Komatsu’s newest small-size excavator is built for versatility in tight spaces

By Jenny LescohierSeptember 13, 2021

A viscous fan clutch adjusts RPM as needed, saving power which can be transferred to the pumps, where it can increase productivity

Komatsu’s new tight-tail PC78US-11 small excavator is now available in the US, offering a compact and easy-to-transport machine that can switch attachments on the fly with lower operating costs than previous models.

Designed for work on roadways, bridges, urban areas, or anywhere space is limited, the 17,700-lb, 68 -hp PC78US-11 joins Komatsu’s family of six small, utility-size excavators.

Replacing the PC78US-10 model, it comes standard with high-flow auxiliary hydraulics and five selectable working modes that offer versatility with precise attachment control.

“This machine is factory equipped with the auxiliary lines already at the end of the stick. You just hook up the work tool, plug the lines in and go to work,” explained Jonathan Tolomeo, Komatsu product manager. “Inside, on the monitor panel itself, you can select from five one-way and five two-way auxiliary hydraulic work tool settings, pick your pressure and setting and name your tool. It’s very easily selectable from the cab, and very easy to use for the operator.”

Fuel efficient, low-cost power

The new Komatsu designed and developed high-efficiency power package and new viscous fan clutch on the PC78US-11 work to lower overall fuel consumption by up to 13%.

“Depending on the temperature of the engine, the viscous fan clutch adjusts RPM as needed, unlike a direct-drive fan which is always turning at max RPM, like in an older car, using power unnecessarily. The power that’s saved there can now go to the pumps, where it can further increase productivity.”

Meanwhile, a simplified catalytic system removes soot without a diesel particulate filter, which in turn can help lower maintenance costs and total cost of ownership.

Centralized service points for simpler maintenance

Large service access doors and grouped service points with ground-level access decrease periodic maintenance labor times and increase overall maintenance efficiencies.

“All the filters are in one area behind one door, so it’s easier for the technician to drain the oil and change all the filters instead of jumping all over the machine to change filters in different locations. That’s a big improvement for this particular model.”

Tolomeo added the PC78US-11 also has an enclosed cooling system. “It’s much more efficient because it’s sealed, it’s a closed cooling circuit,” he said, noting it’s maintenance free until the next scheduled coolant change and also lowers operation and maintenance costs.

Faster cycle times and custom modes to get more done

The PC78US-11 is designed for faster boom up/swing speed, combined with responsive quick arm speed, to make excavating and leveling work easier and more efficient. Six working modes allow operators to tailor the machine to the required tasks, whether for fuel savings or performance.

“Operators will notice the increased speed, but they will really feel the difference in power,” Tolomeo said, “and this translates into greater productivity; getting their job done faster.”

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