Overview#
The Generac SD300 is a 300-kilowatt diesel standby generator powered by an Iveco/FPT 10.3-liter turbocharged and aftercooled inline-six engine. Rated at 300 kW standby and 270 kW prime, it serves the upper-mid range of Generac's SD Series industrial diesel lineup, targeting commercial, healthcare, and industrial applications that demand reliable backup power.
The SD300 pairs the 10.3L Iveco with Generac's Model 520 alternator featuring Class H insulation, permanent magnet excitation, and sealed bearings. The Digital H control panel provides full system monitoring with NFPA 110 Level I and II programmability, Modbus protocol, RS-232/485 communications, and a predictive maintenance algorithm. At 300 kW, the SD300 competes directly with Caterpillar's C9.3, Cummins C300D6, and Kohler 300REOZK.
The 10.3L Iveco/FPT platform#
Moving up from the 8.7L in the SD200, the SD300's 10.3-liter engine uses a 125 mm bore and 140 mm stroke, producing 480 horsepower at rated kW. Piston speed is 1,654 ft/min with BMEP of 336 psi. The higher BMEP compared to the SD100 (165 psi) reflects the engine operating closer to its mechanical limits at standby rating. The genset footprint grows modestly from 128 x 54 to 136 x 58 inches, and weight increases to 5,816 lbs from 4,465 lbs on the SD200.
Heat rejection to coolant is substantial at 814,783 BTU/hr, requiring 14,505 CFM of radiator inlet air. The exhaust exits at 1,020 degrees F at 2,240 CFM -- sizing exhaust ductwork and ventilation for this unit is critical to a successful installation.
Our service experience#
The 300 kW class is a common specification for mid-size commercial buildings, multi-tenant properties, and healthcare facilities in Northern California. The SD300's 10.3L Iveco platform has proven reliable in our service territory. At 22.1 gph full load, fuel planning is important -- a 438-gallon sub-base tank provides approximately 20 hours of runtime at full load. We recommend monitoring coolant system condition closely, as the higher thermal load on the 10.3L makes coolant degradation and hose failures a more common service issue than on the smaller SD models. Exercise the unit weekly and load bank test annually to verify full-load capability.
