The Cummins C250 N6 is a 250-kilowatt natural gas and propane commercial standby generator — one of the larger units in Cummins' C-Series gaseous portfolio. The turbocharged gaseous engine supports medium-to-large commercial facilities, medium hospitals, and industrial sites that prefer gaseous fuel over on-site diesel storage.
At 250 kW, this unit is well-suited to facilities that require significant standby capacity but have constraints on diesel fuel storage or operate in areas where natural gas supply is stable and reliable. The three-voltage, three-phase output configuration covers the full range of commercial electrical systems from standard low-voltage services through 600V Canadian distribution.
The C250 N6 handles demanding commercial standby loads where gaseous fuel is the preferred choice. On turbocharged gaseous units at this size, turbocharger health and air/fuel calibration are the primary maintenance focus points. Gas supply pressure validation is critical at commissioning and should be re-verified any time utility distribution changes occur upstream of the installation.
Request a quote
Get pricing & lead time on the Cummins C250 N6
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
2,625,000 BTU/hr≈ 2625.0 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 Cummins C250 N6 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
Can C250 N6 units be paralleled?
Yes. Cummins' PowerCommand controllers support paralleling of multiple C-Series units, enabling scalable gaseous standby arrays. Two paralleled C250 N6 units can deliver 500 kW — useful for facilities that need capacity beyond a single unit or require N+1 redundancy in a natural gas standby system.
How does the C250 N6 compare to the Generac SG250?
Both are 250 kW three-phase natural gas standby generators. The C250 N6 uses Cummins' vertically integrated engine and PowerCommand controller. The Generac SG250 uses a different gaseous engine platform. Cummins' advantage in Northern California is service network density and single-source warranty coverage across engine, alternator, and controller.
What is the gas supply pressure requirement for the C250 N6?
Turbocharged gaseous engines at this power level typically require 7–11 in. W.C. (water column) inlet pressure at the engine fuel train. Specific requirements vary by model configuration — confirm with Cummins' installation specification sheet and verify available utility gas pressure before finalizing the design.
Similar models
C
Cummins
New
Cummins C200 N6
200 kW standby · Natural Gas / LPG · Liquid-cooled
200 kW natural gas/propane commercial standby generator. Cummins' flagship gaseous unit with QSJ8.9G engine and PowerCommand 2.3 controller.