Caterpillar 3516C Engine

⚠ Loose belts reduce efficiency; too tight belts reduce service life

1. Remove the drive belt guard.
2. Loosen mounting bolt (1), adjusting nuts (2) and mounting bolt (3).
3. Turn adjusting nuts (2) to increase or decrease drive belt tension.
4. Tighten adjusting nuts (2), mounting bolt (3) and mounting bolt (1) to proper torque.
5. Reinstall the drive belt guard.
6. Check drive belt tension again after 30 minutes at rated rpm for new belts.

⚠ Do not start the engine during the test

⚠ Use EMERGENCY STOP switch to stop engine if it does not shut down

1. Ensure both air shutoff gates latched OPEN and switches connected; turn power ON.
2. Activate EMERGENCY STOP switch; both gates should close.
3. Reset EMERGENCY STOP to RUN; reset right side air shutoff OPEN.
4. Select Run/Start; engine should fail to start.
5. Reset EMERGENCY STOP; reset left side air shutoff OPEN; engine should fail to start.
6. Start engine; disconnect right side air shutoff; gates should close and engine shut down.
7. Start engine; disconnect left side air shutoff; gates should close and engine shut down.
8. Reset both air shutoffs and EMERGENCY STOP switch; operate engine normally.

⚠ Do not operate the generator set at a speed higher than one-half of rated speed

Tools: 237-5130 Digital Multimeter, 12 VDC Battery, Potential Transformer

1. Stop generator; connect potential transformer to terminals T1 and T2; connect voltmeter to low voltage winding.
2. Disconnect wires F1+ and F2- from the voltage regulator; disconnect generator from load.
3. Connect a 12 VDC automotive battery to wires F1+ and F2-.
4. Operate generator set at half the rated speed.
5. Measure AC voltage across low voltage terminals for T1-T2, T2-T3, and T3-T1; record.
6. Decrease generator set speed by 10 percent; increase by 10 percent.
7. Voltages measured should be nearly equal and minimum of 85 VAC.
8. Voltages should change 10 percent with the 10 percent speed change.

⚠ High voltage produced by operating generator set can cause severe injury or death

⚠ Do not touch instrument leads without first discharging them

Tools: 300-8648 Insulation Testing Gp

1. Take generator out of service.
2. Visually inspect for moisture; if moisture exists, dry unit first.
3. Inspect installation; determine equipment to test.
4. Discharge capacitance of windings.
5. Disconnect T0 from ground.
6. Disconnect sensing lead wires for the regulator.
7. Disconnect PT leads of load share module.
8. Connect black lead to ground and RED lead to T0.

⚠ Replace any faulty rectifiers with rectifiers that have comparable operating characteristics

Tools: 237-5130 Digital Multimeter, 257-9140 Multimeter, 146-4080 Digital Multimeter (RS-232), 7X-1710 Multimeter Probe Group

1. Remove the cover from the exciter.
2. Remove the nut that secures the rectifier to the heat sink.
3. Remove the diode lead.
4. Lift the rectifier from the heat sink.
5. Connect ohmmeter leads across the rectifier; note reading.
6. Reverse the ohmmeter leads; note reading.
7. Low resistance one direction and high resistance reversed indicates good rectifier.
8. Low resistance both directions is shorted; high resistance both directions is open.

⚠ Do not disconnect or remove hoses or fittings until all pressure in the system has been relieved

⚠ Contain fluids and dispose of according to local regulations

1. Ensure air supply to lubricator is OFF.
2. Slowly loosen filler plug to release pressure from lubricator.
3. Place container under bowl and open drain valve to drain oil.
4. Remove bowl; clean with warm water.
5. Dry bowl; inspect for cracks; replace if cracked; inspect gasket.
6. Install bowl.
7. Make sure drain valve is closed.

⚠ All lead-acid batteries contain sulfuric acid which can burn skin and clothing

⚠ Wear a face shield and protective clothing

Tools: 245-5829 Coolant Battery Tester Refractometer, 5N-5561 Silicone Lubricant

1. Remove filler caps; maintain electrolyte to FULL mark; use distilled water if needed.
2. Check electrolyte condition with 245-5829 Coolant Battery Tester Refractometer.
3. Keep batteries clean; clean case with baking soda/water or ammonia/water solution.
4. Rinse case with clean water.
5. Clean terminals and cable clamps with fine sandpaper until bright.
6. Coat clamps and terminals with 5N-5561 Silicone Lubricant, petroleum jelly or MPGM.

⚠ Hot oil and hot components can cause personal injury

⚠ Do not drain the oil when the engine is cold

⚠ Personal injury can result from parts and/or covers under spring pressure

Tools: Absorbent towels or pillows

1. Operate engine at normal operating temperature, then STOP the engine.
2. Drain the oil according to the equipment on the engine.
3. Replace the engine oil filter elements before filling the crankcase.
4. Remove cover, spring, O-ring seal, retainer and oil filter elements.
5. Clean cover, spring, O-ring seal, retainer and inside of oil filter housing.
6. Install new oil filter elements; install new O-ring seal if damaged.
7. Install retainer, spring and cover.
8. Fill crankcase; start engine and check for oil leaks.

⚠ Fuel leaked or spilled onto hot surfaces or electrical components can cause a fire

⚠ Personal injury can result from parts and/or covers under spring pressure

1. Stop the engine; ensure engine will not start.
2. Shut off the fuel supply valve to the engine.
3. Connect a hose to drain; open drain valve; remove plug; allow fuel to drain.
4. Gradually loosen bolts; pry cover loose to relieve spring pressure; remove cover and elements.
5. Clean cover, O-ring seal and inside of fuel filter housing.
6. Install new fuel filter elements.
7. Inspect O-ring seal; install new seal if damaged.
8. Install cover ensuring springs are seated; open fuel supply valve; prime fuel system.

⚠ Do not operate generator if windings are wet

⚠ Only qualified personnel should perform troubleshooting and repair

Tools: 225-8266 Clamp-on ammeter (1200 amperes), External power source circuit

1. Make external power source per Illustration 91.
2. Disconnect F1+ and F2- from voltage regulator; connect generator output leads T0, T1, T2, T3 together; install clamp-on ammeter on T1.
3. Adjust rheostat to maximum resistance; connect external power source to F1+ and F2-.
4. Start generator set; run at idle speed.
5. Monitor phase current; gradually increase engine rpm with EMCP 3 control panel.
6. Slowly turn rheostat until rated phase current is reached.
7. Stop hourly; check insulation resistance; repeat until acceptable.

⚠ Do not mix greases

Tools: Grease fitting

1. Remove louver assembly or rear plate from rear of generator housing.
2. Remove the top grease pipe plug and the lower grease pipe plug.
3. Install a grease fitting in the grease pipe.
4. Grease the bearings with the appropriate grease from Table 24; do not mix greases.
5. Wipe off excess grease; remove top grease fitting; install plug.
6. Operate generator for one hour to allow grease to expand and purge.
7. Stop engine; install plug in bottom grease pipe; wipe off excess grease.
8. Install the louver assembly or rear plate.

⚠ Ensure engine will not start during priming

1. Open the fuel supply valve; turn start switch OFF.
2. Turn fuel priming pump plunger counterclockwise to release lock plate.
3. Operate fuel priming pump until air is pumped through return line to tank.
4. Push plunger to locking position; turn clockwise to engage lock plate.
5. Enable starting system only after all maintenance is completed.