Facts About Generators
GeneratorsDirectoryCompareRepairEnginesControllersPartsManufacturersGuides
Search models or part #
Home›Engines›Kohler Command PRO OHV CH1000

Kohler Command PRO OHV CH1000 Engine

The Kohler Command PRO OHV CH1000 is a 999 L engine rated at 3600 rpm. It powers generator sets from Kohler, including the 20RES.

Also known as: KOHLER Command PRO OHV CH1000

999.0 L
Displacement
3600 rpm
Rated speed
On this pageSpecsGenerator setsFAQService intervalsTorque & specsFluidsFault codesProceduresWiring

Engine specifications

Displacement999.0 L
Rated speed3600 rpm

Common problems

15
  • The generator set does not crank.
    Cause: Battery weak or dead.
    Fix: Recharge or replace the battery.
  • The generator set cranks but does not start, starts hard, lacks power, or operates erratically.
    Cause: Air cleaner clogged.
    Fix: Clean and/or replace the air cleaner.
  • Remote stop command received from a remote switch, ATS, or OnCuerPlus.
    Fix: Check the remote switch position. Check OnCuerPlus.
  • Overcrank shutdown.
    Fix: Reset the controller. If the overcrank fault occurs again, contact an authorized distributor/dealer.
  • No fuel.
    Fix: Check fuel valves and fuel supply.
  • No AC output.
    Cause: Line circuit breaker in the OFF position.
    Fix: Place the circuit breaker in the ON position.
  • Low output or excessive drop in voltage.
    Cause: Generator set overloaded.
    Fix: Reduce the load.
  • Low oil pressure shutdown.
    Fix: Check for oil leaks. Check the oil level and add oil if necessary.
  • Line circuit breaker tripping because of short circuit.
    Fix: Contact an authorized distributor/dealer for service.
  • Line circuit breaker tripping because of overload.
    Fix: Reduce the load on the generator set.
  • Hot engine and exhaust system
    Fix: Do not work on the generator set until it cools.
  • Generator thermostat tripped.
    Fix: Check for obstructed air inlets and outlets. Reset the thermostat. See Section 5.5.
  • Generator set stops suddenly.
    Cause: Low oil pressure shutdown.
    Fix: Check for oil leaks. Check the oil level and add oil if necessary.
  • Generator set in the OFF mode.
    Fix: Press the RUN button to start the engine or press AUTO to allow remote starting.
  • Generator set circuit breaker trips repeatedly
    Fix: Contact an authorized distributor/dealer for service.

Compiled from service & troubleshooting documentation across every generator set that uses the Kohler Command PRO OHV CH1000.

Service intervals

17
ItemActionHoursMonthsNotes
Oil levelCheck8 hrBefore each use or every 8 hours for extended operation
Engine oilChange100 hr12 mo14 kW models: 100 hours; 20 kW models: 150 hours
Oil (14 kW)Change100 hr12 mo
Air cleanerReplace150 hr300 hours shown; service more frequently under dusty/dirty conditions
Air cleaner serviceClean150 hr12 mo14 kW: 150/300 hours; 20 kW: 150/300 hours yearly
Oil (20 kW)Change150 hr12 mo
Oil filter (20 kW)Replace150 hr12 mo
Oil filterReplace200 hr12 mo14 kW models: 200 hours; 20 kW models: 150 hours
Oil filter (14 kW)Replace200 hr12 mo
Generator brushes and collector ringReplace300 hr12 moAuthorized distributor only
Spark plugsReplace300 hr12 mo150-300 hours shown
Crankcase breather hoseInspect500 hr12 moYearly or 500 hours
Air ducts and louversClean12 mo
BatteryCheck1 moCheck charger operation, charge rate
Fuel flexible lines and connectionsInspect3 moQuarterly; replace as necessary
Fuel pipingInspect12 moYearly
Main tank fuel supply levelCheck0 moWeekly

