HomeCummins/OnanCummins/Onan 45.0 DEF-3R

Cummins/Onan 45.0 DEF-3R Generator Set

The Cummins/Onan 45.0 DEF-3R is a 45 kW (56.25 kVA) diesel standby generator set powered by a Ford 2713E engine. It is available at 120/240 V, single-phase and 60 Hz. It holds about 13.25 L (3.5 gal) of oil and 17 L (4.5 gal) of coolant.

45 kW
Standby
5.93 L
Displacement
13.25 L
Oil capacity
0
Document types

How to read your Cummins/Onan serial & model number →

Typical fuel consumption for 45–50 kW Diesel generators →

Compare with other 45–50 kW Diesel generators →

Service parts for the 45.0 DEF-3R

Grouped by system, with how many of each the parts manual calls for.

Air intake

1 required
140-1089Air filtersee priceAmazon

Belts

1 required
511-0084Beltsee priceAmazon

Cooling system

1 required
130-0775Coolant filtersee priceAmazon

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

Fueldiesel
Frequency60.0 Hz
Standby power45 kW
Standby kVA56
Oil capacity13.25 L
AlternatorUR (3-lead)
Voltage options120/240 V
Phase1
Power factor0.8

Engine

Ford 2713E
Oil capacity13.25 L
Coolant capacity17.0 L
Displacement5.93 L
AspirationNatural
Rated speed1800 rpm

Filters & service parts

model family
ItemSpecCapacityPart #Interval
Air filter140-1089 Amazon eBay
Fuel filter
Oil filter
BatteryElectrolyte specific gravity 1.265 at 80 F (26.7 C)
Belt511-0084 Amazon eBay
CoolantClean soft water with rust and scale inhibitor; ethylene glycol base antifreeze where freezing possible17.0 litres
Coolant filterFor use with plain water and selected antifreezes130-0775 Amazon eBay
OilAPI CC/CD; SAE 5W-20, 10-10W, 20-20W, 30 or 40 by ambient temperature13.25 litres

Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number.

Service specifications

21
TypeItemValueUnitCondition
AdjustmentBattery electrolyte specific gravity1.265specific gravityat 80 F (26.7 C), full charge
AdjustmentFan belt tension1/2-inch (12.5 mm) depression between pulleysmm
OtherCompression ratio16.0:1ratio
OtherEngine horsepower loss at altitudeapproximately 3 percent for each 1000 feet (305 m)%above sea level
OtherOil pressure time delay12.5seconds (approximately)
OtherRated altitudeup to 1000feet (305 m)standard cooling, normal ambients, No. 2 Diesel
OtherStandard cranking time limit75seconds
PressureLow oil pressure shutdown setpoint14psi (96.5 kPa)
PressureMaximum permissible exhaust restriction (back pressure)20.4-inches H2O (5.1 kPa)kPa
PressureNormal engine oil pressure30 to 55psi (207 to 380 kPa)after start
SpeedGenerator frequency regulation3Hz Max. No Load to Full Load
SpeedGovernor regulation5% Maximum%
SpeedOverspeed shutdown setpoint2100rpm
TemperatureCity water cooled temperature range170 to 200F (76.7 to 93.3 C)adjustable flow valve
TemperatureHeat exchanger / standpipe cooling water temperature165 to 195F (73.9 to 90.6 C)adjust rate of flow valve
TemperatureHigh engine temperature shutdown setpoint215F (102 C)
TemperatureNormal water temperature180 to 195F (82 to 90.6 C)after 10 minutes under load
TorqueFuel filter bleed screw torque5-7lb-ft (6.88 to 9.5 N·m)
TorqueFuel injection pump bleed screw torque3-5lb-ft (4.1 to 6.8 N·m)
TorqueRotating rectifier diode torque30in. lb (3.4 N·m) or finger tight plus a quarter turn
VoltageAC voltage regulation±2%no load to full load, 0.8 PF

