Seapower Marine is the UK main dealer for Cummins Onan Quiet Diesel™ marine generators, supplying the MDK series of generators from 4–29 kW across a wide range of specifications. Available configurations include single or three-phase output, 12 V or 24 V systems, negative or isolated ground, and both 50 Hz and 60 Hz models, allowing the generator to be specified to suit a wide variety of vessel installations.
In addition to the MDK Quiet Diesel range, we also supply larger Cummins Onan generator systems, including the MDCT series and the latest QSB7E-based generator sets, providing power outputs from 50 kW through to 150 kW for larger commercial and recreational vessels.
About the Cummins Onan Quiet Diesel™ Range
The Cummins Onan Quiet Diesel™ (QD) series is one of the most advanced marine generator ranges currently available. Designed specifically for marine applications, these generators combine dependable electrical output with quiet operation and modern digital control technology.
QD series generators feature Cummins Onan digital control systems, providing operators with clear, user-friendly diagnostic information. The integrated monitoring system continuously tracks generator performance, giving engineers and operators access to detailed operating data relating to both the engine and alternator. This allows potential issues to be identified quickly and helps ensure reliable onboard power management.
Generators within the Quiet Diesel range are available in both 50 Hz and 60 Hz configurations, with a selection of control panels and optional accessories available depending on the installation requirements. Cummins Onan marine generators are supported by a worldwide limited warranty of up to five years or 2000 operating hours, providing reassurance for vessel operators.
Detailed product specifications, manuals and technical information can be found on our Technical Resources page.
Technical Support
Seapower Marine provides technical support for Cummins Onan marine generators around the world. Our engineers regularly assist vessel owners, operators and marine engineers with troubleshooting and diagnostics via telephone and video support, helping resolve issues quickly without the need for unnecessary travel or delays.
This remote support capability allows us to assist vessels operating anywhere in the world, providing guidance on diagnostics, fault finding, configuration and general generator operation.
Installation Reviews
Correct installation of a marine generator is essential for both reliable operation and warranty compliance. Cummins Onan generators have specific installation requirements, particularly regarding cooling water flow, exhaust systems, ventilation and electrical connections.
Seapower Marine can provide installation advice and technical guidance for owners or independent boat builders installing a generator. We are also able to undertake installation reviews to ensure the generator has been installed in accordance with Cummins Onan requirements.
Service and Repair
We provide service, maintenance and repair support for Cummins Onan marine generators, including diagnostics, routine servicing and fault rectification.
Our engineers can also assist with generator winterisation procedures, similar to those carried out on vessel propulsion engines, ensuring the generator remains protected during extended periods of inactivity.
Load-Bank Testing
Seapower Marine offers professional load-bank testing for marine generators, confirming that the generator performs correctly under electrical load. This service is always carried out before installation or following repairs.
Following testing we can provide full test documentation and video footage, giving customers confidence that the generator is operating correctly before returning to service.
Generator PCB Configuration
Each Cummins Onan generator contains an onboard control PCB that is configured to specific operational parameters before leaving the factory. In some cases repeated use of the control panel can alter these settings, which may prevent the generator from operating correctly without necessarily generating a fault code.
If you suspect the control configuration has changed, Seapower Marine can provide guidance and detailed instructions to reconfigure the control system and restore normal generator operation. New PCB are available from stock and are always programmed before dispatch.
Model Identification
Owners of older Cummins Onan generator sets may notice that earlier models were designated with part numbers such as MDKB ‘X’, whereas newer models appear as MDKDK or similar.
In many cases the generator itself remains fundamentally the same, with the additional letter simply indicating compliance with updated emissions regulations in the United States. If you are unsure about the specification of your generator or require assistance identifying the correct model, please contact the Seapower Marine team.
Need advice on a Cummins Onan generator?
Seapower Marine can assist with generator supply, diagnostics, spare parts and technical support for the full range of Cummins Onan marine generators.