50 kW Cummins Natural Gas Generator

This 50 kW generator runs on natural gas from a Cummins LYB3.9-G70 spark-ignited engine: an in-line four-cylinder, four-stroke design with electronic ignition, an 11.9:1 compression ratio, a pre-mix gas mixer and an electronic governor. It is rated 50 kW prime and 55 kW standby, with a Stamford S1L2-R1 brushless alternator with automatic voltage regulation and a Deep Sea DSE6120 controller.

The spec sheet’s rating table lists 220V, 60 Hz, single-phase output at 227 A, and it notes that the output voltage is built to the customer’s requirements, with options of 380/220V, 400/230V, 415/240V, 440/254V or 220/110V. Its description line also mentions a 50 Hz 220/380V three-phase build. Tell us your service voltage, phase and frequency and we will confirm the configuration before you order.

Why choose natural gas

A natural gas generator draws fuel from the utility gas line, so there is no tank to fill and no stored fuel to manage, and runtime is limited by the gas service rather than tank size. That suits commercial buildings, multi-family properties and homes that already have gas. The trade-off is that you depend on the gas supply and need a meter and piping sized for the generator.

Gas supply requirements

The spec sheet calls for a supply pressure of 0.8–30 kPa and dry, clean gas (H₂S below 20 ppm, dust below 5 µm, tar below 10 ppm). It lists consumption of 0.3 m³ per kWh, about 15 m³ of gas per hour at the full 50 kW load. Rated conditions are below 1,000 m altitude and 40 °C ambient temperature.

Power quality

Listed electrical performance includes steady-state voltage regulation within ±1%, steady-state frequency regulation within 1%, and frequency recovery within 5 seconds after a sudden load change.