P&H Mining Equipment says it will continue to add ac drives to its line of electric shovels. In 2004, designs started for an ac drive system for the 4100C Boss, an oil-sand mining shovel; two years later, such a machine has been placed into service in Canada. The company is now expanding its ac models to include the flagship 4100XPC.
The transition from dc to ac will take some time to be applied across the P&H range; however, dc will still be available on all models.
While dc motors have historically been the workhorses of the electric motor arena, recent advances in ac design have yielded advantages in cost, precision control, and reliability in low-maintenance and damp conditions.
Also, ac systems are being added to the well-tested Centurion platform, which uses planetary propulsion and swing systems. While known for dc drive shovels, P&H decided to incorporate its CATIA, Nastran, and FEA findings when developing ac drives for new offerings.
The two ac models are available with P&H Payload or Payload Plus systems that measure dipper payload weight in an effort to maximize productivity by not overloading or short-loading trucks. The Optidig II system prevents stalling and increases the dipper fill, while ShoveLink connects to remote computers to analyze the machine information.The 4100C Boss model has a nominal load capacity of 100 ton (90 t) and a dipper capacity range of 40 to 80 yd³ (30 to 60 m³), while the range-topping 4100XPB has a capacity of 115 ton (104 t) and 47 to 100 yd³ (36 to 76 m³).