Overview#
The Generac SD750 is a 750 kW standby (675 kW prime) industrial diesel generator set powered by a Perkins 18.1L turbocharged and intercooled inline-6 engine. Rated at 938 kVA standby and 844 kVA prime at 60 Hz, it is EPA certified for stationary emergency applications. The genset features the Generac Power Zone Pro Sync controller with a 7-inch color touchscreen and electronic governing with plus or minus 0.25% steady-state frequency regulation.
Engine and alternator#
The Perkins 18.1L inline-6 (543 cubic inches) delivers 1,112 hp at the rated 750 kW standby output at 1,800 RPM. Key engine specifications include a 14.0:1 compression ratio, 5.71-inch bore, 7.20-inch stroke, and EUI (Electronic Unit Injector) fuel injection. The engine has 7 main bearings, cast iron cylinder heads, and aluminum pistons. The lubrication system uses a gear-driven oil pump with full-flow spin-on cartridge filtration and a 71.8-quart (68L) crankcase capacity.
The standard alternator is the Generac K0820124Y22, a 4-pole revolving-field design with Class H insulation on both rotor and stator. It features permanent magnet excitation, digital voltage regulation with plus or minus 0.25% steady-state accuracy, and total harmonic distortion below 5%. Motor starting capability is 2,100 skVA at 30% voltage dip on 277/480V.
Power ratings and fuel consumption#
At 277/480V three-phase and 0.8 power factor, the SD750 delivers 750 kW standby (1,129 amps). The unit is also rated at 120/208V (2,605 A), 120/240V (2,258 A), and 346/600V (903 A).
Fuel consumption at standby ratings: 49.7 gph at 100% load, 38.0 gph at 75%, 25.6 gph at 50%, and 14.3 gph at 25% load. Total fuel pump flow (combustion plus return) is 111 gph (420 Lph). The fuel system uses 10-micron primary and 2-micron secondary filtration.
Physical dimensions#
The open set without tank measures 154.4 x 71.0 x 74.5 inches (3,923 x 1,803 x 1,893 mm), weighing 10,468 to 10,913 lbs. With a 40-hour integral base tank (2,002 gallons usable), the footprint extends to 290.0 x 71.0 x 110.5 inches. Level 2 sound attenuated enclosures are available up to 207.4 x 71.0 x 150.1 inches.
Cooling system#
The cooling system operates at an engine-rated maximum ambient temperature of 122 degrees F (50 degrees C) before derate. Coolant flow is 128 gpm (485 Lpm) with a system capacity of 27.3 gallons (103.3L). The open set fan delivers 27,376 scfm across the radiator.
Our service experience#
The SD750 shares the Perkins 18.1L platform with the SD600, uprated to 750 kW. At this higher output the engine operates at 443 psi BMEP, making adherence to the maintenance schedule critical. We recommend fuel polishing for low-runtime standby installations and coolant analysis at every oil change to catch early signs of liner pitting.
