The latest electric mining excavators developed by Liebherr are not just converted diesel machines.
The mining excavators and their electric power system were designed and produced entirely by Liebherr. Designed for mine and quarry extraction, the R 976-E electric crawler excavator, and the R 980 SME-E, replaces the ER 974 B.
Built to withstand extreme conditions, they weigh 90 and 100 tonnes respectively and are available in backhoe and shovel versions.
Both excavators are based upon tried and tested electric system, established throughout more than four decades of Liebherr development.
The electric system in the new Liebherr R 976-E 400 kW crawler excavator is supplied with 6,000-volt power via a cable connection, with the cable inlet in the centre of the undercarriage, or on the sides if requested.
A motor cable drum is also available as an option. The machine is powered by a high voltage 6,000 V/50 Hz current collector.
A switch cabinet transformer (high voltage/low voltage) and a low voltage cabinet for power distribution and control of 690 V, 230 V and 24 V networks are located on the upper carriage.
The technology used in the R 976-E and R 980 SME-E mining excavators offers several advantages. Thanks to its constant speed regardless of load, an excavator with an electric engine has a longer service life.
As well, the availability of transient power for complex machine movements enables high productivity. The R 976-E’s low-voltage electric squirrel-cage engine drives the hydraulic system.
The engine features heat shielding on bearings and motor windings. Integrated into a frame with a reinforced flange, it enables safe, soft starting. The two electrical cabinets are assembled by welding into a structure specifically designed to withstand extreme working conditions.
The lockable watertight (IP 65) doors are fitted with safety switches and an emergency stop. The high voltage cabinet is a dedicated contact for power connection and voltage transformer, while the low voltage cabinet is used for power connection monitoring.
In line with its commitment to ecology and sustainability, Liebherr guarantees zero pollutant gas emissions. In addition, to ensure quality, the electric power system was designed and produced entirely by Liebherr-France SAS.
Reduced maintenance and lower operating costs make an electric excavator more cost-effective than a diesel-engine machine. For greater comfort, the R 976-E and R 980 SME-E are extremely quiet. The robustness, reliability and cost-effectiveness of the R 976-E and R 980 SME-E make them products of choice for environmentally friendly extraction applications.
The R 976-E and R 980 SME-E deliver comfort and safety for the operator. The excavators feature a spacious cab equipped with an automatic permanent air-conditioning and heating system, while the exterior has a 270-degree camera system, plus an armoured windscreen and roof window.
The operator’s platform features a large number of additional monitoring functions and a standard large 23 cm screen.