Mga Pamamaraan sa Pagpapanatili ng Diesel Generator Set

1. Preface

In order to enhance the management of production equipment, modernize equipment management, and ensure timely repair, modification, and replacement, this document has been prepared. Its purpose is to ensure proper use, meticulous maintenance, and scientific inspection of equipment so that all machinery remains in optimal technical condition. By continually improving technical standards and reducing consumption while ensuring safe production, the overall economic benefits can be increased.

2. Technical Specifications

2.1 Diesel Generator Set Specifications

2.2 Protection Systems

The diesel generator set is equipped with multiple protection devices:

• Generator Protection (provided by Voltage Regulator DVR):

  • Overvoltage protection (trips when voltage exceeds limits)

  • Undervoltage protection

  • Low-frequency protection

  • Internal fault protection (short-circuit and overcurrent signal tripping)

  • Field excitation failure

  • Overload of the excitation system (trips after 15 seconds)

  • Faults in the rotating diodes (short or open circuit)

• Diesel Engine Protection (provided by the EMCPⅡ control system):

  • High coolant temperature protection (shutdown if >107 °C)

  • Warnings for abnormal coolant temperature

  • High oil temperature protection (shutdown)

  • Overspeed protection (shutdown if speed exceeds 2120 rpm)

  • Backup fault shutdown and alarm functions

  • Battery charger and low battery voltage indications

  • Emergency stop button function

3. Inspection and Maintenance

3.1 Pre-Operation Checks

Before starting the generator, ensure the following:

• External Visual Inspection:
  Check for physical damage, missing components, loose fasteners, and any signs of cable or connector damage.

• Fuel System:
  Verify fuel levels and inspect hoses and fittings for leaks or looseness. Bleed any air from the system.

• Lubrication System:
  Confirm that engine oil levels are adequate.

• Cooling System:
  Ensure the coolant level in the radiator is sufficient; add anti-rust agent if needed.

• Battery System:
  Check electrolyte levels, verify correct voltage, inspect terminal connections, and confirm charger operation.

• Exhaust System:
  Examine the muffler for damage and secure mounting of exhaust pipes.

• Site Safety:
  Ensure that no flammable materials or debris are stored near the unit, and that the generator room is well ventilated.

• Operational Protocol:
  Start the generator once per month to verify proper operation. Unauthorized personnel should not enter the generator room.

3.2 Starting and Stopping Procedures

• Manual Test Run:

  • Perform a no-load test run for 10–15 minutes once a month.

  • Verify the alarm system is functioning by switching the control to the manual (MAN) mode.

  • To stop the generator, switch the control to STOP or press the red emergency stop button. (Note: After an emergency stop, the button must be reset before restarting.)

3.3 Monitoring During Operation

During operation, continuously monitor the following parameters at 30-minute intervals:

• AC Current and Voltage:
  Verify that the current readings on all phases are balanced (ideally within a 5% difference) and that voltage levels remain within specified limits.

• Oil Pressure and Temperature:
  Oil pressure should typically range between 350–600 kPa (not below 300 kPa). Oil temperature should stabilize between 60–150 °C after one hour at full load.

• Coolant Temperature:
  Normal operating range is approximately 70–95 °C.

• Auditory and Vibration Checks:
  Listen for any abnormal noises or vibrations that might indicate mechanical issues.

3.4 Post-Operation Checks

After shutdown, conduct the following inspections:

• Check the crankcase oil level.

• Verify fuel tank levels and replenish if necessary.

• Record the charging current of the battery charger.

• Log the operating hours.

• Document any faults and perform a comprehensive inspection.

• Ensure that the automatic shutdown mode is activated by switching the control to AUTO.

4. Scheduled Maintenance and Lubrication Standards

4.1 Maintenance Levels and Intervals

Preventive maintenance is divided into five levels to ensure safe operation until the next scheduled maintenance. Adjustments to these intervals may be made based on actual operating conditions.

• W1 – Daily/Run Checks:

  • In standby mode: daily checks

  • In operation: every 30 minutes, including a visual and parameter check

• W2 – Periodic Maintenance:

  • Interval: every 250 operating hours

  • Tasks include: replacing fuel and oil filters, cleaning air filters, checking the excitation gap (0.75–1.00 mm), lubricating bearings, and inspecting coolant levels.

• W3 – Regular Maintenance:

  • Interval: every 500 operating hours

  • Tasks include: replacing fuel filters, oil separators, air filters, and engine oil, plus similar checks as W2.

