500 kW standby · Natural Gas / LPG · Liquid-cooled
500 kW industrial gaseous standby generator. Generac's largest turbocharged SG Series unit for large hospitals, mission-critical facilities, industrial campuses, and paralleling arrays.
The Generac SG500 is a 500-kilowatt turbocharged natural gas and propane standby generator — the flagship of Generac's industrial SG Series. At this output, the SG500 serves large hospitals, major industrial operations, mission-critical facilities, and multi-building campuses where sustained gaseous standby at full commercial scale is required. Three-phase only, with voltage configurations through 346/600V, the SG500 integrates with the full range of North American industrial distribution systems.
The SG500 carries UL 2200 listing and NFPA 110 Level 1/2 compliance for life-safety and emergency standby applications. Steel enclosure options accommodate installations in noise-controlled or exposed outdoor environments. At this capacity, the SG500 also functions as a base unit in larger paralleled arrays where load demand or redundancy requirements exceed a single generator's output.
The SG500 represents the upper boundary of Generac's gaseous standby line, and at this capacity the conversation shifts decisively from equipment selection to service infrastructure. We recommend any SG500 installation be paired with a formal service agreement from a Generac-certified industrial dealer with documented emergency dispatch capability. Gas supply engineering, transfer switch sizing, and NFPA 110 compliance documentation require licensed engineering involvement. The turbocharged Generac industrial engine at this scale is reliable under a disciplined maintenance regimen; deferred maintenance at 500 kW carries outsized consequences for the facilities it protects.
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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
5,250,000 BTU/hr≈ 5250.0 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 SG500 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
Who is the Generac SG500 designed for?
The SG500 is designed for large facilities with significant gaseous standby requirements: major hospitals, large data centers with UPS primary systems, industrial campuses with on-site natural gas infrastructure, and universities or corporate campuses with centralized emergency power. At 500 kW, facilities typically have dedicated facilities staff and ongoing service agreements.
What are the natural gas supply requirements for a 500 kW gaseous generator?
A 500 kW natural gas generator requires a substantial gas supply — typically a dedicated high-pressure service from the utility or an appropriately sized on-site LPG system. Gas flow rate, supply pressure, and line sizing must be engineered by a licensed mechanical engineer specific to the installation. Do not assume existing building gas service can support this load.
How does the SG500 compare to using multiple smaller units in parallel?
A single SG500 reduces infrastructure cost (one transfer switch, one enclosure, one gas connection point) compared to a paralleled array of smaller units. However, paralleling two SG250 or SG300 units provides N+1 redundancy — if one unit fails, the other sustains partial load. The right approach depends on the facility's redundancy requirements and available physical space.
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400 kW industrial gaseous standby generator. Generac's turbocharged three-phase commercial natural gas/LP platform for large hospitals, mission-critical facilities, and paralleling arrays.