Cummins QD 11.5MDKDM-8138A

Description

Featuring a four-cylinder 1.498-liter diesel base, the Cummins Onan QD 11.5MDKDM Marine Generator produces 11.5 kW continuous single-phase electrical output at 1,500 RPM. This quiet diesel package pairs digital voltage regulation with closed heat exchanger freshwater cooling to support air conditioning chillers, navigation electronics, and galley equipment aboard mid-sized motor yachts without voltage drops.

A rigid cast iron block integrates four in-line cylinders to absorb mechanical harmonic stress within enclosed marine machinery spaces. The rotating group features a heat-treated forged alloy crankshaft, forged steel connecting rods, and oil-cooled aluminum pistons. Engine geometry measures a 78 mm bore, 78.4 mm stroke, 23:1 compression ratio, 4.5-quart oil pan volume, and total dry weight of 745 lbs inside its acoustic aluminum sound enclosure.

Key Features of Cummins Onan QD 11.5MDKDM

Yacht owners buy Cummins Onan QD 11.5MDKDM generator packages to upgrade aging auxiliary gen-sets inside tight cruiser engine compartments. This 50 Hz power unit furnishes steady 230-volt current to eliminate shore power dependence during offshore passages.

• 11.5 kW continuous single-phase electrical output powers heavy salon air conditioning compressors and galley induction cooktops.
• Four-pole brushless revolving field alternator utilizes digital voltage regulation to hold steady 230-volt AC current.
• Sealed sound attenuation housing suppresses operating sound emissions down to 65 decibels at one meter.
• J1939 CAN-bus digital controls monitor oil pressure, coolant temperature, exhaust heat, and engine speed.
• 11.5MDKDM marine generator automatic shutdown sensors halt operation upon detection of raw water flow restriction or overspeed.
• Cupronickel tube heat exchanger cooling maintains uniform internal engine block temperatures in warm tropical seawater.
• Water-cooled cast iron exhaust elbow isolates heat from fiberglass boat structures.

Digital Alternator Power Output

This four-stroke marine gen-set maintains a constant 1,500 RPM operating speed to generate 50 Hz electrical frequency. Continuous load ratings output 11.5 kW and 50 amps at 230 volts single phase with a 1.0 power factor. Fuel consumption averages 0.77 gallons per hour under 50 percent load and 1.37 gallons per hour at full continuous output. The pressurized engine lubrication circuit maintains 35 to 55 PSI hot oil pressure under continuous run cycles, keeping main bearing journals isolated from metal-to-metal contact during rough offshore navigation.

Sound Enclosure Hull Fitment

The sound shield package measures 40.7 inches long, 22.2 inches wide, and 23.4 inches high, dropping between narrow bilge stringers. Four elastomeric marine mounts isolate hull vibration. Single-side service access places oil dipsticks, fuel filters, and the raw water impeller behind one latching panel, requiring five inches of side clearance for hand maintenance access.

Quiet Diesel Preventive Maintenance

Prime fuel lines through the mechanical lift priming lever to purge air bubbles before initial startup. Check coolant expansion tanks to maintain correct freshwater volume. This marine gen-set is not engineered for dry exhaust land installations, raw seawater cylinder block circulation, or 60 Hz 120-volt wiring grids without stator reconnection.

• Drain factory break-in lube oil and install fresh spin-on oil filters after the initial 50 operating hours.
• Inspect raw water pump rubber impellers and replace primary fuel filter elements every 250 operating hours.
• Flush heat exchanger seawater passages and evaluate sacrificial zinc anodes every 12 months.

Factory Warranty Crate Inventory

Cummins Onan backs this marine generator package with a comprehensive 24-Month / 2,000-Hour limited warranty. The wooden transport crate contains the complete marine generator, sound attenuation enclosure, remote digital display panel, flexible fuel line kit, factory load test sheet, and technical operator maintenance documentation binder.