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
CoolantClean soft water with rust and scale inhibitor; ethylene glycol base antifreeze where freezing possible17.0 litresNominal capacity 18-quarts (17-litres) including radiator
Engine oil5W-20API CC/CDbelow -23°C13.25 litresBelow -10 F (-23 C)
Engine oil10-10WAPI CC/CD-23°C to 4°C13.25 litres-10 F to +40 F (-23 C to 4.5 C)
Engine oil20-20WAPI CC/CD4°C to 21°C13.25 litres40 F to 70 F (4.5 C to 21 C)
Engine oil30API CC/CD21°C to 38°C13.25 litres70 F to 100 F (21 C to 38 C)
Engine oil40API CC/CDabove 32°C13.25 litres90 F and above (32 C)
FuelASTM No. 2 DieselMinimum Cetane rating of 43; maximum Sulphur content of 0.40Filter or strain fuel when filling tank; keep fuel clean

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

11
Governor Speed Adjustment adjustment

Tools: Screwdriver, Wrenches

  1. Loosen lock nuts on idle stop screw and maximum speed stop screw.
  2. Start engine; apply full load.
  3. Back off maximum speed stop screw (screwdriver slot).
  4. Turn idle speed stop screw clockwise until frequency meter indicates 60 Hz (counterclockwise reduces rpm).
  5. Turn maximum speed stop until it bottoms on governor control lever.
  6. Secure lock nuts.
Stop-Solenoid Linkage Adjustment adjustment
  1. Remove the joint attaching the stop solenoid rod to injection pump arm.
  2. With engine running, move lever arm on injection pump back slowly toward radiator just until engine stops.
  3. Hold lever in this position and adjust linkage accordingly.
  4. Snap rod joint back on injection pump arm.
Battery Connection installation

⚠ Do not smoke while servicing batteries.

  1. Use two 6-volt batteries for a normal installation.
  2. Connect the batteries in series (negative post of first battery to positive post of second).
  3. Use the battery cables provided on the unit.
Generator Voltage Reconnection installation

⚠ A qualified electrician or authorized service representative must perform installation and all service.

  1. Remove either right, left or top panel from control box.
  2. Connect wires T1 through T12 together as shown on panel drawing and Figure 1 for voltage desired.
  3. Open hinged control panel doors; connect lead from terminal 63 to correct terminal (H2, H3, H4, H5 or H6).
  4. Close front panel and secure with 1/4 turn fasteners.
  5. Connect load wires to generator leads.
Battery Electrolyte Dilution for Hot Locations maintenance

⚠ Avoid skin or clothing contact with the electrolyte.

Tools: Hydrometer

  1. Fully charge the battery.
  2. With battery still on charge, draw off electrolyte above the plates in each cell; do not pour off.
  3. Refill each cell with distilled water to normal level.
  4. Continue charging for 1 hour at a 4 to 6 hour rate.
  5. Test each cell; repeat until specific gravity reduced to 1.225.
Coolant Filter (Corrosion Resistor) Element Change maintenance

⚠ Do not use antifreeze with an anti-leak formula; stop-leak element can prevent or retard flow through the filter.

  1. Clean filter body and surrounding area; close coolant inlet and outlet shutoff valves.
  2. Remove drain plug from bottom of filter body and drain coolant.
  3. Remove capscrews attaching filter cover; remove cover.
  4. Lift upper plate and filter element out; discard filter element.
  5. Remove lower corrosion resistor plate and spring; inspect and clean plate, replace if thin, pliable or holed.
  6. Remove and clean sump plate; clean sump area.
  7. Install sump plate, spring, lower corrosion resistor plate, and new filter element.
  8. Install cover with gasket; replace drain plug and open shutoff valves.
Out-of-Service Protection (over 30 days) maintenance
  1. Check coolant, top up if necessary using recommended anti-freeze.
  2. Run set until thoroughly warm; generator under at least 50% load.
  3. Shut down engine and drain oil base while still warm; refill and attach warning tag indicating oil viscosity.
  4. Service air cleaner.
  5. Clean throttle and governor linkage and protect by wrapping with a clean cloth.
  6. Plug exhaust outlets to prevent entrance of moisture, bugs, dirt.
  7. Clean off dirt and dry entire unit; coat parts likely to rust with light grease or oil.
  8. Disconnect battery and follow standard battery storage procedure; apply non-conductive grease to cable lugs.
Priming Fuel System maintenance

⚠ Do not smoke while handling fuel. Diesel fuel is flammable.

