Kohler KG400

Overview#

The Kohler KG400 is a 400-kilowatt commercial standby generator — the largest single unit in Kohler's industrial gaseous (KG) lineup. It represents the ceiling of what gaseous technology delivers in a single frame: a turbocharged-aftercooled 21.9L V12 producing serious power on natural gas or propane without a drop of diesel.

Above 400 kW gaseous, the answer is paralleling. Two KG400 units provide 800 kW with full N+1 redundancy; three provide 1.2 MW. This makes the KG400 the building block for large gaseous paralleling arrays at campuses, hospitals, and government facilities where air quality districts restrict diesel emissions.

The flagship platform#

• Turbocharged-aftercooled — the aftercooler (intercooler) brings intake charge temperatures down for consistent power output in high-ambient conditions
• 24 spark plugs — same V12 plug count as the KG300, but higher cylinder pressure demands more frequent ignition monitoring
• Container or walk-in enclosure recommended for all installations — the service envelope is large
• Paralleling-native — most KG400 installations are multi-unit arrays

When to use the KG400#

• Paralleling arrays where gaseous is mandated (BAAQMD, other air districts)
• Single-unit maximum gaseous for sites that need 250-320 kW continuous (80% loading)
• Campus distribution where multiple smaller diesel units would create multiple SPCC plans
• Sites with reliable gas service and strong gas pressure (minimum 2 PSI at the unit)

OnPoint service experience#

The KG400 is our largest gaseous service platform. Every KG400 we maintain is on a walk-in or container enclosure — there's no practical way to service a 21.9L V12 in a standard weather-protective cabinet. The aftercooler adds a service item (condensation drain, core inspection) that doesn't exist on the smaller naturally-aspirated or basic turbo units. Ignition service on 24 plugs across a V12 is a full-day job requiring two technicians.