• W4 – Intermediate Overhaul:

  • Interval: every 5000 operating hours

  • Tasks include: replacing connecting rod and piston rings, measuring cylinder wall clearance, checking valve clearance, grinding valves, and reassembling the repair package. Bolt tightening intervals for engine moving parts are calculated based on usage.

• W5 – Major Overhaul:

  • Interval: every 10,000 operating hours

  • Involves complete disassembly, replacement of main components (main bearing shells, connecting rod bearings, complete repair packages, etc.), cleaning oil passages, and rechecking valve timing and injection.

4.2 Lubrication Standards

For the Perkins diesel generator set:

• Lubrication Area:
  The engine’s internal components.

• Lubricant Specification:
  10W-40 oil (Mobil or Shell recommended).

• Method of Oil Injection:
  Using an oil pump.

• Oil Change Interval:
  Every 500 operating hours, with 180 L used initially or at each change. Approximately 10 kg of oil may be added as needed.

• External Bearings:
  Use standard Mobil grease.

5. Maintenance Technical Standards

This section defines the inspection methods, measurement criteria, and repair standards for key engine components. (The following is an abbreviated summary; refer to detailed engineering drawings and standards for full tolerances.)

5.1 Key Component Inspection Criteria

• Crankshaft and Connecting Rods:

  • Use dial gauges to measure journal diameters and clearances.

  • Replace components if measurements fall outside specified limits (e.g., main journal diameters should be within 120.59–120.57 mm with a roundness tolerance of 0.05–0.10 mm).

• Piston, Piston Pin, and Rings:

  • Measure dimensions with micrometers and feeler gauges.

  • Inspect ring gaps and replace if outside the standard ranges (e.g., piston ring gap for the first ring should be 0.25–0.45 mm).

• Valve and Camshaft Assemblies:

  • Check valve stem diameters, guide clearances, and spring lengths.

  • Measure camshaft dimensions and ensure the lobes are within tolerance.

• Fastening and Torque Settings:

  • Use calibrated torque wrenches to tighten bolts to specified values (e.g., cylinder head bolts at 60–80 Nm, main bearing cap bolts at 177–196 Nm).

  • Follow a prescribed tightening sequence to ensure even load distribution.

5.2 Inspection Methods

• Dial Gauge and Micrometer Measurements:
  For precision dimensions of journals, pins, and clearances.

• Feeler Gauge Measurements:
  For determining gap tolerances in piston rings and valve clearances.

• Torque Wrench Verification:
  For ensuring proper bolt tightening in assembly.

6. Troubleshooting and Abnormal Operation

The generator set may experience various abnormal conditions. Below is a summary of common issues and the corresponding troubleshooting steps.

6.1 Engine Starting Issues

• Symptoms:
  Difficulty or inability to start.

• Possible Causes and Remedies:

  • Battery Issues: Charge or replace battery; check terminal connections.

  • Fuel System Air or Water: Bleed air from lines; clean fuel tank and lines; change diesel if contaminated.

  • Faulty Starter Motor: Repair or replace the starter.

  • Injector Problems: Clean, adjust, or replace injectors as needed.

  • Valve or Cylinder Head Leaks: Re-tighten or replace cylinder head bolts and gaskets.

6.2 Insufficient Power Output

• Possible Causes:
  Clogged fuel filters, improper injection pressure, inadequate compression, air filter blockage, or imbalance in fuel delivery.

• Remedies:
  Clean or replace filters, adjust fuel injection timing and pressure, and inspect cylinder compression.

6.3 Overspeed and Engine “Runaway” (Flyaway)

• Remedies:

  • Immediately shut down the engine if excessive oil consumption or malfunctioning governor is detected.

  • Inspect and repair the fuel injection control mechanism.

6.4 Abnormal Exhaust Smoke

• Black Smoke:
  Often due to poor atomization, incorrect injection timing, or cylinder head gasket leaks.

• Blue Smoke:
  Indicates oil burning due to worn piston rings or excessive oil levels.

• White Smoke:
  May indicate water or coolant entering the combustion chamber.

6.5 Sudden Shutdown

• Remedies:

  • Check fuel levels.

  • Inspect fuel for water contamination.

  • Examine the fuel injection pump for broken springs or damaged timing mechanisms.

  • Investigate any abnormal load conditions.

6.6 Generator Output Problems

• Symptoms:
  No power or abnormal voltage.

