The Kohler CH1000 is a 1 L 2-cylinder air-cooled, four-cycle, twin cylinder, overhead valve, with oil cooler engine rated at 3600 rpm, producing up to 23 kW. It powers generator sets from Kohler, including the 18RCAL, 20RCA, 20RES and RESA. It holds 1.9 L (0.5 gal) of oil and 2.5 L (0.7 gal) of coolant.
Also known as: Kohler CH1000
| Oil capacity | 1.9 L |
|---|---|
| Coolant capacity | 2.5 L |
| Displacement | 0.999 L |
| Cylinders | 2 |
| Aspiration | air-cooled, four-cycle, twin cylinder, overhead valve, with oil cooler |
| Rated speed | 3600 rpm |
| Gross power | 23 kW |
Compiled from service & troubleshooting documentation across every generator set that uses the Kohler CH1000.
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | — | 300 hr | |||
| Fuel filter | Kohler Fuel Filter | — | 200 hr | ||
| Oil filter | Cartridge type | 52 050 02-S | 200 hr | Amazon $22.70 eBay | |
| Battery | Group 27 | — | 200 hr | ||
| Belt | Kohler V-Belt | — | 200 hr | ||
| Coolant | Kohler Coolant | 2.5 L | — | 200 hr | |
| Oil | Kohler SAE 10W-30 | 500.0 L | — | 200 hr | |
| Spark plug | — | 300 hr |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| Oil level | Check | 8 hr | Every 8 hours of engine operation | |
| Oil level, 14 kW models | Check | 8 hr | Every 8 hours of engine operation | |
| Oil level, 18/20 kW models | Check | 8 hr | Every 8 hours of engine operation | |
| Oil level, 20 kW models | Check | 8 hr | ||
| Oil level, 26 kW models | Check | 24 hr | ||
| Change oil (14 kW models) | Change | 100 hr | 12 mo | Yearly or 100 hours |
| Engine oil | Change | 100 hr | 12 mo | 14 kW models: 100 hours; 20 kW models: 150 hours |
| Oil (14 kW) | Change | 100 hr | 12 mo | |
| Air cleaner | Replace | 150 hr | 300 hours shown; service more frequently under dusty/dirty conditions | |
| Change oil (20 kW models) | Change | 150 hr | 12 mo | Yearly or 150 hours |
| Oil (20 kW) | Change | 150 hr | 12 mo | |
| Oil cooler (20RCA/RCAL only) | Clean | 150 hr | 12 mo | Yearly or 150 hours; inspect and clean, must be kept free of debris |
| Oil filter (20 kW) | Replace | 150 hr | 12 mo | |
| Replace oil filter (20 kW models) | Replace | 150 hr | 12 mo | Yearly or 150 hours |
| Oil filter | Replace | 200 hr | 12 mo | 14 kW models: 200 hours; 20 kW models: 150 hours |
| Oil filter (14 kW) | Replace | 200 hr | 12 mo | |
| Replace oil filter (14 kW models) | Replace | 200 hr | 12 mo | Yearly or 200 hours |
| Air cleaner service | Clean | 300 hr | 12 mo | Yearly or 150/300 hours depending on model; more often under dusty/dirty conditions |
| Brushes and collector ring | Inspect | 300 hr | 12 mo | Yearly or 300 hours; authorized distributor/dealer only |
| Generator brushes and collector ring | Replace | 300 hr | 12 mo | Authorized distributor only |
| Spark plugs | Replace | 300 hr | 12 mo | 150-300 hours shown |
| Crankcase breather hose | Inspect | 500 hr | 12 mo | Yearly or 500 hours |
| Crankcase breather hose | Replace | 500 hr | 12 mo | Yearly or 500 hours |
| Replace stepper motor coupling and bushing | Replace | 500 hr | Authorized distributor/dealer only | |
| Wire-cable insulation condition | Inspect | 500 hr | 36 mo | 3 years or 500 hours |
| Wire-cable insulation condition | Test | 500 hr | 36 mo | 3 years or 500 hours |
| AC electrical system visible wear or damage | Inspect | 3 mo | Quarterly | |
| Air ducts and louvers | Clean | 12 mo | ||
| Air ducts, louvers | Clean | 12 mo | Yearly; visually inspect and clean | |
| Battery | Check | 1 mo | Check charger operation, charge rate | |
| Battery and rack corrosion | Clean | 12 mo | Yearly | |
| Battery charger operation, charge rate | Check | 1 mo | Monthly | |
| Battery electrolyte level and specific gravity | Check | 12 mo | Yearly; not necessary for maintenance-free batteries | |
| Battery terminals and boots | Clean | 12 mo | Yearly | |