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

32
TypeItemValueUnitCondition
GapSpark plug0.03in.
GapSpark plug0.76mm
GapSpark plug gap0.51mm (0.02 in.)
GapSpark plug gap0.7--0.8mm (0.028--0.030 in.)
GapSpark plug gap0.76mm (0.03 in.)
GapSpark plug gap0.8--0.9mm (0.03--0.04 in.)
GapSpark plug gap0.89mm (0.035 in.)
GapSpark plug gap0.9--1.0mm (0.036--0.04 in.)
OtherBattery wrap length1067 (42)mm (in.)
OtherBattery wrap length864 (34)mm (in.)
OtherHeater wrap rating50Watts
OtherHeater wrap rating65Watts
OtherPlug cord length75 (3)mm (in.)
OtherPower cord length1677 (66)mm (in.)
OtherPower cord length1830 (72)mm (in.)
OtherPower cord length483 (19)mm (in.)
TemperatureCarburetor heater thermostat OFF16 ± 3C (60 ± 5F)
TemperatureCarburetor heater thermostat ON4 ± 4C (40 ± 7F)
TemperatureExhaust temperature260Cat rated kW
TemperatureThermostat OFF16 ± 3°CThermostat OFF (60 ± 5°F)
TemperatureThermostat ON4 ± 4°CThermostat ON (40 ± 7°F)
TemperatureThermostat off temperature27C (80 F)
TemperatureThermostat on temperature16C (60 F)
TorqueSpark plug18ft. lb.
TorqueSpark plug22ft. lb.
TorqueSpark plug24.4Nm
TorqueSpark plug29.8Nm
TorqueSpark plug torque15Nm (11 ft. lb.)
TorqueSpark plug torque18Nm (13.3 ft. lb.)
TorqueSpark plug torque24.4--29.8Nm (18--22 ft. lb.)
TorqueSpark plug torque25Nm (18 ft. lb.)
VoltageVoltage regulation1.0%no-load to full-load RMS

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
Engine oil5W-30 or 10W-30API Service Class SG, SH, or SJ synthetic1.8 L14 kW models; synthetic oil oxidizes and thickens less
FuelNatural gas or propaneCertified for emergency standby use only
FuelNatural Gas or LPGNatural gas: 90% min methane. LPG: 85% min propane. Fuel supply pressure: Natural gas 0.9-2.7 kPa, LPG 1.7-2.7 kPa
FuelNatural gas or LPGGenerator set is certified for emergency standby operation only

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Fault codes

5
CodeNameMeaningSeverityAction
AC Sens LossAC Sensing LostIn Auto mode, generator output AC sensing is lost. Detection begins 10 seconds after crank disconnect.WarningContact authorized distributor/dealer for service
ATS ComErrorATS Communication ErrorWarning is displayed if ATS interface connection is lostWarningCheck communication wiring between transfer switch interface board and generator set
ATS PhaseRotATS Phase Rotation MismatchTransfer switch phase rotation does not match; ATS will not transferWarningCorrect the ATS connection per ATS Installation manual and labels
Accy PwrOverAccessory Power OverloadAn over current fault (short circuit) on the accessory controller power outputWarningContact authorized distributor/dealer for service
Battery CrLoBattery Crank LowEngine starting battery voltage falls below 11 VDC for more than 10 secondsWarningClears when battery voltage returns to acceptable level

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

12
RDC2 Voltage Calibration Using SiteTech adjustment

Tools: digital voltmeter, personal computer, SiteTech software

  1. Connect PC to controller via USB
  2. With generator off, connect multimeter across L1/L2 (AC volts)
  3. Start generator set
  4. Compare voltmeter reading to controller display
  5. Calculate new Genset Calibration Factor Voltage using (Vmeter / Vcontrol) x Fold = Fnew
  6. Enter new value into SiteTech and click Apply Changes
  7. Verify voltmeter matches controller display
  8. Repeat for L2-L3 and L3-L1 if three-phase
  9. Press OFF to stop generator set
RDC2 Voltage Calibration Using the Controller Keypad adjustment

Tools: digital voltmeter

  1. With generator off, connect digital multimeter across L1 and L2, set to AC volts
  2. Start generator set with RUN button
  3. Navigate to Generator Metering menu, press Select; Volts L1-L2 displayed
  4. Press Select; voltage number flashes
  5. Use up/down arrows to match voltmeter reading
  6. Press Select to confirm
  7. Step to Return screen
  8. Press OFF to stop generator set
Resetting the Maintenance Timer adjustment
  1. From Overview menu, step down to Genset Run Time menu.
  2. Press Select button and step down to Next Maintenance screen.
  3. Press Select button.
  4. Press Up arrow button so 'Reset Maint Timer? Yes' is displayed.
  5. Press Select button.
  6. Wait about two minutes for new maintenance interval and date to display.
VSC Current (Load) Calibration Using the Controller Keypad adjustment

Tools: clamp-on DC current probe or DC current meter

  1. Connect DC current probe/clamp meter to measure generator current
  2. Start generator with RUN button
  3. Adjust system voltage to obtain rated current output with battery bank attached (or use load bank)
  4. Trip output breaker
  5. Navigate to Generator Metering menu, select Generator Load
  6. Press and hold Select for No-Load Calibration; verify breaker open, confirm Yes
  7. Close output breaker; verify rated output current, confirm Yes
  8. Verify displayed load is correct; recalibrate if necessary
  9. Press OFF to stop generator set
Install Carburetor Heater, 17/18/20 kW Models installation

⚠ Accidental starting can cause severe injury or death; disconnect battery cables before working on the generator set, negative lead first.

