Plant Equipment and Hire March 2018 | Page 49

PRODUCT FOCUS To make the EX2 prototype fully electric, the combustion engine has been replaced with two lithium ion batteries, totalling 38kWh, which store enough electric energy to operate the machine for eight hours in an intense application, such as digging compact ground. The hydraulic architecture has also been replaced with electric architecture, which incorporates electromechanical linear actuators that help to optimise the transmission chain. Removing the hydraulic system and the combustion engine, as well as reducing the cooling needs, has led to significantly lower noise levels, while decoupling the subsystems, as well as using highly efficient actuators and power sources, increases total machine efficiency and controllability. “The electrification of construction equipment will produce cleaner, quieter, and more efficient machines — this represents the future of our industry,” says Ahcène Nedjimi, electrics and electronics systems lead engineer and EX2 project leader. The EX2 is a revolutionary machine. With its zero emissions and 10 times lower noise levels, it could easily be used in densely populated areas without disturbing people — even at night. Ten times higher machine efficiency and maintenance-free systems mean that operating costs and total cost of ownership would be significantly reduced. “Because the EX2 is fully electrified and there are no mechanical joysticks, it can be controlled remotely from a mobile phone or tablet,” Nedjimi continues. “This increases safety in hazardous working environments. Additionally, the EX2 delivers the same power and force as its conventional counterpart, as well as faster speeds in combined movements. As this type of movement is the most common kind for this machine, productivity is improved. All of this has been achieved without compromising on machine performance, ensuring customer needs would be fulfilled.” The EX2’s efficiency means that average power consumption is comparable to that of a large iron (3.5kW), significantly reducing operating costs and total cost of ownership. The machine also does not require any power when in idle mode, which adds to the significant reduction in operating costs since this type of compact excavator usually spends approximately 40% of its time in idle mode on a job site. The lack of engine or hydraulics reduces maintenance requirements, while the lower cost of electricity compared to diesel means that fuelling a fully electric machine will reduce operating costs. The EX2 can also recover energy; its fully reversible system means that energy is recovered when the boom is lowered and the cab is rotated. The EX2 has been designed to work in four different ways. It can be fitted with two 600V, 19kWh lithium ion batteries, which last a minimum of four hours each (a total of eight hours) if the machine is continuously digging (trenching cycles, which are not the main operation for this type of machine — they are usually only operated for around three