Overview#
The Blue Star MD800-01 is an 800-kilowatt Tier 2 diesel standby generator built around a Mitsubishi S12A2-Y2PTAW-2 engine — a 33.9-liter, 12-cylinder V-configuration turbocharged and water/air-intercooled diesel producing 1,207 HP at 1800 RPM. It is the entry point of Blue Star's Mitsubishi MD product line, a series that extends from 800 kWe to 2,000 kWe and covers the upper boundary of industrial standby power.
Blue Star Power Systems (North Mankato, Minnesota; DEUTZ AG subsidiary since 2024) assembles the MD800-01 on a structural steel base with a Stamford S6L1D alternator (voltage-dependent model) and DSE DCP7310 controller. It is a three-phase-only unit available at 208V, 240V, 480V, 600V, and 4160V. The 4160V option — rare below this power class — uses a Stamford MVWI734E medium-voltage alternator and is particularly relevant for large industrial facilities and utility-scale applications that distribute power at medium voltage.
The Mitsubishi S12A2 platform#
The S12A2 is Mitsubishi's smallest generator-duty V12, distinguished from the larger S12H and S12R by its shorter stroke (6.30 in vs 6.89 in for the S12H). At 33.9 liters, it delivers 1,207 HP at standby rating with a 15.3:1 compression ratio and water-to-air intercooling, a more complex cooling system than the John Deere PowerTech engines used in Blue Star's smaller models. The intercooler runs on a separate coolant circuit, which adds a second fluid system to track at service intervals.
The altitude deration ceiling — 3,280 ft (1,000 m) at 104°F (40°C) — is consistent across the entire MD product line and meaningfully better than the 1,677 ft ceiling of the 6090-series JD models.
When to spec the MD800-01#
- 650–800 kW continuous emergency loads on three-phase power
- Sites requiring medium-voltage (4160V) output without a step-up transformer
- Industrial facilities, large campus distribution, and municipal critical infrastructure at this power level
- Projects where the John Deere JD300-02 is insufficient and a megawatt-class unit is more than required
Our service experience#
At 18,750 lbs OPU, the MD800-01 requires a purpose-engineered structural pad. The two 9,000W 240V jacket water heaters (installed in parallel with isolation valves) reflect the engine's large coolant mass. Fuel at full load (64.3 gph) means a 500-gallon tank provides approximately 7.8 hours of runtime — fuel logistics planning is important for extended outages at this power level. Mitsubishi S12A2 parts are available through industrial engine suppliers, though not as universally as John Deere 4045 or 6090 parts.
