Cummins/Onan 40.0 DEF-3R50 Generator Set

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.

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.

⚠ 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.

⚠ 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.

⚠ 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.

⚠ 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.

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.

⚠ 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).

⚠ 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.

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.

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.