Tools: Wrench, Torque wrench

  1. Open bleed screw on inlet side of fuel filter.
  2. Actuate priming lever on fuel transfer pump until bubble-free fuel flows.
  3. Close filter inlet bleed screw.
  4. Open bleed screw on outlet side of filter.
  5. Actuate priming lever until bubble-free flow; close outlet bleed screw.
  6. Open one or two bleed screws on fuel injection pump.
  7. Actuate priming lever until bubble-free fuel is emitted; close bleed screw(s).
  8. Torque all bleed screws (Filter 5-7 lb-ft; Pump 3-5 lb-ft).
Returning a Unit to Service maintenance

⚠ Do not smoke while servicing batteries. Explosive gases are emitted from batteries in operation.

Tools: Hydrometer

  1. Remove cover and protective wrapping; remove plug from exhaust outlet.
  2. Check warning tag on oil base; verify oil viscosity correct for ambient temperature.
  3. Clean and check battery; measure specific gravity (1.260 at 77 F [25 C]) and verify level at split ring.
  4. Check coolant level, adjust if necessary.
  5. Connect batteries.
  6. Verify that no loads are connected to generator.
  7. Start engine.
  8. After start, apply load to at least 50 percent of rated capacity; check all gauges.
Starting the Set operation
  1. Verify crankcase filled, cooling system filled and input solenoid valve open.
  2. Verify batteries charged and connected and fuel solenoid valve open.
  3. Move the run-stop/reset-remote switch to the run position.
  4. Observe oil pressure gauge (normal 30 to 55 psi).
  5. Check DC ammeter (10 to 30 amperes), AC voltmeter and frequency meter.
Stopping the Set operation
  1. Run the engine at no load for three to five minutes to reduce and stabilize engine temperatures.
  2. Move the run-stop/reset-remote switch to stop position to shut down the set.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

VoltagePhaseConnectionLeadsNotes
110/1903Series Delta12-lead (T1-T12); reference wire W12 to H350 Hz; 142 amperes
115/2003Series Delta12-lead (T1-T12); reference wire W12 to H450 Hz; 135 amperes
115/2301Double Delta12-lead (T1-T12); reference wire W12 to H650 Hz; 78 amperes
115/2301Not reconnectible (Code 3)3-lead (T0, T1, T2)50 Hz; 204 amperes; factory connection
115/2303Parallel Delta12-lead (T1-T12); reference wire W12 to H650 Hz; 118 amperes
120/2083Series Delta12-lead (T1-T12); reference wire W12 to H360 Hz; 156 amperes
120/2401Double Delta12-lead (T1-T12); reference wire W12 to H560 Hz; 90 amperes
120/2401Not reconnectible (Code 3)3-lead (T0, T1, T2)60 Hz; 234 amperes; factory connection
120/2403Parallel Delta12-lead (T1-T12); reference wire W12 to H560 Hz; 135 amperes
127/2203Series Delta12-lead (T1-T12); reference wire W12 to H460 Hz; 148 amperes
139/2403Series Delta12-lead (T1-T12); reference wire W12 to H560 Hz; 135 amperes
220/3803Wye12-lead (T1-T12); reference wire W12 to H350 Hz; 71 amperes
230/4003Wye12-lead (T1-T12); reference wire W12 to H450 Hz; 68 amperes
240/4163Wye12-lead (T1-T12); reference wire W12 to H360 Hz; 78 amperes
254/4403Wye12-lead (T1-T12); reference wire W12 to H460 Hz; 74 amperes
277/4803Wye12-lead (T1-T12); reference wire W12 to H560 Hz; 68 amperes
347/6003Wye12-lead (T1-T12); reference wire W12 to H560 Hz; 54 amperes; 9XR; H3 not reconnectible

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Common questions

What size generator is the Cummins/Onan 45.0 DEF-3R?

