems on the 794 AC are in constant communication with each other to:
- Optimize power train performance.
- Increase reliability and component life.
- Reduce operating costs.
Cat Braking System
Delivers operator’s confidence, to maximize your productivity.
Industry Leading Dynamic RetardingThe radial grid is rated at 4.086 MW (5,480 hp) – allowing excellent control of the truck speed in long retarding applications. The radial design is light, efficient and quiet.
Brake DesignThe Hydraulic brake actuation system is electrically modulated so that the first 80% of brake pedal travel uses dynamic braking while the remaining 20% uses the wet disc service brakes. The emergency service brake pedal uses full hydraulic modulation of the wet disc brakes. The loading brake is used for under the shovel and applies the rear service brakes.
Four Corner Wet Disc BrakesThe wet disc brakes provide the operator with excellent control and confidence in the truck. The front and rear Cat oil cooled brakes 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.
Dual Functioning Brake Pedal and Blended BrakingThe dual functioning brake pedal gives the operator confidence when going downhill. The first 80% of the pedal activates only the dynamic brakes, but the operator has the ability to blend in the wet disc service brakes, with the remaining 20% of the brake pedal’s range. When the operator is coming to a stop, the service brakes will automatically blend in at low speeds.Full 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, eliminating troublesome dials in competitor trucks.
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, which helps prevent costly damage to the engine and drive system.
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 movement.
Cat structures are known for being the best in the industry for durability and long life.
Straight Rail Frame
The 794 AC utilizes a straight rail design. The straight rail design eliminates bends and breaks, which occur at 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 an increased frame life.
- Tubular Center Cross Beam – The tubular center cross beam with hoist cylinder and axle box attachment provides robust performance. The axle box attachment is integrated into the cross member and the bearing and pin are replaceable.
Integrated 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.
The design of the suspension system utilizes Nitrogen/Oil suspension cylinders that feature pin to pin mounting to allow for access and change out of components without having to remove the tires.
- Durable Design – Double 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
Delivers a true 291 tonnes (320 tons) and provides rugged performance and reliability.
Integrated Body and Chassis DesignIntegral 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.
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.
- Curved floor, front, and canopy strengthens entire body as a structure.
- Strength of base plates allows minimal wear package and low operating weight.
- Joint isolation system reinforces welded areas and exploits high strength main plates.
- Runners transfer weight to the truck frame.
Keeping your production at peak levels.
VIMS™ 3G Monitoring SystemProvides operator critical health and payload information in real-time to keep the 794 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 digit 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 794 AC 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 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. The 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.
- Adjustable Steering Column
- Turn Signals
- Gauge Cluster
- Advisor Display
- 191-degree Viewing
- Right Gauge Panel
- Indicator Light Panel
- Circuit Breakers (under dash)
- Air Suspension Seat
- Automatic Retard Control
- 3-Point Seat Belt (driver) (2-Point companion)
- Storage Compartment
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 794 AC running at high availability.
Product SupportCaterpillar supports the 794 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.
Delivers easy service for more uptime and 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, traction alternator is separate from the engine and can be removed without removing the body – traction/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 optional inverter platforms allow for easier inspections, troubleshooting, and component change outs.
- Hydraulic cabinet shows critical pressures for all key systems in one centralized location.
Sealed Electrical ConnectorsElectrical connectors are sealed to lock out dust and moisture. Harnesses are enclosed in conduit or braided for protection. Wires are color coded for ease of diagnosis and repair.
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/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 controls feature anti-roll back, traction controls, a park brake warning when exiting the cab and an automatic retarder that inspires operator confidence and error prevention.
IsolationThe 794 AC features a ground level system lockout, engine lockout and propulsion lockout (in ECM cabinet), VIMS monitoring, and stored energy dissipation at shutdown. These features, and the excellent serviceability of the 794 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 794 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 Options794 AC trucks are designed to be rebuilt and deliver a long life, many 794 AC trucks have logged over 100,000 hours of frame life. Components are designed to be remanufactured for multiple service lives.
Engines with Advanced TechnologyEngines with advanced technology contribute to better fuel economy and decreased emissions.
12,000 Hour Coolant and Low Oil/Lube Consumption794 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.