100% Caterpillar
Designed 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 Serviceability
The 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 Confidence
The 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 Heat
The 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 Propel
The 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 Retard
During 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 Alternator
No 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.
Inverter
Cat 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 Motors
The 794 AC uses two 3-phase AC induction traction motors. The high voltage, low current motor is mounted inside the rear axle housing.
Radial Grid
The 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 Blower
The 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.
Additional Features
- 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.