Kohler COM7.5 Service Manual
  1. Manuals
  2. Brands
  3. Kohler Manuals
  4. Portable Generator
  5. COM7.5
  6. Service manual

Kohler COM7.5 Service Manual

Commercial generator sets
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
Service
Commercial Generator Sets
Models:
COM7.5
TP-6120 5/02

Advertisement

Table of Contents
loading

Related Manuals for Kohler COM7.5

Summary of Contents for Kohler COM7.5

  • Page 1 Service Commercial Generator Sets Models: COM7.5 TP-6120 5/02...

  • Page 2: Product Identification Information

    California Proposition 65 WARNING Engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. Product Identification Information Product identification numbers determine service parts. Engine Identification Record the product identification numbers in the spaces Record the product identification information from the below immediately after unpacking the products so that engine nameplate.

  • Page 3: Table Of Contents

    Table of Contents Product Identification Information ..........Inside front cover Safety Precautions and Instructions .
  • Page 4 ............COM7.5 Disassembly .

  • Page 5: Safety Precautions And Instructions

    Safety Precautions and Instructions IMPORTANT SAFETY Accidental Starting WARNING INSTRUCTIONS. Electromechanical equipment, including generator sets WARNING and accessories, can cause bodily harm and pose life-threatening danger when improperly installed, operated, or maintained. To prevent accidents be Explosion. aware of potential dangers and act Can cause severe injury or death.
  • Page 6 Battery gases. Explosion can cause Servicing the air cleaner. A sudden Carbon monoxide symptoms. backfire can cause severe injury or Carbon monoxide can cause severe severe injury or death. Battery gases death. Do not operate the generator nausea, fainting, or death. Carbon can cause an explosion.
  • Page 7 Hazardous Noise Grounding electrical equipment. Testing live electrical circuits. Hazardous voltage cause Hazardous voltage or current can severe injury or death. Electrocution cause severe injury or death. Have CAUTION is possible whenever electricity is trained and qualified personnel take present. Open the main circuit diagnostic measurements...
  • Page 8 Moving Parts Notice NOTICE Electrostatic discharge damage. NOTICE Electrostatic discharge (ESD) WARNING damages electronic circuit boards. Hardware damage. The engine and Prevent electrostatic discharge generator set may use both American damage by wearing an approved Standard and metric hardware. Use grounding wrist strap when handling the correct size tools to prevent electronic circuit boards or integrated...

  • Page 9: Introduction

    Information in this publication represents data available and perform required service at the prescribed intervals. at the time of print. Kohler Co. reserves the right to Maintenance and service must be performed by change this publication and the products represented...

  • Page 10: Service Assistance

    Visit the Kohler Power Systems website at Phone: (86) 21 6288 0500 KohlerPowerSystems.com Fax: (86) 21 6288 0550 Look at the labels and stickers on your Kohler product India, Bangladesh, Sri Lanka or review the appropriate literature or documents India Regional Office included with the product...

  • Page 11: Section 1 Specifications

    TV systems or telecommunication sites full-wave rectifier in the control system rectifies the in place of, or in addition to, batteries. The COM7.5 is output to produce low-ripple, unfiltered DC power. available in 48 and 96 VDC models. The generator set nameplate indicates the unit’s rated voltage.
  • Page 12 12 VDC Battery ground Negative Battery recommendation (minimum) 425 CCA at --18_C (0°F) Spark plug type (Kohler Part No.) 24 132 03 (Champion RC12YC) Spark plug gap, mm (in.) 0.75 (0.030) Spark plug tightening torque, Nm (ft. lb.) 24.4--29.8 (18--22)

  • Page 13: Service Views

    6. Fuel line 16. Rectifier heat sink (hidden) 7. Dual-fuel block 17. Shipping bracket 8. Gas regulator 18. Ground connection 9. Fuel supply inlet 19. Oil pan heater 10. Oil cooler Figure 1-4 COM7.5 Service Views TP-6120 5/02 Section 1 Specifications...
  • Page 14 Notes Section 1 Specifications TP-6120 5/02...