⚠ Hazardous voltage will cause severe injury or death; disconnect all power sources before opening the enclosure.

⚠ Hot surfaces: disconnect power to the heater and allow it to cool before servicing.

  1. Open enclosure roof; locate controller and air cleaner.
  2. Turn off the generator set (master switch or controller OFF button, per model).
  3. Disconnect AC power to the generator set at the distribution panel breaker.
  4. Disconnect the starting battery, negative lead first.
  5. Check nameplate model/spec number and locate heater position per Figure 4.
  6. Remove the air cleaner cover if needed for access.
  7. Disconnect the heating element from the power cord at the plug connector.
  8. Insert the heating element into the threaded opening on the engine and tighten.
  9. Reconnect the power cord to the heater.
  10. Route and connect the power cord per the applicable model wiring option (steps 10-12).
  11. Replace the air cleaner cover if it was removed.
  12. Affix decal GM22387 onto the air cleaner cover.
  13. Reconnect the starting battery, negative lead last.
  14. Reconnect AC power by closing the distribution panel breaker.
  15. For standby operation, move switch to AUTO and reinstall enclosure panels.
Install Carburetor Heater, Models 8-12RESV/RESVL installation

⚠ Accidental starting can cause severe injury or death; disconnect battery cables before working on the generator set, negative lead first.

⚠ Hazardous voltage will cause severe injury or death; disconnect all power sources before opening the enclosure.

⚠ Hot surfaces: install the heater before connecting it to power; disconnect power and allow it to cool before servicing.

  1. Open the enclosure roof.
  2. Press the OFF button on the generator set controller.
  3. Disconnect AC power to the generator set at the distribution panel breaker.
  4. Disconnect the starting battery, negative lead first.
  5. Locate the carburetor heater per Figure 14; remove side panel or air cleaner cover if needed.
  6. Remove and discard the M8 bolt from the carburetor at the heater location.
  7. Thread adapter GM91361 into the M8 hole.
  8. Insert carburetor heater GM57968 into the adapter and tighten.
  9. Connect the extension cord (GM91360 or 3-way GM95628) to the heater cord.
  10. Route the cord to the AC receptacle, securing away from throttle linkage and exhaust.
  11. Plug the cord into the AC receptacle on the generator bulkhead.
  12. Affix decal GM22387 onto the air cleaner cover.
  13. Reconnect the starting battery, negative lead last.
  14. Reconnect AC power by closing the distribution panel breaker.
  15. Press AUTO for standby operation and reinstall enclosure panels.
Installation Procedure, 17/18/20 kW Models installation

⚠ Disconnect battery cables before working on generator set; remove negative lead first.

⚠ Disconnect all power sources before opening enclosure.

⚠ Install heater before connecting power; allow to cool before servicing.

  1. Open enclosure roof; locate controller and engine air cleaner.
  2. Turn off generator set: 17/18RES/RESL move master switch OFF; 20RES/RESL press OFF and remove fuse F3; 20RESA/AL/B/C/CL/D press OFF.
  3. Disconnect AC power by opening circuit breaker in distribution panel.
  4. Disconnect engine starting battery, negative lead first.
  5. Check nameplate model/spec; see Figure 4 for heater location. Heater fits threaded opening on carburetor below air cleaner.
  6. Remove air cleaner cover if easier access needed.
  7. Disconnect heater element from power cord at plug connector (GM57968 or GM88228).
  8. Insert heating element into threaded opening on engine and tighten.
  9. Reconnect power cord to heater.
  10. For 17/18RES/RESL and 20RES/RESL: remove air intake panel; install bushing X-634-15 or X-634-16; route cord through bulkhead; plug into 120 VAC receptacle under controller.
  11. For 120 V 20RESA/AL/B/C/CL/D: route cord away from hot parts; plug into receptacle in engine compartment; use 3-way cord GM95628 if multiple accessories; secure excess cable.
  12. For 240 V 14/20RESA and 20RESC: remove controller screws, remove bulkhead knockout, route cord and insert plug; disconnect 120 VAC harness at 3-pin; connect 3-pin to new 240 VAC connector.
  13. Replace air cleaner cover if removed; affix decal GM22387 as shown.
  14. Check master switch OFF (17/18); reconnect battery, negative last; close distribution breaker. 20RES/RESL: reinstall fuse F3.
  15. For standby, move master switch to AUTO or press AUTO. Reinstall enclosure panels; close and lock roof.
Installation Procedure, Models 8-12RESV/RESVL installation

⚠ Disconnect battery cables before working on generator set; remove negative lead first.

⚠ Disconnect all power sources before opening enclosure.

⚠ Install heater before connecting power; allow to cool before servicing.

