As the issue of truck idling has taken on greater importance, there has been no shortage of players entering the market with new technologies. Some of the most significant growth has come in auxiliary power units (APU), which are essentially small generator sets, often packaged with heating and cooling units, mounted to a truck.
A new player in the market is Black Rock Systems LLC, Reno, Nev. The company was founded to develop APU technology for heavy-duty trucks. But what's a little different about the company's approach with its debut product is that it's more than a single APU. Instead, the Blackrock APU is available with two generator outputs ranging from 3.7 or 6 kW, driven by two- or three-cylinder Yanmar liquid-cooled diesel engines.
"For probably about 75% of the market, the two-cylinder is more than ample," said Steve Rovarino, vice president, sales and marketing at Black Rock Systems LLC. "It gives them all of the power they need. But for someone like a deluxe owner-operator who's in Arizona, he's better off with the three cylinder.
"For extreme operating environments or situations where there is more of a load than you'd usually see, the three-cylinder is really the answer."
The Blackrock APU was in development for approximately a year and a half and debuted at the Mid-America Trucking Show earlier this year. Both models are powered by Yanmar TNV diesel engines--the two-cylinder, 2TNV70 and the three-cylinder 3TNV70. The liquid-cooled engines share the same bore and stroke dimension (70 x 74 mm) and have standard ratings of 11.6 and 17.4 hp respectively at 2800 rpm. Both meet EPA Tier 2 and EU Stage 2 engine emissions standards, the company said.
Engine air filtration is through a Donaldson air cleaner and cooling is provided by an SRF America radiator with twin Spaal fans, which are matched to eliminate APU overheating even in the harshest conditions, according to the company. Rovarino said Black Rock "looked at the option of interfacing with the main truck systems," but ultimately decided that the more prudent course would be to make the APU completely self-contained. "If there would ever be a problem with the APU, you wouldn't want to have it take down the whole truck," he said. "That's why we felt that it was better to keep the systems separate. There are also sometimes warranty issues if you get into the truck engine's main systems."
The engines drive Sincro brushless generators and a 12 Vdc alternator through a belt drive system. Along with the 120 V of ac power, the system also operates a combined HVAC unit that is packaged separately. The unit can provide 26,000 Btu/hr of heating and cooling, the company said. In addition, the APU can also supply power to an engine block heater to provide easier starting in cold climates. The system is controlled through Black Rock's Smart Power Management system that is designed to provide load balancing between electrical and climate systems. Instrumentation provides indication for conditions such as low oil pressure, high coolant temperature, engine overspeed and underspeed and generator or alternator problems.
Typical fuel consumption at load for the two-cylinder unit is 0.2 gph and 0.3 gph for the three-cylinder, the company said.
The APU is packaged for mounting on the frame rails, with the location dependent on the truck configuration and customer preference. Frequently, it is mounted behind the cab or it can replace the step assembly leading into the cab. Dimensions for the APU are 29.5 in. wide, 28.5 in. high and 30 in. deep. Weight ranges from 425 lb. for the two-cylinder unit to 480 lb. for the three-cylinder set. The HVAC unit is 17 in. wide, 10 in. high and 18 in. deep and with the HVAC system, the total weight of the unit ranges between 455 and 510 lb.