Caterpillar has updated the AC electric drive system for Cat® 7495 and 7495 HF electric rope shovels to, it says, deliver even greater reliability, improved maintenance access, enhanced safety and expanded ability to perform at high altitudes and in extreme temperatures.

The updated system also is designed to easily integrate with advanced technologies.

“Caterpillar and our predecessor in shovel design and manufacturing, Bucyrus, have supplied more than 300 AC electric rope shovels,” said Dale Blyth, Product Manager, Electric Rope Shovels. “The most recent advances in AC drives are integrated in this update and demonstrate how we apply our experience to help customers lower cost per tonne and bolster safety.”

Updates include a liquid-cooled motion regulator cabinet for more efficient dissipation of heat generated by electrical components.

The company said: “The new system enables shovels to operate at temperatures of -40 degrees C/F to +50 degrees C (122 degrees F) and altitudes of 5,250 m (17,220 ft) without derating.

“The reliable system also eliminates airborne contaminants in the cabinet and lengthens service intervals – for reduced costs and greater uptime. Additionally, a new, faster propel transferswitch cuts lag time by 75% for improved productivity.” 

New technologies enable consolidating two cabinets in the machinery house to create space for easier maintenance access, while the updated maintenance station is designed for integration of current and future technology solutions, including Cat MineStar™.

The drive system design uses common motors in multiple applications, according to Cat. “That means fewer parts to stock, improved parts availability and simplified maintenance.” 

The new motors also have higher power densities, smaller frame sizes and optimised footprint, which aids access, it added.

The Cat rope shovel electric drive system still features elements such as fuseless insulated-gate bipolar transistor modules. And, the on-board maintenance station continues to aid technicians in identifying faults and resolving issues.

The new electric drive system will be on all new production 7495 and 7495 HF shovels beginning in late 2020.

The system is not intended for retrofit, though some elements, such as the fast propel transfer switch, are available as upgrades to machines already in service, according to Cat.