  • Page 15: Section 2 Scheduled Maintenance

    Section 2 Scheduled Maintenance Grounding electrical equipment. Hazardous voltage can WARNING cause severe injury or death. Electrocution is possible whenever electricity is present. Open the main circuit breakers of all power sources before servicing the equipment. Configure the installation to electrically ground the generator set and related equipment and electrical circuits to comply with applicable codes and standards.
  • Page 16 Procedure Visually Inspect Check Change Clean Test System Component or Procedure See Section Frequency Fuel Inspect flexible lines and connections. Replace — cracked or spongy hoses. * Check main LP tank supply level, if used. — Inspect fuel piping for damage or corrosion. —...

  • Page 17: Lubrication System

    Start and run the generator set to allow the oil 2.3.2 Engine Oil Recommendation pressure to reach the operating range. Kohler Co. recommends API (American Petroleum b. Check for oil leaks around the oil filter and oil Institute) Service Class SF, SG, or SH 5W-30 synthetic drain plug.

  • Page 18: Oil Cooler

    2.3.4 Oil Cooler WARNING Use compressed air or a brush to clean the oil cooler fins after every 100 hours of operation (or more frequently if the generator set operates under dusty or dirty conditions). See Figure 2-2 for the oil cooler location. Fire.

  • Page 19: Battery

    Air Cleaner Service Procedure c. Check the element cover for damage and fit. Replace all damaged air cleaner components. 1. Disable the generator set. Check the condition of the rubber seal on the air cleaner stud and replace the seal if it is worn or a.

  • Page 20: Ignition System

    Ignition System Description overheating, keep the housing cooling inlets and outlets clean and unobstructed at all times. The COM7.5 engine uses a capacitive discharge ignition system. Refer to the CH20 Engine Service Note: Do not block the generator set cooling air inlet.

  • Page 21: Storage Procedure

    2.10 Storage Procedure 2.10.2 Fuel 1. With the generator set running, shut off the gas Perform the following steps if the generator set is out of supply. service for three months or longer. 2. Run the generator set until the engine stops from 2.10.1 Engine Oil lack of fuel.
  • Page 22 Notes Section 2 Scheduled Maintenance TP-6120 5/02...

  • Page 23: Section 3 General Troubleshooting

    Section 3 General Troubleshooting This section contains generator set troubleshooting and WARNING diagnostic information. Use the following charts to diagnose and correct common problems. First check for simple causes such as a dead engine starting battery or loose connections. Hazardous voltage. Can cause severe injury or death.

  • Page 24: Troubleshooting Chart

    3.1 Troubleshooting Chart The chart includes a list of common problems, possible causes, and recommended corrective actions. Problem Possible Cause Corrective Action Reference Unit does not crank Blown controller fuse Check the fuse and replace if necessary. Maintenance and Service Parts.
  • Page 25 Troubleshooting Chart (continued) Problem Possible Cause Corrective Action Reference Unit stops suddenly Air cleaner clogged Clean or replace the air cleaner element. Section 2.4 Faulty spark plug(s) Replace or regap the spark plugs. Section 2.6.2 Fuel starvation Replenish fuel. — Engine harness loose connection Check and tighten connections.

  • Page 26: Generator Set/Controller System Troubleshooting Flowcharts

    3.2 Generator Set/Controller System Troubleshooting Flowcharts Move master switch to STOP position to reset controller faults. Unplug controller interface connector to disconnect remote control system. Does Does Move master switch to Go to engine engine RUN position. crank? start? Does unit stop Connect the Is the battery while master...
  • Page 27 Is fuel supply Check/replenish fuel Is fuel supply turned on? supply. low? Turn on fuel supply. Have gas provider or Is gas pressure to system owner correct fuel within specifications? pressure problem. Have the fuel supply Has the air been purged installer purge the fuel from the fuel lines? lines.
  • Page 28 Does unit stop Disconnect and while master switch reconnect the harness Does unit lack power is in AUTO and to verify a good or operate erratically? system controller is connection. disconnected? Repair/replace harness. Does unit stop after Go to Unit is okay running normally? Go to Section 3 General Troubleshooting...
  • Page 29 Lacks Power or Runs Erratically Ensure that the main connector is tightly connected. Is the Has air Have fuel supply installer Is fuel controller been purged pressure correct fuel pressure fault LED from fuel 7-11 in. water? problem. lit? lines? Are spark plug wire Have fuel supply Reconnect and/or...
  • Page 30 Lacks Power or Runs Erratically, continued Is fuel solenoid Repair/replace faulty components. and wiring okay? Is fuel pressure regulator okay? Verify that output pressure to Replace pressure regulator. engine is at zero—the engine must draw gas from regulator. Check the fuel adjustment using Adjust fuel an oxygen sensor.
  • Page 31 Unit Stops After Normal Operation Possible intermittent wiring problem or control board malfunction. Check all wiring and components. Start the unit. Does it stop Done. after normal operation? Is the controller Correct the fault and reset fault LED lit? the controller. Are alternator output leads Connect/repair/replace connected to AC terminals...
  • Page 32 Notes Section 3 General Troubleshooting TP-6120 5/02...

