Overview#
The Cummins C500 N6 is a 500 kW (625 kVA) standby natural gas generator set built on the GTA 28E -- a 28-liter, V12, spark-ignited engine producing 770 bhp (574 kWm). This is the highest-output model in the standard Cummins N6 gas standby series below the C750 and C1000 class, and the only model in the line that uses a V12 engine architecture. The 1,709 cubic inch displacement gives the GTA 28E a highly conservative power density for this output class, which directly translates to long service life and a 30,000-hour major overhaul interval.
The C500 N6 operates at 1800 rpm with an overspeed trip at 2200 rpm -- a higher overspeed limit than the 2100 rpm used on the inline-6 GTA 855E powering the C300. The 24-volt starting system requires a minimum of 1800 CCA cranking current, reflecting the larger engine displacement. The engine also incorporates regenerative power capability of 75 kW. The alternator is an HCI504D (ADS #306, HC5 frame) brushless, 4-pole revolving field design with PMG excitation and Class H insulation. The control system is PowerCommand 3.3 MLD, providing isochronous governing, digital voltage regulation, AmpSentry protection, PCCNet communications, and NFPA 110 Level 1 compliance capability. A circuit breaker (Li frame, 800A 100% RIGHT, rated 600/525V) is included as standard.
The C500 N6 is EPA-certified for both stationary emergency (40 CFR 60) and stationary non-emergency applications. A Sound Level 2 enclosure option is available (dimensions 305 x 90 x 126 in with enclosure). Open set wet weight is 7,620 lbs (3,456 kg).
Technical Specifications#
| Parameter | Value |
|---|---|
| Standby Rating | 500 kW (625 kVA) |
| Frequency | 60 Hz |
| Power Factor | 0.8 |
| Engine Model | GTA 28E |
| Displacement | 1,709 in³ (28 L) |
| Configuration | V12 |
| Bore x Stroke | 5.6 in x 6.0 in (141 mm x 152 mm) |
| Compression Ratio | 8.5:1 |
| Gross Engine Output | 770 bhp (574 kWm) |
| BMEP | 198 psi (1,365 kPa) |
| Regenerative Power | 75 kW |
| Rated Speed | 1800 rpm |
| Overspeed Limit | 2200 rpm |
| Lube Oil Capacity | 72 qt (68 L) |
| Starting System | 24V, negative ground |
| Minimum Cranking Current | 1400 CCA |
| Battery Charging Alternator | 43 amps |
| Alternator Model | HCI504D (ADS #306, HC5 frame) |
| Alternator Excitation | PMG |
| Alternator Insulation | Class H |
| Control | PowerCommand 3.3 MLD |
| Circuit Breaker | Li frame, 800A 100% RIGHT, 600/525V |
| Dimensions (L x W x H) -- Open Set | 166 x 82 x 98 in (422 x 208 x 249 cm) |
| Dimensions (L x W x H) -- SL2 Enclosure | 305 x 90 x 126 in |
| Wet Weight -- Open Set | 7,620 lbs (3,456 kg) |
Natural gas fuel consumption (CFH) -- Standby rating:
| Load | CFH |
|---|---|
| 25% | 2,452 |
| 50% | 3,839 |
| 75% | 5,413 |
| 100% | 6,994 |
Fuel inlet pressure: 10 to 20 in WC at the engine fuel inlet connection.
Our Service Experience#
The GTA 28E's V12 architecture means spark plug service involves 12 cylinders -- double the count of the inline-6 models in the N6 series. Schedule spark plug service intervals carefully and use OEM-specified plugs, since a misfire on any one cylinder under load is more difficult to diagnose on a 12-cylinder engine without per-cylinder monitoring via the InPower service tool. The 72-quart oil capacity requires full-capacity oil change planning: budget for proper collection equipment and confirm that your service provider brings adequate oil volume to the site for each 500-hour change.
The 1400 CCA minimum starting requirement is substantial -- both batteries must meet this CCA rating individually, and we recommend annual load-bank testing of the starting circuit under simulated cranking conditions. The fuel inlet pressure specification is 10-20 in WC, which has a lower minimum (10 in WC) compared to the 14 in WC required on the C300 -- confirm with the utility or gas supplier that dynamic pressure at the engine inlet remains within this range at full load.
Frequently Asked Questions#
What is the standby rating of the C500 N6? 500 kW (625 kVA) at 60 Hz, 0.8 power factor, per Emergency Standby Power (ESP) rating in accordance with NFPA 110. The unit is also EPA-certified for stationary non-emergency applications.
What engine does the C500 N6 use? The Cummins GTA 28E -- a 1,709 in³ (28-liter), V12, spark-ignited natural gas engine. Bore is 5.6 in (141 mm), stroke is 6.0 in (152 mm), compression ratio is 8.5:1, gross output is 770 bhp (574 kWm). Overspeed limit is 2200 rpm. The engine includes 75 kW regenerative power capability.
How much natural gas does the C500 N6 consume? At 100% standby load: 6,994 CFH. At 75%: 5,413 CFH. At 50%: 3,839 CFH. At 25%: 2,452 CFH. Fuel inlet pressure must be maintained between 10 and 20 in WC at the engine fuel inlet connection under all operating conditions.
What control system does the C500 N6 use? PowerCommand 3.3 MLD, providing isochronous governing, digital voltage regulation, AmpSentry protective relay, PCCNet communications, auto start/stop, output metering, and NFPA 110 Level 1 compliance capability. InPower service tooling connects via RS-485 for diagnostics and configuration.
What does the C500 N6 weigh and how large is it? Open set wet weight is 7,620 lbs (3,456 kg). Open set dimensions are 166 x 82 x 98 in (422 x 208 x 249 cm). With the optional Sound Level 2 enclosure, dimensions increase to 305 x 90 x 126 in.
What voltages does the C500 N6 support? Three-phase configurations at 60 Hz: 120/208V, 127/220V, 139/240V, 220/380V, 240/416V, 254/440V, 277/480V, and 347/600V. The PMG-excited HCI504D alternator (HC5 frame, Class H) supports field voltage configuration across this range.
