Overview#
The Cummins C175 N6 is a 175 kW (219 kVA) standby natural gas generator set built on the GTA 8.3G engine -- an 8-liter, inline-6-cylinder platform featuring a cast iron block with replaceable wet cylinder liners. This is a commercial-class engine architecture used across the 115-175 kW Cummins gas genset range. The C175 N6 delivers full standby output at 0.8 power factor tested per NFPA 110.
The C175 N6 is positioned as a higher-output commercial and light-industrial standby unit, filling the gap between the QSJ8.9G-powered 125 kW class and the inline-6 855 cubic inch engines used at 250-300 kW. Its GTA 8.3G engine uses a 24-volt starting system with two 8D batteries and a 43-amp battery charging alternator -- a step up from the 12V systems used on the smaller N6 models. The alternator is a brushless, 4-pole, drip-proof revolving field design with 2/3 pitch stator winding and Class H insulation per NEMA MG1-1.65.
The control system is PowerCommand 1.1, which provides digital voltage regulation, isochronous governing, automatic remote start/stop, AmpSentry protection (optional upgrade to PowerCommand 2.2 available), and NFPA 110 capability. The unit is manufactured under ISO 9001:2015 controls and is compatible with a full range of Cummins enclosure options including weather-protective and sound-attenuated Level I and Level II enclosures.
Technical Specifications#
| Parameter | Value |
|---|---|
| Standby Rating | 175 kW (219 kVA) |
| Continuous Rating | 115 kW (144 kVA) |
| Frequency | 60 Hz |
| Power Factor | 0.8 |
| Engine Model | GTA 8.3 |
| Displacement | 8 L (488 in³) |
| Configuration | Cast iron, in-line 6, wet cylinder liners |
| Aspiration | Spark-ignited |
| Overspeed Limit | 2100 rpm |
| Cranking Current | 900 CCA at -18 C (0 F) |
| Starting Voltage | 24V, negative ground |
| Battery Type | 8D x 2 |
| Battery Charging Alternator | 43 amps |
| Lube Oil Filter | Spin-on canister, full flow with bypass |
| Standard Cooling | 38 C (100 F) limiting ambient temperature, open set |
| Control | PowerCommand 1.1 |
| Alternator Insulation | Class H, NEMA MG1-1.65 |
| Alternator Temperature Rise | 125 C standard |
| Dimensions (L x W x H) -- Standby | 115 x 40 x 59 in (2,921 x 1,016 x 1,499 mm) |
Natural gas fuel consumption (CFH) -- Standby rating:
| Load | CFH |
|---|---|
| 25% | 848 |
| 50% | 1,217 |
| 75% | 1,708 |
| 100% | 2,202 |
Fuel inlet pressure at the Maxitrol regulator inlet: 14 to 20 in WC (356 to 508 mm WC).
Full-load amperage (FLA) at standby rating -- three-phase, 0.8 PF:
| Voltage | FLA |
|---|---|
| 120/208V | 607 |
| 127/220V | 574 |
| 139/240V | 526 |
| 220/380V | 332 |
| 240/416V | 304 |
| 254/440V | 287 |
| 277/480V | 263 |
| 347/600V | 210 |
Our Service Experience#
The GTA 8.3G's wet cylinder liner design is the primary long-term maintenance concern on this platform. Proper coolant treatment with supplemental coolant additives (SCA) is essential to prevent cavitation erosion of the liners -- a failure mode that can allow coolant to enter the combustion chamber and cause white exhaust smoke and rapid coolant loss. We recommend following Cummins' coolant maintenance schedule precisely, including SCA concentration checks at each oil change interval.
The 24V two-battery starting system (two 8D batteries) is more capable than the 12V systems on the smaller N6 models, but the batteries still require annual load testing and typically need replacement at 4-5 year intervals in commercial standby service. The Maxitrol regulator requires periodic inspection and calibration -- fuel inlet pressure must be maintained at 14-20 in WC under operating load conditions. The limiting ambient temperature of 38 C (100 F) in open configuration is lower than the 50 C rating on the QSJ5.9G and QSJ8.9G units; installations in hot climates or confined spaces should be carefully evaluated for adequate cooling air.
Frequently Asked Questions#
What is the standby rating of the C175 N6? 175 kW (219 kVA) at 60 Hz, 0.8 power factor, per Emergency Standby Power (ESP) rating in accordance with ISO 8528 and NFPA 110. The continuous (prime) rating is 115 kW (144 kVA).
What engine does the C175 N6 use? The Cummins GTA 8.3 -- an 8-liter, in-line 6-cylinder, spark-ignited natural gas engine with a cast iron block featuring replaceable wet cylinder liners. This is a larger platform than the QSJ5.9G and QSJ8.9G used in the smaller N6 models. Overspeed limit is 2100 rpm.
How much natural gas does the C175 N6 consume? At 100% standby load: 2,202 CFH. At 75%: 1,708 CFH. At 50%: 1,217 CFH. At 25%: 848 CFH. Fuel inlet pressure must be maintained at 14 to 20 in WC (356 to 508 mm WC) at the Maxitrol regulator inlet under all operating conditions.
What voltages does the C175 N6 support? Three-phase configurations: 120/208V, 127/220V, 139/240V, 220/380V, 240/416V, 254/440V, 277/480V, and 347/600V. The alternator features a brushless, 4-pole, 2/3 pitch design with Class H insulation and Shunt or PMG excitation (PMG optional).
What control system does the C175 N6 use? PowerCommand 1.1 as standard, with an optional upgrade to PowerCommand 2.2 with AmpSentry protection. The control provides isochronous governing, digital voltage regulation, cycle cranking, PCCNet interface, and NFPA 110 Level 1 compliance capability. The InPower service tool supports diagnostics and configuration via RS-485.
What is the limiting ambient temperature for the C175 N6? 38 C (100 F) in an open (skid-mounted) configuration. Enclosures can reduce the effective limiting ambient temperature by a few degrees. Installations in high-temperature environments should include a cooling performance analysis. The C175 N6 open-set dimensions are 115 x 40 x 59 in (standby configuration).
