The Generac SG300 is a 300-kilowatt turbocharged natural gas and propane standby generator from Generac's industrial SG Series. At this capacity, the SG300 competes directly with the Kohler KG300 for large commercial buildings, medium hospital facilities, multi-building campuses, and industrial operations that need code-compliant gaseous standby power. Three-phase only, the SG300 is configured for the distribution systems typical of facilities at this scale.
The SG300 carries UL 2200 listing and NFPA 110 Level 1/2 compliance, supporting life-safety and emergency standby permitting. Steel enclosures — sound-attenuated and weather-protective — are available for installations in noise-sensitive or exposed locations. Generac's Power Zone controller includes digital metering, Modbus communication, and Mobile Link remote monitoring support.
The 300 kW gaseous class is a serious commitment: facilities at this scale typically run service contracts and require 24/7 emergency dispatch capability. Generac's industrial dealer network at this capacity tier is thinner than Kohler's or Cummins' in some regions — we recommend verifying local industrial dealer coverage and emergency parts stocking before specifying. The turbocharged Generac industrial engine is capable; planned maintenance on ignition systems and turbocharger condition is essential to sustain readiness at this output level.
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Tell us about the application — kW, voltage, application, install timeline — and we'll respond within one business day with budgetary pricing, lead time, and any sizing notes.
Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.
Estimate runtime on this tank
Fuel demand at 75% load
3,150,000 BTU/hr≈ 3150.0 cf/min @ 1,000 BTU/cf
On utility natural gas the runtime is generally unlimited provided the supply line and meter can deliver this BTU/hr at the engine's required inlet pressure (typically 5–14" WC residential, up to 5 psi commercial). Confirm against the OEM's published fuel-pressure spec.
Service intervals
Manufacturer-recommended intervals for the Generac SG300 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.
Oil & filter
Every 250 hours or 12 months
Coolant change
Every 4000 hours
Air filter
Every 1000 hours
Spark plugs
Every 1500 hours
Major overhaul
≈ 15,000 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
Loss of power, excessive smoke under load
12,000+
moderate
Spark plugs / ignition
Misfire at load, rough running
1,500+
minor
Charge air cooler
Reduced power output, elevated intake temps
10,000+
moderate
Battery
Failed to start during outage
8,760+
minor
Frequently Asked Questions
How does the Generac SG300 compare to the Kohler KG300?
Both are 300 kW turbocharged gaseous standby generators at 1800 RPM targeting the same large commercial and industrial market. Kohler's KG300 benefits from deep integration with the Kohler ATS product line and a well-established industrial dealer network. The Generac SG300 typically carries a lower acquisition cost and pairs with Generac's Mobile Link monitoring platform. The right choice often depends on the facility's existing generator fleet and local dealer service capability.
What facilities typically specify 300 kW gaseous standby?
Medium hospitals (non-life-safety wings), large hotels, multi-building university or corporate campuses, data centers with primary UPS systems, and heavy manufacturing facilities with on-site natural gas infrastructure are the most common 300 kW gaseous standby applications.
Is the SG300 suitable for NFPA 110 Level 1 applications?
The SG300 carries NFPA 110 Level 1/2 compliance, which means it meets the performance requirements for life-safety standby applications when installed and maintained per NFPA 110 standards. Specific authority-having-jurisdiction (AHJ) approval is required for life-safety installations.
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