The Kohler KG300 is a 300-kilowatt commercial standby generator — one of the largest single-unit gaseous gensets available in the North American market. It uses a turbocharged 18.0L V12 engine, delivering serious power without on-site fuel storage. At this capacity, the KG300 competes directly with 300 kW diesel units for campus, hospital, and large commercial applications.
The KG300 is the largest gaseous genset most facilities will consider before stepping into paralleled arrays or switching to diesel. Key characteristics:
24 spark plugs — ignition service is a significant labor event
Dual turbochargers on some configurations
Container enclosure option for large outdoor installations
Paralleling-ready — common to see 2-4 units in array for campus distribution
The KG300 V12 is a serious machine that demands experienced technicians. Spark plug service alone (24 plugs, access on both banks of a V12) is a half-day job. We recommend walk-in enclosures at minimum for any KG300 installation, and prefer container-style enclosures that allow full 360-degree access for the V12 service envelope.
Service intervals
Manufacturer-recommended intervals for the Kohler KG300 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.
Oil & filter
Every 500 hours or 12 months
Coolant change
Every 4000 hours
Air filter
Every 1000 hours
Spark plugs
Every 2000 hours
Major overhaul
≈ 24,000 hours
Load bank test
Every 12 months
Common failure modes
What we've seen fail on this platform. Use as a service-planning reference, not a diagnostic — actual failure modes depend heavily on duty cycle and maintenance history.
Component
Symptom
Typical hours
Severity
Turbocharger(s)
Oil in intake, reduced power, turbo whine
12,000+
moderate
Spark plugs (24 total)
Individual cylinder misfire under load
2,000+
minor
Intercooler system
Boost leak, reduced power output
8,000+
minor
Coolant pump
Weeping, bearing noise, overcooling at light load
15,000+
moderate
Parts cross-reference
oil Filter
Kohler GM62511
air Filter
Kohler GM62512
spark Plug
Champion RN14YC
starting Battery
Group 31 x2 (parallel)
Frequently Asked Questions
What is the standby power rating of the Kohler KG300?
The KG300 is rated 300 kW standby (270 kW prime) at 60 Hz. It uses a turbocharged 18.0L V12, the largest naturally-aspirated-class platform in the KG line.
Can the KG300 be paralleled?
Yes. Two or more KG300 units with APM603 paralleling controllers provide 600+ kW with N+1 redundancy. This is a common configuration for large campuses that prefer gaseous over diesel.
How does this compare to a 300 kW diesel?
A diesel 300 kW unit (like Kohler's own 300REOZDC) is more compact and doesn't depend on gas utility. But it requires on-site fuel storage, EPA SPCC plans, annual fuel polishing, and produces visible emissions. The KG300 eliminates all fuel-storage concerns but depends on gas utility reliability.
What ATS for 300 kW?
At 480V three-phase: 400-600A ATS. ASCO 7000 Series with bypass-isolation is the typical specification for critical facilities at this capacity.