  • Page 33: Section 4 Component Testing And Adjustment

    Section 4 Component Testing and Adjustment Use the troubleshooting procedures in Section 3 and the WARNING wiring diagrams in Section 7 to diagnose problems with the generator set operation. For controller operation and test, refer to Section 5 of this manual and to the system controller manual.

  • Page 34: Electronic Governor

    The microprocessor controller monitors the DC output Check the battery connections. Verify that the connections are clean and tight. voltage. To verify accurate voltage control, increase and decrease loads while measuring DC output voltage at Check for a good positive 12-volt DC supply. the output connector.

  • Page 35: Stepper Motor Check

    The fuel shutoff solenoid deenergizes and the generator 4.2.2 Stepper Motor Check set shuts down with the following electronic governor Use the following procedure to test the operation of the faults: governor stepper motor. Loss of pickup while running (throttle moves to closed position) Stepper Motor Test Procedure Engine overspeed...

  • Page 36: Starter

    If there is voltage to the starter motor but the starter the fault condition and reset the controller to clear a fault motor does not crank the engine, refer to the Kohler shutdown. CH20 Engine Service Manual for starter service Note: Always check the wiring and connections before information.

  • Page 37: Fuel Regulators

    4.5.1 Fuel Regulators 4.5.2 Fuel Solenoid Valve The typical gaseous fuel system uses two regulators. The fuel solenoid valve is a 12 VDC valve energized by The primary regulator reduces the line pressure to an lead 70 when the generator set controller is in the crank allowable inlet pressure for the secondary regulator.

  • Page 38: Fuel System Recalibration

    If the fuel system requires recalibration, only trained, authorized service technicians may adjust the fuel metering valves. Always use an oxygen sensor, available from Kohler Co., when adjusting the fuel metering valves. See Maintenance and Service Parts in this manual for the sensor part number.

  • Page 39: Alternator

    4.6 Alternator Stator Test Procedure 1. Disconnect the power to the battery charger, if The alternator is connected directly to the engine. The equipped. alternator uses a permanent-magnet rotor and a 3-lead, 3-phase stator. See Figure 4-9. 2. Disconnect the generator set engine starting battery, negative (--) lead first.