| Clean and tighten battery terminals and inspect boots | Clean | 12 mo | Yearly | |
| Control and power wiring connections | Check | 12 mo | Tighten; Yearly | |
| Exhaust insulation, fire hazards | Inspect | 12 mo | Yearly | |
| Flexible fuel lines and connections | Inspect | 3 mo | Replace as necessary; Quarterly | |
| Fuel flexible lines and connections | Inspect | 3 mo | Visually inspect; replace as necessary; quarterly | |
| Fuel piping | Inspect | 12 mo | Yearly |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Gap | Spark plug | 0.03 | in. | |
| Gap | Spark plug | 0.76 | mm | |
| Gap | Spark plug gap | 0.51 | mm (0.02 in.) | |
| Gap | Spark plug gap | 0.7--0.8 | mm (0.028--0.030 in.) | |
| Gap | Spark plug gap | 0.76 | mm (0.030 in.) | |
| Gap | Spark plug gap | 0.8--0.9 | mm (0.03--0.04 in.) | |
| Gap | Spark plug gap | 0.89 | mm (0.035 in.) | |
| Gap | Spark plug gap | 0.9--1.0 | mm (0.036--0.04 in.) | |
| Other | Battery wrap length | 1067 (42) | mm (in.) | |
| Other | Battery wrap length | 864 (34) | mm (in.) | |
| Other | Engine cooldown time delay | 5 | minutes | |
| Other | Engine start crank cycle | 3 attempts, 15 sec crank / 15 sec off | ||
| Other | Governed frequency high shutdown | 110 | % of frequency setpoint for >10 sec | 10 sec inhibit after engine start |
| Other | Governed frequency low shutdown | 90 | % of frequency setpoint for >10 sec, or 1 Hz below setpoint for >60 sec | 10 sec inhibit after engine start |
| Other | Heater wrap rating | 50 | Watts | |
| Other | Heater wrap rating | 65 | Watts | |
| Other | Plug cord length | 75 (3) | mm (in.) | |
| Other | Power cord length | 1677 (66) | mm (in.) | |
| Other | Power cord length | 1830 (72) | mm (in.) | |
| Other | Power cord length | 483 (19) | mm (in.) | |
| Pressure | LPG fuel supply | 1.7-2.7 | kPa | |
| Pressure | Natural gas fuel supply | 0.9-2.7 | kPa | |
| Speed | Engine overspeed shutdown | 115 | % of normal running speed for >0.3 sec | |
| Speed | Engine speed high shutdown | 115 | % of normal running speed for >0.3 sec | |
| Speed | Engine speed low shutdown | 85 | % of normal running speed for >3 sec | |
| Speed | Engine underspeed shutdown | 85 | % of normal running speed for >3 sec | |
| Temperature | Carburetor heater thermostat OFF | 16 ± 3 | C (60 ± 5F) | |
| Temperature | Carburetor heater thermostat ON | 4 ± 4 | C (40 ± 7F) | |
| Temperature | Exhaust temperature | 260 | C | at rated kW |
| Temperature | Thermostat OFF | 16 ± 3 | °C | Thermostat OFF (60 ± 5°F) |
| Temperature | Thermostat ON | 4 ± 4 | °C | Thermostat ON (40 ± 7°F) |
| Temperature | Thermostat off temperature | 27 | C (80 F) | |
| Temperature | Thermostat on temperature | 16 | C (60 F) | |
| Torque | Spark plug | 18 | ft. lb. | |
| Torque | Spark plug | 22 | ft. lb. | |
| Torque | Spark plug | 24.4 | Nm | |
| Torque | Spark plug | 24.4-29.8 | Nm (18-22 ft. lb.) | |
| Torque | Spark plug | 29.8 | Nm | |
| Torque | Spark plug torque | 15 | Nm (11 ft. lb.) | |
| Torque | Spark plug torque | 18 | Nm (13.3 ft. lb.) | |
| Torque | Spark plug torque | 24.4--29.8 | Nm (18--22 ft. lb.) | |
| Torque | Spark plug torque | 25 | Nm (18 ft. lb.) | |
| Voltage | Battery charger output | 13.4 ±2% | VDC, max 2.5 A | |
| Voltage | Battery specific gravity, fully charged | 1.260 | specific gravity | corrected to 80°F (26.7°C) |
| Voltage | Battery specific gravity, needs charging | below 1.215 | specific gravity | corrected to 80°F (26.7°C) |
| Voltage | Engine starting electrical system | 12 | VDC, negative ground | |
| Voltage | Generator output voltage high shutdown | 120 | % of nominal system voltage for >2 sec | |
| Voltage | Generator output voltage low shutdown | 80 | % of nominal system voltage for >10 sec | |
| Voltage | Voltage regulation | 1.0 | % | 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.