  1. Open enclosure roof.
  2. Press OFF button on generator set controller.
  3. Disconnect AC power by opening circuit breaker in distribution panel.
  4. Disconnect engine starting battery, negative lead first.
  5. See Figure 13 for heater location. Remove louvered side panel and/or air cleaner cover for access if necessary.
  6. Remove and discard M8 bolt from carburetor at heater location.
  7. Thread adapter GM91361 into M8 hole.
  8. Insert carburetor heater GM57968 into adapter and tighten.
  9. Connect extension cord GM91360 or 3-way extension cord GM95628 to heater cord.
  10. Route cord to AC receptacle as shown; secure with cable ties away from throttle linkage and exhaust.
  11. Plug cord into AC receptacle on generator bulkhead.
  12. Affix decal GM22387 onto air cleaner cover.
  13. Reconnect battery, negative lead last.
  14. Reconnect AC power by closing circuit breaker.
  15. For standby, press AUTO. Reinstall enclosure panels; close and lock roof.
Air Cleaner Element and Precleaner maintenance
  1. Disable set: press OFF button, disconnect battery charger power, remove battery cables, negative (--) lead first.
  2. Loosen the cover retaining knob(s) or release the retaining clips and remove the cover.
  3. Remove and discard the old air cleaner element and precleaner (if equipped).
  4. Install the precleaner over the new air cleaner element.
  5. Install the paper element onto the air cleaner base, making sure it is flat and properly seated.
  6. Reinstall the element cover, element cover nut, and the air cleaner cover; secure with the knob(s) or clips.
  7. 15RES/30RES and RCL models: wipe cover and housing with a clean rag and make sure sealing surfaces fit correctly.
  8. Reconnect the battery cable, negative (--) lead last.
Air Cleaner Service (14 kW Models) maintenance

⚠ Do not wash paper element or clean with pressurized air

  1. Press OFF button on generator set controller.
  2. Disconnect utility power.
  3. Disconnect engine starting battery, negative lead first.
  4. Loosen cover retaining knob and remove cover.
  5. Remove element cover nut, element cover, and paper element.
  6. Replace element if dirty, bent, or damaged.
  7. Check air cleaner base for security and damage.
  8. Check element cover for damage and fit.
  9. Remove any loose dirt or debris from air cleaner base.
  10. Wipe base carefully so no dirt enters intake throat.
  11. Check condition of rubber seal on air cleaner stud.
  12. Reinstall paper element, element cover, element cover nut, and air cleaner cover.
  13. Secure cover with cover retaining knob.
  14. Reconnect utility power.
  15. Reconnect engine starting battery, negative lead last.
Air Cleaner Service (20 kW Models) maintenance

⚠ Do not wash paper element or use pressurized air

  1. Loosen two cover retaining knobs and remove cover.
  2. Remove paper element.
  3. Replace dirty, bent, or damaged element.
  4. Handle new elements carefully; do not use if sealing surfaces are damaged.
  5. When servicing, check air cleaner base is secured and not damaged.
  6. Check element cover for damage or improper fit.
  7. Remove any loose dirt or debris from air cleaner base.
  8. Reinstall paper element onto air cleaner base ensuring flat and properly seated.
  9. Install air cleaner cover and secure with two retaining knobs.
  10. Order genuine Kohler parts for element replacement.
Firmware Update Using SiteTech maintenance

⚠ Do not load RDC2.4 firmware onto a red- or green-board controller

Tools: personal computer, USB cable, SiteTech software

  1. Download latest firmware file (.bin) from Kohler Power Resource Center or dealer portal
  2. Connect controller to PC via USB cable
  3. Start SiteTech; program recognizes connected device
  4. Click Update Firmware
  5. Browse to and select firmware file, click Open
  6. Verify current/new version and file name, click Update Firmware
  7. Wait for 'Firmware Updated Successfully' message, click Close

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

VoltagePhaseConnectionLeadsNotes
100/2001Single
100/2003Delta
110/2201Single
110/2203Delta
115/2301Single
1201SingleGenset System Voltage/Frequency/Phase table for controller setup
120/2083Wye
120/2401Single
120/2401Single phase41.0 power factor
120/2403Delta
127/2203Wye
2201Single
220/3803Wye
2301Single
230/4003Wye
2401Single
240/4163Wye
277/4803Wye

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Common questions

What is the displacement of the Kohler Command PRO OHV CH1000?

The Kohler Command PRO OHV CH1000 has a displacement of 999.0 liters.

Which generators use the Kohler Command PRO OHV CH1000 engine?

The Kohler Command PRO OHV CH1000 powers 1 generator set(s), including Kohler 20RES.

What is a common problem with the Kohler Command PRO OHV CH1000 engine?

A commonly reported issue on generators using the Kohler Command PRO OHV CH1000 is: The generator set does not crank.. Cause: Battery weak or dead.. Fix: Recharge or replace the battery..