  • Page 40: Rotor

    4.6.2 Rotor Low Oil Pressure (LOP) Switch The normally closed LOP switch opens when the engine The rotor uses permanent magnets. There are no tests oil pressure reaches the normal operating level and or field adjustments for the rotor. closes if the oil pressure drops below a preset minimum. Use an ohmmeter to check the continuity between pin 4.7 Fault Shutdown Switches P1-17 of the engine harness (lead 13) and ground.
  • Page 41 Section 5 Controller Operation and Test This section describes troubleshooting procedures for AUTO position when released, allowing a remote device the generator set control board, shown in Figure 5-1. to start and stop the generator set. See Section 5.1.3 for Refer to the operation manual for operating instructions.
  • Page 42 5.1.3 Remote Start/Stop Connections Abbreviation Definition Set the generator set master switch to the AUTO Crank position for remote operation. For remote starting and stopping, use a three-wire start/stop switch connected Speed sensing to the controller harness. To start the generator set, Speed sensing open a contact between pins 6 (N) and 7 (STT) on the Battery charging alternator...
  • Page 43 5.1.6 Fault Shutdowns on the controller circuit board during the tests. Refer to the service views in Section 1.4 for component The generator set shuts down automatically under the locations. fault conditions listed in Figure 5-3 and cannot be restarted until the controls are reset. The LED on the Follow the enclosure manufacturer’s instructions to control board illuminates to indicate a fault.
  • Page 44 5.2.1 Low Oil Pressure (LOP) Shutdown Overcrank Shutdown Test Procedure 1. Turn off the fuel supply to prevent flooding. The low oil pressure (LOP) switch closes 5 seconds after the oil pressure drops below 5 psi, shutting down 2. Move the generator set master switch to the RUN the generator set and lighting the fault LED on the position.
  • Page 45 5.3 Control Board Tests hands, feet, hair, clothing, and test leads away from the belts and pulleys when the generator set is running. Replace guards, screens, and covers before operating the generator Use the troubleshooting procedures in Section 3 to set.
  • Page 46 Refer to the Engine Service Manual for ignition system service information. The 11. Use the following procedure to calibrate the board. COM7.5 engine uses a capacitive discharge ignition system. Note: The new control board must be calibrated after installation.
  • Page 47 Section 6 Disassembly/Reassembly 6.1 COM7.5 Disassembly 6.1.2 Alternator Disassembly Perform the following steps to disassemble the WARNING alternator for maintenance. 1. Remove four screws from the bearing cover. See Figure 6-1. 2. Remove three screws from the exhaust bracket. Hot engine and exhaust system.
  • Page 48 4. Use a puller or slide hammer to remove the end bracket. The end bracket has two 1/4 in. threaded holes, four inches apart, for use with an adapter bar. See Figure 6-2. 5. Remove the 4 socket head screws that secure the stator.
  • Page 49 6.2 COM7.5 Reassembly 4. Place guide pins or headless bolts in the stator mounting screw holes as a guide for reinstalling the The following sections describe COM7.5 component stator. Stator damage can occur if it is not installed correctly. reinstallation and unit reassembly.
  • Page 50 6. Remove the guides. Clean, install, and torque the 5. Follow the enclosure manufacturer’s instructions socket head screws to 10.8 Nm (8 ft. lbs.). See to reinstall the exhaust ductwork and the Figure 6-9. enclosure. 7. Route the stator leads through the port in the end bracket.
  • Page 51 Section 7 Wiring Diagrams Diagram or Drawing Drawing Number Reference Schematic Diagrams Wiring Diagram ..........GM20551 .
  • Page 52 Figure 7-1 Wiring Diagram, GM20551 Section 7 Wiring Diagrams TP-6120 5/02...
  • Page 53 Figure 7-2 Schematic, ADV-6654 TP-6120 5/02 Section 7 Wiring Diagrams...
  • Page 54 Notes Section 7 Wiring Diagrams TP-6120 5/02...
  • Page 55 Appendix A Abbreviations The following list contains abbreviations that may appear in this publication. A, amp ampere cubic feet per minute exh. exhaust ABDC after bottom dead center center of gravity ext. external alternating current cubic inch displacement Fahrenheit, female analog to digital centerline fglass.
  • Page 56 kilo (1000) MTBF mean time between failure round head machine (screw) kelvin MTBO mean time between overhauls rly. relay kiloampere mtg. mounting root mean square kilobyte (2 bytes) megawatt rnd. round kilogram milliwatt read only memory kg/cm kilograms per square microfarad rot.
  • Page 57 Appendix B Common Hardware Application Guidelines Use the information below and on the following pages to Steps for common hardware application: identify proper fastening techniques when no specific 1. Determine entry hole type: round or slotted. reference for reassembly is made. 2.
  • Page 58 Appendix C General Torque Specifications Use the following torque specifications when service oiled threads. Increase values by 15% for nonplated literature instructions give no specific torque values. threads. All torque values are +0%/--10%. The charts list values for new plated, zinc phosphate, or American Standard Fasteners Torque Specifications Assembled into Assembled into Cast Iron or Steel...
  • Page 59 Appendix D Common Hardware Identification Screw/Bolts/Studs Nuts Hardness Grades Head Styles Nut Styles American Standard Hex Head or Machine Head Hex Head Grade 2 Hex Head or Machine Head Lock or Elastic Grade 5 with Washer Flat Head (FHM) Square Grade 8 Grade 8/9 (Hex Socket Round Head (RHM)
  • Page 64 Phone 920-565-3381, Fax 920-459-1646 For the nearest sales/service outlet in the US and Canada, phone 1-800-544-2444 KohlerPowerSystems.com Kohler Power Systems Asia Pacific Headquarters TP-6120 5/02 7 Jurong Pier Road Singapore 619159 E 2002 by Kohler Co. All rights reserved. Phone (65)264-6422, Fax (65)264-6455...

Table of Contents