Overview#
The Cummins C650 N6 is a 650 kW (813 kVA) standby natural gas generator set powered by the GTA38 gas engine -- a turbocharged and aftercooled spark-ignited engine. This is the higher-output configuration of the same GTA38 platform used in the C600 N6. The unit runs on natural gas or propane vapor (field selectable) and is equipped with PowerCommand controls providing isochronous governing and AmpSentry alternator protection.
The C650 N6 serves large commercial and industrial standby applications where the additional 50 kW over the C600 N6 provides margin for full-building backup. Common installations include hospitals, data centers, large office complexes, and manufacturing facilities where natural gas service eliminates the need for diesel fuel infrastructure.
Technical Specifications#
| Parameter | Value |
|---|---|
| Standby Rating | 650 kW (813 kVA) |
| Frequency | 60 Hz |
| Power Factor | 0.8 |
| Engine Model | GTA38 |
| Fuel Type | Natural gas / LPG |
| Cooling | Liquid |
| Aspiration | Turbocharged and aftercooled |
| Rated Speed | 1800 rpm |
| NG Fuel Consumption (Full Load) | ~6,500 CFH |
Our Service Experience#
The GTA38 at the 650 kW rating runs at the top end of its output range, which makes air-fuel mixture calibration and gas pressure regulation particularly critical. Any deviation in gas supply pressure or air-fuel ratio is more noticeable at maximum output. We pay close attention to turbocharger condition and boost pressure during annual service on the C650 N6 -- the engine is working harder than the C600 N6 variant, so turbo wear patterns emerge slightly earlier.
Gas supply infrastructure must be sized for approximately 6,500 CFH at full load. A dedicated high-capacity gas meter, 3-inch minimum supply piping, and properly sized pressure regulator are essential. Dynamic pressure verification under full load is mandatory during commissioning and annual service.
Frequently Asked Questions#
What engine does the C650 N6 use? The Cummins GTA38 -- the same platform as the C600 N6, rated at 650 kW standby through engine calibration differences.
What is the standby rating of the C650 N6? 650 kW (813 kVA) at 60 Hz, 0.8 power factor. Emergency Standby Power (ESP) rating.
What are the service intervals? Oil and filter at 500 hours or 12 months. Air filter at 500 hours. Spark plugs at 1,000 hours. Major overhaul at 30,000 hours.
Can PowerGen service the C650 N6 in Northern California? Yes. PowerGen provides authorized Cummins natural gas generator service across the San Francisco Bay Area, Silicon Valley, and Northern California.