• Checks:

  • Verify field excitation and charging.

  • Inspect wiring and terminal connections.

  • Replace damaged rectifier diodes or brushes as necessary.

6.7 Overheating

• Symptoms:
  Elevated coolant or oil temperature.

• Causes and Remedies:

  • Unbalanced three-phase currents or blocked ventilation.

  • Check coolant level, pump performance, and clean scaling from the cooling system.

  • Verify that oil levels are within the proper range.

6.8 Engine Knocking and Abnormal Noises

• Potential Causes:
  Air in the fuel system, imbalanced fuel distribution among cylinders, improper injection timing, or excessive clearances in piston assemblies.

• Remedies:
  Adjust fuel injection timing; inspect and replace worn components (e.g., piston rings, connecting rod bushings) as necessary.

6.9 Low or No Oil Pressure

• Checks and Remedies:

  • Ensure oil level is within marks.

  • Inspect for oil leaks in pipelines.

  • Clean or replace clogged oil filters.

  • Verify the proper operation of the oil pump and gauge.

6.10 Excessive Oil Consumption

• Mga sanhi:
  Fouled or worn piston rings, blocked ring return ports, or overfilling.

• Remedies:
  Clean the piston rings; if worn beyond limits, replace them; adjust oil levels to remain within marked limits.

6.11 Insufficient Cylinder Compression

• Diagnostic Steps:

  • Measure clearance between the piston skirt and cylinder wall.

  • Inspect valve clearances and seat conditions.

  • Check piston rings and cylinder wear.

• Remedies:
  Adjust or replace components as required by the measured tolerances.

7. Engine Assembly and Major Overhaul Procedures

7.1 Assembly Procedures

• Preparation:
  All parts must be thoroughly cleaned; use compressed air to clear oil and coolant passages.

• Piston and Connecting Rod Assembly:
  Heat the piston to 80–100 °C. Ensure that the side with the intake/exhaust recess aligns correctly with the corresponding connecting rod marking.

• Piston Ring Installation:
  Use special pliers for ring installation. Note that the first and second rings have different profiles; ensure the “STD” marking on the ring is positioned as specified. Check ring gaps using a feeler gauge.

• Main Assembly:
  Install the crankshaft, connecting rods, and bearing caps in the correct order. Tighten bolts gradually in several steps, following the specified torque sequence.

• Camshaft and Valve Assembly:
  Install camshaft liners and ensure proper alignment of oil passages. Reassemble valve components and adjust clearances according to specifications.

7.2 Major Overhaul Procedures

A typical major overhaul includes the following steps:

1. Separation:
   Disconnect the engine from the generator. Drain oil, coolant, and fuel; remove external components (oil cooler, charging generator, valve assemblies, etc.).

2. Disassembly:
   Remove cylinder head covers, cylinder assemblies, camshaft end covers, fan counterweights, and other ancillary components.

3. Crankshaft and Piston Removal:
   Safely lift and secure the crankshaft; inspect journals, connecting rod bolts, and bearing surfaces.

4. Cylinder and Head Inspection:
   Measure cylinder bore and inspect for scoring or damage using magnification. Disassemble the head and injector assemblies for cleaning and inspection.

5. Reassembly:
   After cleaning and repair, reassemble engine components in reverse order of disassembly. Replace all gaskets, seals, and worn components. Ensure proper lubrication during assembly and use calibrated torque wrenches for final tightening.

6. Testing:
   Once reassembled, conduct a no-load test run to verify oil pressure, coolant flow, electrical connections, and all operating parameters before returning the unit to standby.

8. Emergency Shutdown Procedures

In the event of any of the following conditions, an immediate emergency shutdown must be executed:

• Coolant temperature exceeds 99 °C.

• A sudden, severe knocking noise or any indication of mechanical damage.

• Seizure or binding of critical engine components (cylinders, pistons, governor).

• Generator output voltage exceeds the maximum safe reading.

• Occurrence of fire, electrical leakage, or other natural hazards.

Procedure:

1. Immediately cut the load.

2. Switch the fuel injection control lever to “cut-off” to stop fuel supply.

3. Press the red emergency stop button to halt engine operation.

4. After shutdown, reset the emergency stop button by turning it counterclockwise before any restart.

This document should be used as a reference guide for qualified maintenance personnel. All measurements and torque settings must be verified with the latest manufacturer data and calibrated tools. Any discrepancies should be addressed in accordance with established engineering standards and safety protocols.