Overview#
The Generac SD1500 is a 1,500 kW standby (1,350 kW prime) industrial diesel generator set powered by a Mitsubishi S16R-Y2PTAW-1 65.4L V16 engine. Rated at 1,875 kVA standby and 1,688 kVA prime at 60 Hz, it is EPA Tier 2 certified for stationary emergency applications. The genset features the InteliGen NT controller with Proact2 isochronous governing and plus or minus 0.25% steady-state frequency regulation.
Engine and alternator#
The Mitsubishi S16R-Y2PTAW-1 is a 4-cycle, 65.4-liter (3,989 cubic inch) V16 diesel engine delivering 2,346 hp at 1,800 RPM. Key specifications include a 14.5:1 compression ratio, 6.69-inch bore, 7.09-inch stroke, 4-valve cylinder heads, aluminum pistons, and a drop-forged steel crankshaft. The lubrication system uses a gear-driven oil pump with cartridge filtration and a 212-quart (200L) crankcase capacity.
The standard alternator is the Generac K1500064N22, a 4-pole rotating-field design with Class H insulation on both rotor and stator. It features permanent magnet excitation, analog voltage regulation with plus or minus 0.5% steady-state accuracy, and total harmonic distortion below 5%. Motor starting capability is 4,500 skVA at 30% voltage dip on 120/240V.
Power ratings and fuel consumption#
At 277/480V three-phase and 0.8 power factor, the SD1500 delivers 1,500 kW standby (2,255 amps). It is also available at 346/600V (1,804 A).
Fuel consumption at standby ratings: 133.0 gph at 100% load, 97.3 gph at 75%, 66.0 gph at 50%, and 36.5 gph at 25% load. Total fuel pump flow (combustion plus return) is 148 gph (560 Lph).
Physical dimensions#
The open set measures 231 x 107 x 117 inches, weighing 35,078 lbs (15,911 kg). With a 12-hour integral base tank (1,525 gallons usable), dimensions extend to 265 x 125 x 140 inches at 41,778 lbs. The 24-hour tank option (3,050 gallons) extends to 265 x 125 x 156 inches at 44,178 lbs.
Cooling system#
The SD1500 has separate jacket water and aftercooler cooling circuits. Jacket water coolant flow is 489 gpm (1,851 Lpm) with a 100-gallon (389L) capacity. The aftercooler circuit flows 243 gpm (920 Lpm) with a 58-gallon (220L) capacity. Heat rejection to coolant is 2,122,320 BTU/hr (622 kW) for both circuits. The unit-mounted radiator uses a pusher fan (81-inch diameter) at 710 RPM, drawing 83,500 scfm at both 40 and 50-degree C cooling packages.
Our service experience#
The Mitsubishi S16R is the workhorse of the megawatt-class diesel generator market. At 1,500 kW the engine operates at 259 psi BMEP, which is conservative for the 65.4L displacement and contributes to long engine life. The 16-cylinder configuration requires methodical maintenance planning, particularly for injector service which should be staggered across bank A and bank B. The 212-quart oil capacity means oil changes are substantial operations requiring proper containment planning.



