Overview#
The Cummins C25 D6 (model designation C25D6) is a 25 kW standby diesel generator set powered by the Cummins 4BT3.3-G5 engine -- a 3.3-liter, turbocharged, 4-cylinder industrial diesel running at 1800 rpm. Rated at 31.2 kVA standby and 28.3 kVA prime at 60 Hz, the C25D6 is the entry point into Cummins-block diesel generators, stepping up from the Kubota-powered C20D6.
Standard equipment includes the PowerCommand 1.1 control with integrated voltage regulation and a sound-attenuated enclosure. The unit is EPA Tier 3 certified for stationary emergency standby applications. The 4BT3.3 engine platform is shared across the C25 through C60 range, providing parts commonality and service familiarity across the small-to-mid diesel lineup.
The C25D6 is designed for small commercial standby applications including retail stores, small offices, and branch facilities where natural gas may not be available or where diesel fuel storage is preferred.
Our Service Experience#
The 4BT3.3-G5 is the starting point of the Cummins B-series in the generator lineup. At 25 kW, the engine is lightly loaded relative to its displacement, which generally means long service life and low stress on components. The turbocharger oil seals are the most common wear item we monitor -- check for blue smoke during the weekly exercise cycle. Fuel quality is important on low-utilization units; use fuel stabilizer treatments if the generator exercises fewer than 30 minutes per week.
Frequently Asked Questions#
What fuel tank options are available for the C25D6? The C25D6 is typically available with a sub-base fuel tank integrated into the sound-attenuated enclosure. Tank sizes vary by configuration. Contact your Cummins distributor for specific options.
Is the C25D6 UL listed? The C25D6 is available in UL 2200 listed configurations for permanent standby installations. Confirm the specific listing with your distributor when ordering.
