Cummins/Onan MCGCB Generator Set

1. Warm up the set under partial load (at least 1/4 rated load).
2. Turn the Speed potentiometer to obtain specified frequency (60 Hertz - 1800 RPM or 50 Hertz - 1500 RPM).
3. Turn the Gain potentiometer clockwise until the governor begins to hunt, then turn it back until there is no audible hunting.
4. Connect 1/4 rated load and readjust the Gain potentiometer if necessary.
5. Connect rated load in one step; shut down the set if it cannot pick up the load, lengthen the governor rod by half turns of the swivel ends and repeat until it picks up rated load.
6. Back off the governor full speed stop screw if necessary.
7. Check for stability (no audible hunting) under various loads.
8. Stop the set and wait 30 seconds for the turbo to coast down, restart and check for speed overshoot; check for binding in the governor rod if overspeed shutdown occurs.

1. Adjust output voltage plus or minus five percent of nominal using the adjustment screw on the back of the power supply outlet box.
2. Call your distributor if the required voltage cannot be obtained by this adjustment.

⚠ Accidental starting can cause severe personal injury or death. Disconnect the starting battery cables (negative (-) first).

⚠ Do not smoke near batteries.

1. Connect two 12 volt batteries in series to obtain 24 volts.
2. Secure the negative battery cable to the starter or to the engine block.
3. Remove paint, rust or grease under the connector so that it touches bare metal.
4. As the last step, connect the negative (-) battery cable to the engine.

1. Bar the engine until a gear tooth on the flywheel lines up in the center of the mounting hole.
2. Thread the sensor in gently by hand until it just touches the gear tooth.
3. Back it out one quarter turn and set the lock nut.

⚠ Diesel fuel is highly combustible.

1. Loosen the fuel line fitting at the filter head.
2. Pump the priming lever on the fuel lift pump until fuel starts flowing from the fitting and is free of air.

⚠ Used engine oils have been identified by some state or federal agencies as causing cancer or reproductive toxicity; avoid ingesting, breathing fumes or contact.

Tools: filter wrench

1. Run the engine until it is up to operating temperature and shut it off.
2. Open the oil drain valve and drain the oil into a suitable container.
3. Remove the oil filter with a filter wrench.
4. Fill the new filter with oil and apply a film of oil to the gasket.
5. Screw the filter on by hand until the gasket just touches the filter head, then tighten another 3/4 turn.
6. Close the oil drain valve and fill with oil to the high mark (H) on the dipstick.
7. Start the engine and check for leaks.
8. Shut off the engine, wait 10 minutes and refill to the high mark (H) if necessary.

⚠ To prevent severe scalding, always let the engine cool down before removing the coolant pressure cap; turn the cap slowly and do not open it fully until pressure is relieved.

⚠ The sea water pump impeller can disintegrate if pump prime has been lost.

1. Prime the sea water pump by disconnecting the pump outlet hose and pouring water into the pump outlet; reconnect hose and open sea cock (heat exchanger cooled sets).
2. Fill coolant until the expansion tank is approximately half full; bleed air from any air vents while filling.
3. Run the engine while watching the coolant level; add coolant as necessary so the expansion tank is full at normal operating temperature.
4. Secure the pressure cap.

⚠ Diesel fuel is highly combustible. Do not smoke near fuel tanks and fuel lines; keep flames and ignition sources away.

1. Fill the replacement fuel filters with fuel and apply a film of fuel to the gasket.
2. Screw the filter on by hand until the gasket just touches the filter head.
3. Tighten the filter another 3/4 turn.

1. Remove the end cap and drain plug to clean the sea water side of the heat exchanger.
2. Follow the instructions in the engine Operation Manual for cleaning the heat exchanger.
3. Take the heat exchanger to a radiator shop if it is badly fouled.
4. Remove the end cap to remove impeller debris if the sea water pump impeller disintegrates.
5. Replace the drain plug if the zinc anode is more than half consumed.

1. Disconnect the oil supply line at the turbocharger housing.
2. Fill the bearing with engine oil.
3. Reconnect the oil line.

⚠ Failure to provide an approved fuel/water separator and filter upstream of the engine-mounted fuel lift pump can lead to pump and injection unit failures.

⚠ Let the engine cool down before removing the coolant pressure cap; turn the cap slowly.

⚠ The sea water pump has a neoprene impeller that can disintegrate in seconds if pump prime has been lost.

1. Check that an approved fuel/water separator is installed upstream of the engine-mounted fuel lift pump.
2. Check the fuel supply and prime the engine fuel system if necessary.
3. Check engine oil and coolant levels before starting the set.
4. Make sure the sea water cock is open on a heat exchanger-cooled set; prime the sea water pump if prime is lost.

⚠ Excessive cranking can overheat the starter motor and cause it to fail. Do not crank the engine for more than 30 seconds at a time. Wait two minutes before trying again.

1. Hold the control panel switch in the START position.
2. Release the switch when the engine starts.
3. The starter will disengage automatically when the engine starts up.