Stationary Generator | 400kW | Diesel | 12.5L


*L2 sound attenuated enclosure

Industrial Generator, 400kW | Diesel | 12.5L

Built Strong. Proven Reliable.
Generac’s 12.5 L 400 kW diesel generator delivers dependable standby and prime power performance across industrial, commercial, and municipal applications. Designed for durability and engineered for compliance, it meets UL, NFPA, NEC, ISO, and NEMA standards—providing the strength, efficiency, and scalability that today’s facilities demand.

Features & Benefits

Proven 12.5 L Perkins Engine: Turbocharged and aftercooled inline 6-cylinder engine delivers exceptional efficiency, load response, and long-term durability.
 
POWERZONE® Pro Sync Controller: Advanced 7-inch color touchscreen controller with Modbus® RTU/TCP, Ethernet, and BMS integration—providing comprehensive monitoring, diagnostics, and control.
 
Generator Paralleling Capability: Integrated Modular Power System (MPS) technology enables flexible, cost-effective scalability with up to 99.999% reliability across multiple units.
 
Industrial-Grade Alternator: Brushless permanent-magnet excitation alternator with Class H insulation and <5% THD ensures clean, stable power for sensitive systems.
 
Engineered Enclosures: Generac-built steel and aluminum enclosures offer corrosion resistance, advanced sound attenuation, and all-weather protection with modular service access.

Performance

Cooling System: Closed-Loop Pressurized with 50/50 Ethylene Glycol for reliability in all climates and reduced maintenance.
 
Fuel Type: Ultra-Low Sulfur Diesel (ASTM Specification) for a cleaner operation, regulatory compliance and equipment protection.
 
Sound Levels/Enclosures: Open and weather-protected enclosures with sound attenuation up to 75dBa at 23’ for stringent noise requirements.
 
Construction: Steel or aluminum with RhinoCoat™ powder-coated finish protects against rust, UV and weather for long-term durability

Product Snapshot

Ideal For: Manufacturing plants, data centers, healthcare facilities, and large commercial buildings requiring reliable backup power.
 
Applications: Standby and demand-response systems where reliability, safety, and long-term value are critical.
 
Available Enclosures: Open | Level 0 | Level 1 | Level 2 Sound Attenuated
 
Footprint: Open Unit Dims: 138 x 53 x 68" | SL2 Enclosed Dims: 278 x 58 x 147"
 
Operating Temperature: Up to 122 °F (50 °C) before derate
 
Certifications: EPA Certified Stationary Emergency, UL2200, NFPA 110 Compliant

Specifications

Units:
Fuel Type: Diesel
Engine: Generac
Engine Type: 6-cyl in-line
Engine Size (Liters): 12.5
Engine Output (kW): 400
Running Watts (W): 400,000
kW/kVA Prime: 400/500
Engine Manufacturer: Perkins
Open Set Footprint - L x W x H: inches (millimeters): 137.5 (3,493) x 57.6 (1,463) x 67.8 (1,721)
Enclosed Footprint - L x W x H: inches (millimeters): 180.6 (4,588) x 53 (1,346) x 106.1 (2,696)
Controller Type: Power Zone Pro Sync
Weight (kg): 3,006
Weight (lb): 6,628
Enclosure: Steel or Aluminum
Steel (kg): 1,177
Steel (lb): 2,594
Aluminum (kg): 549
Aluminum (lb): 1,210
HZ: 60
Emissions Compliance: EPA Certified Emergency