Generac MMG50ITM Generator Set

1. Press and hold ENTER, then press the up or down arrow to increase or decrease brightness.
2. Release ENTER when the desired brightness is attained.

⚠ NEVER change the voltage selector switch while the engine is running or the controller is on.

Tools: Flat head screwdriver

1. Check the output voltage on the Generator screen (L1N or L12 voltage).
2. Nominal output voltage should be within 10% of the voltage rating on the voltage selector switch.
3. Use a flat head screwdriver to turn the voltage adjustment screw until the voltage matches the selector setting.
4. Adjustment must be made within the 45 second V Detect countdown.

⚠ If the jack was used to support the unit, move the jack back to the tongue location before towing.

Tools: Hoist or forklift, Front jack, Hitch pins

1. Elevate the unit using a hoist or forklift, or use the front jack on the trailer tongue.
2. Remove the hitch pin (1) securing the tongue to the trailer frame, then remove hitch pin (2) from the trailer frame.
3. Lower the trailer tongue and reinstall the hitch pins at the locations shown (3).

Tools: Torque wrench

1. Disconnect the engine starting battery.
2. Remove the generator fan guard.
3. Torque each of the drive plate bolts to 36 ft-lbs (49 Nm).
4. Reinstall the generator fan guard. Reconnect the battery.

⚠ Perform these procedures at least annually.

Tools: Grease gun or needle nose applicator, Automotive grease, Lightweight oil

1. Side-wind models: apply a small amount of automotive grease to the internal gearing via the jack cover or lubrication point.
2. Side-wind models: apply lightweight oil to the handle unit at both sides of the tube.
3. Side-wind models: lubricate the caster wheel axle bolt and nut assembly with the same lightweight oil.
4. Top-wind models: apply a lightweight oil to the screw stem.

1. With the unit shut down, power up the controller with the Control Power switch.
2. Press PAGE SELECT; lines of text display starting with Password.
3. Press the down arrow to move the cursor to Engine Protect.
4. Press ENTER; WrnMaintenance appears with the current service time (0) below it.
5. Press ENTER; the current run time in hours appears under WrnMaintenance.
6. Press the up arrow to reset the current run time hour setting to 250.
7. Press ENTER to save the run time hour setting.
8. Move the Control Power switch to the OFF (O) position.

⚠ Use only a high quality grease made specifically for lubrication of wheel bearings.

Tools: Standard grease gun

1. Remove the small rubber plug on the grease cap.
2. Attach a standard grease gun fitting to the grease zerk fitting and pump grease until new grease is visible around the nozzle.
3. Wipe any excess grease from the hub with a clean cloth and replace the rubber plug.

⚠ Verify that the contacts on any remote switch linked to the unit are OPEN before entering Auto mode.

Tools: Jumper wire (minimum 16 gauge)

1. Perform a manual start of the generator at least once to verify the engine operates correctly.
2. To check the remote start circuit, remove the remote start terminal block wires, press Auto, and attach a jumper wire (minimum 16 gauge) across the two terminals.
3. The engine should crank, start and run.
4. Remove the jumper wire; the engine stops. Reconnect any necessary remote start switch wires.
5. Confirm the unit is in Auto mode; the LCD window should have AUT highlighted.
6. Close the main circuit breaker (set to ON (I) position).
7. Secure the generator by closing and locking all access doors.

⚠ The controller must be in Auto mode to run at the programmed time. Use a trickle battery charger or solargizer to prevent the controller from draining the battery while in Auto mode.

1. Press PAGE SELECT until Password appears at the top of the screen.
2. Press down arrow until Date/Time is selected and press ENTER.
3. Press down arrow until Timer1 Repeat is selected and press ENTER.
4. Choose the day or days the unit should run and press ENTER.
5. Press down arrow until Timer1 ON Time is selected and press ENTER.
6. Adjust the desired time to start running and press ENTER.
7. Press down arrow until Timer1Duration is selected and press ENTER.
8. Adjust the run period length and press ENTER.
9. Press PAGE SELECT three times to return to the Main menu.
10. Press AUTO to switch modes to automatic.

⚠ CARBON MONOXIDE: USING A GENERATOR INDOORS CAN KILL YOU IN MINUTES.

1. Move the Control Power switch to the ON (I) position.
2. The LCD window displays system information and all LEDs flash.
3. The Ready screen is displayed and the LCD indicates Manual mode; Ready/Manual LED lit.
4. Press ENGINE START. The Prestart screen is displayed and a countdown begins from 20 seconds to 0.
5. The Starting screen is displayed. The engine cranks and starts running.
6. The Running screen displays. The 45 second V Detect time delay begins counting down.
7. The LCD window toggles from the Running screen to the Generator screen then the Engine screen.
8. If the engine does not start, it pauses 15 seconds; up to three crank cycles are made.
9. If the engine does not start, LCD shows SD START FAIL. Press FAULT RESET to clear the controller.
10. Once started, the engine speeds up to a constant 1800 rpm.
11. Check for excessive noise, vibration, and coolant, oil or fuel leaks before applying loads.
12. Check that the AC output voltage is correct; fine adjust with the fine voltage adjustment screw.
13. Check that the frequency is correct; with no loads it should read approximately 60 Hz.
14. Switch the main circuit breaker to ON (I), then add convenience receptacle loads via their breakers.

⚠ If the unit does not shut down within 15 seconds, a stop fail alarm will be displayed.

1. Remove all loads from the generator by opening all circuit breakers (turn to OFF (O) position).
2. Let the engine run for approximately five minutes to allow it to cool down.
3. Push ENGINE STOP. A 15 second shutdown timer (stop value) starts.
4. Move the Control Power switch to the OFF (O) position.

⚠ NEVER tow trailer using defective parts!

Tools: Jack, Torque wrench

1. Use the jack to raise or lower the trailer onto the hitch of the towing vehicle; lock the coupling and attach safety chains.
2. Connect trailer wiring to the tow vehicle and check directional and brake lights.
3. Make sure all doors are closed and secure.
4. Check for proper inflation of the trailer tires.
5. Check the wheel lugs; tighten to 20-25, 50-60, then 90-120 ft-lbs in sequence.
6. Maximum recommended highway towing speed is 45 mph (72 km/h); off-road not to exceed 10 mph (16 km/h).