The Cummins/Onan 45.0 DEF-3R is rated 45 kW standby (56.25 kVA).

Which engine powers the Cummins/Onan 45.0 DEF-3R?

The Cummins/Onan 45.0 DEF-3R is powered by the Ford 2713E engine.

What kind of fuel does the Cummins/Onan 45.0 DEF-3R run on?

The Cummins/Onan 45.0 DEF-3R runs on diesel.

What is the oil capacity of the Cummins/Onan 45.0 DEF-3R?

The Ford 2713E engine in the Cummins/Onan 45.0 DEF-3R has an oil capacity of 13.25 liters.

What alternator comes on the Cummins/Onan 45.0 DEF-3R?

The Cummins/Onan 45.0 DEF-3R uses a UR (3-lead) alternator.

What air filter fits the Cummins/Onan 45.0 DEF-3R?

The Cummins/Onan 45.0 DEF-3R uses air filter part number 140-1089.

Troubleshooting

6

Symptoms & remedies

SymptomRemedy
Engine stops cranking and fault lamp lights, after cranking approximately 75 seconds.See engine service manual for troubleshooting fuel system. After correcting problem, reset engine monitor relay by placing Run-Stop/Reset-Remote switch to Stop/Reset position, then back to the required running position.
Fault lamp lights immediately after engine starts.Check for: Overspeed condition as engine starts.
Fault lamp lights and engine shuts down after running for a period.Check the following: a. Oil level. Engine will shut down if sensor is closed. b. Check engine manual for troubleshooting oil system. c. High engine temperature. Check coolant level; check water flow (city water cooled systems); check radiator for free air flow, and fan belts for tightness. See engine manual for troubleshooting cooling system. d. Check for faulty oil pressure sensor or faulty high engine temperature sensor.
Engine runs, shuts down and cranks for 75-seconds. Cranking cycle stops; fault lamp lights.Check fuel supply.
Fault lamp lights, no fault exists.To check a no-fault condition, disconnect leads from TB11 terminals 29, 30 and 31. If fault lamp lights with leads disconnected, replace engine monitor board. Reconnect leads.
Overcrank fault lamp lights and engine stops cranking after approximately 75-seconds.See engine service manual for troubleshooting fuel system. After correcting fault, reset engine monitor relay by placing Run-Stop/Reset-Remote switch to Stop/Reset position, depressing Reset button, then to the required running position.

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan 45.0 DEF-3R troubleshooting guide (13 entries) →

