Cumins is the world's largest diesel engine manufacturer. It can be found in all industrial sectors on land, but also in the marine sector. Its range goes from 2.8 to 95 litres of displacement! We don't often see it, because this American brand sells its engines to machine manufacturers (trucks, buses, construction machines...) who put their own brand on them.
Oman is a generator brand acquired by Cummins 25 years ago. Its major market share is in terrestrial generators sold in cocoon and used as a back-up solution in homes or to supply isolated points. In the yachting industry, these groups are also used by all major shipyards.
In France, Onan has an 85% market share. Almost all major construction sites call on him: Jeanneau, Bénéteau, Amel, Amel, Lagoon, Fountaine Pajot, Nautitech, Catana... Onan generators have very good press, known for their reliability and ease of installation.
Demands from larger powers
These groups are increasingly used with larger and larger powers. Indeed, the size of the boats tends to increase, and these boats are more and more equipped. Thus, from 40 feet, a group often becomes standard equipment. To meet this power demand, Onan has a range of generators starting at 4 kW. In pleasure boating, models from 4 to 29 kW are used. Groups from 30 to 65 kW are more likely to be found on yachts and super yachts.
Onan uses the same products for all markets. Thus a yachtsman will be equipped with the same group as the one used intensively by the military, for example. This is an important point, especially for boats that are rented, where there is often a group that runs 14 hours a day to ensure the air conditioning on board.
Kubota inside
To power its "small" power groups, Cummins, which does not have a small enough engine block, uses Kubota. The engines, depending on the power ratings, range from 2 to 4 cylinders. The coupled generators are always Onan. They are installed in parallel (to save space) on small models or in series from 7 kW.
The groups are all delivered with their soundproof cocoon. That's what makes Onan so special, they're very quiet. No more than 65 dB at full load (measured at 1m). The technical choice was made to run the engines at low rpm (1500 rpm to produce 50 HZ). An electronic processor regulates the engine speed according to the required load by playing on the injection pump. Onan ensures signal stability with this electronic regulation with less than 1% frequency and voltage difference.
The generator is air-cooled. This technical choice makes it a little more voluminous and heavy with large copper windings on the rotor and stator, but this avoids the risk of flooding an area reserved for electricity.
Very quiet
For installation the generator set is delivered in its cocoon ready for operation. The connections (engine cooling water, exhaust and electrical connections) are all assembled on one side face. When ordering, you can even choose whether you want these connections on the right or left of the cocoon. The control panel of the unit is located on the cocoon, but it can also be moved to the chart table for example.
For maintenance, Onan has launched a Cruise Kit, a case that contains all the spare parts to monitor the generator set (filters, belts, pump wheels, etc.). In addition, Onan is present via Cumins all over the world, thus facilitating after-sales service.