Parts

52model family
Part #DescriptionQtySystem
102-0532Gasket, Oil Drain1Gasket Amazon eBay
130-0497Filter, Water - Complete (Cooling System Filter, Optional)1Coolant filter Amazon eBay
130-0771Element Replacement Kit, Water Filter - Chromate Element (Original Equipment)1Coolant filter Amazon eBay
130-0772Element Replacement Kit, Water Filter - All Purpose, Year Around Element1Coolant filter Amazon eBay
130-0775Element, Filter - Chromate Element (Regular Formula)1Coolant filter Amazon eBay
130-0776Element, Filter - All Purpose, Year Around1Coolant filter Amazon eBay
130-0778Gasket, Cover (Water Filter)1Gasket Amazon eBay
130-1016Gasket, Water Outlet (Begin Spec H)1Gasket eBay
140-1089Element, Air Cleaner1Air filter Amazon eBay
140-1091Cleaner, Air (Includes Element)1Air filter Amazon eBay
150-0638Joint, Rod to Injection Pump1Fuel pump Amazon eBay
191-0732Regulator, Voltage (Part of Alternator)1Avr Amazon eBay
193-0104Sender, Water Temperature Gauge1Sensor Amazon eBay
193-0108Sender, Oil Pressure Gauge1Sensor Amazon eBay $119.99
193-0202Sender, Oil Temperature - Optional1Sensor Amazon eBay
212-0342Rig Assembly, Brush - Includes Brushes and Springs (Early Brush Type Generators)1Brush eBay
214-0046Brush (Early Brush Type Generator)4Brush Amazon eBay
305-0489REGuLATOR, VOLTAGE (All Parts Common Exc~pt As1Avr Amazon eBay
309-00641 Spec A through F1Sensor Amazon eBay
309-0106Switch, Thermostat (Water Jacket Heater, 120 Volt)1Thermostat eBay
309-0178'Switch, Thermostatic - Hi Engine Coolant Temperature1Sensor Amazon eBay $350.00
309-0179'Switch, Thermostatic - Hi Engine Coolant Temperature1Sensor Amazon eBay
309-0256Thermostat (240 volt water jacket heater)1Thermostat eBay
309-0269Switch, Low Engine Temperature (S4)1Sensor Amazon eBay
315-0341Reactor Assembly, Commutator - Brush Type Generator1Avr eBay
315-0343Reactor Assembly, Commutator - Brushless Generator1Avr Amazon eBay
358-0029Rectifier, Silicon (CR5) - Brushless Generator1Avr eBay
358-0031Rectifier, Silicon (CR1 & CR2) - Brush Type Generator2Avr eBay
358-0035Rectifier, Silicon (CR1 & CR2) - Brushless Generator2Avr eBay
503-0441Hose, Radiator1Hose Amazon eBay
503-0597Hose, Air Cleaner1Hose Amazon eBay
509-0125Seal, 011- 'O' Ring1Seal Amazon eBay
511-0084Belt, Charging Alternator1Belt Amazon eBay
130-0780Plate, Sacrificial (Water Filter)1Service part / kit Amazon eBay
204-0083Ring, Collector (Early Brush Type Generator)1Service part / kit eBay
212-1105AC Brush Spring and Support (One for Each AC Brush)4Service part / kit Amazon eBay
300-0679Part 300-06791Service part / kit Amazon eBay $497.00
300-0681Monitor, Engine Control - 12 Volt (Sets With Five Fault Lights - Optional)1Service part / kit Amazon eBay
300-0714Control, Cranker Cycle - 12 Volt1Service part / kit Amazon eBay
300-0730Standard Engine Control Monitor1Service part / kit Amazon eBay
300-0733Standard Cranker (12 VDCj 300-0714 1 Cycle Cranker (12 VDC)1Service part / kit Amazon eBay
305-0491REGULATOR. 305-04911Service part / kit Amazon eBay
306-0161Spring, Plunger (Stop Solenoid)1Service part / kit eBay
306-0222Plunger, Stop Solenoid1Service part / kit eBay
307-0628Solenoid, Stop (12 Volt)1Service part / kit Amazon eBay FridayParts $94.00
309-01691 Begin Spec G 25 261Service part / kit Amazon eBay
333-0052Heater, 1500 Watt (120 volt water jacket heater)1Service part / kit eBay
333-0073Heater, 2000 Watt (240 volt water jacket heater)1Service part / kit eBay
358-0015Diode, Negative (Part of Exciter Rotor)3Service part / kit Amazon eBay
358-0016Diode, Positive (Part of Exciter Rotor)3Service part / kit Amazon eBay
504-0030Valve, Oil Drain1Service part / kit Amazon eBay
510-0101Bearing (Generator)1Service part / kit Amazon eBay

Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Fuel consumption

RatingLoadL/hgal/h
Continuous100%13.33.5

Available documents

Operator's manual — 977-0307 Onan DEF Operator's and Parts Manual (12-1976) (Onan (Onan Corporation, a Division of Onan))