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Engine oil | 10W-50 extended-life synthetic | 1.9 L (qt.) | Premium oil option, 26 kW models, requires fewer oil changes | ||
| Engine oil | 5W-30 or 10W-30 | API (American Petroleum Institute) Service Class SG, SH, or SJ synthetic oil | 1.8 L (1.9 qt.) - 14 kW models | 20 kW models: 1.9 L (2.0 qt.) | |
| Engine oil | 5W-30 or 10W-30 API Service Class SG, SH, or SJ synthetic | API SG/SH/SJ | 1.8 L (qt.) | 14 kW models | |
| Engine oil | Synthetic, API Service Class SG or higher | API SG or higher | Check oil level at or near, not over, full mark on dipstick before operation | ||
| Fuel | Natural gas or propane | Certified for emergency standby use only | |||
| Fuel | Natural Gas or LPG | Natural gas: 90% min methane. LPG: 85% min propane. Fuel supply pressure: Natural gas 0.9-2.7 kPa, LPG 1.7-2.7 kPa | |||
| Fuel | Natural gas or LPG | Generator 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.
| Code | Name | Meaning | Severity | Action |
|---|---|---|---|---|
| AC Sens Loss | AC Sensing Lost | In Auto mode, generator output AC sensing is lost. Detection begins 10 seconds after crank disconnect. | Warning | Contact authorized distributor/dealer for service |
| ATS ComError | ATS Communication Error | Warning is displayed if ATS interface connection is lost | Warning | Check communication wiring between transfer switch interface board and generator set. |
| ATS PhaseRot | ATS PhaseRot | Transfer switch phase rotation does not match; ATS will not transfer | Warning | Correct the ATS connection. Refer to the ATS Installation manual, wiring diagrams, and labels on the transfer switch. |
| Accy PwrOver | Accessory Power Overload | An over current fault (short circuit) on the accessory controller power output | Warning | Contact authorized distributor/dealer for service |
| Accy PwrOver Warning | Accy PwrOver Warning | An over current fault (short circuit) on the accessory controller power output. | Warning | Contact an authorized distributor/dealer for service |
| Advanced Diagnostic | Advanced Diagnostic | Shutdown during the reduced speed portion of an exercise. Event history shows Advanced Diagnostic Active. Engine restarts, runs at full speed for 2 minutes, and stops. Controller returns to AUTO mode. | Shutdown | If the generator set does not restart and return to AUTO, check for other faults that prevent generator set operation. |
| Aux Input | Auxiliary Input | Optional customer-connected input (from PIM) is closed | Shutdown | Check customer-supplied equipment. |
| Batt Chg Flt | Battery Charger Fault | Input to PIM from an external battery charger (not the built-in battery charger). | Warning | Check external battery charger. |
| Battery CrLo | Battery Crank Low | Engine starting battery voltage falls below 11 VDC for more than 10 seconds | Warning | Clears when battery voltage returns to acceptable level |
| Battery CrLo Warning | Low Cranking Battery Voltage Warning | Engine starting battery voltage falls below 11 VDC for more than 10 seconds. Inhibited during crank cycle. Clears when battery voltage returns to acceptable level. | Warning | Check the battery rating and condition. Check the battery charger operation. Charge or replace the battery. |
| Battery High | Battery High | Engine starting battery voltage rises above 16 VDC for more than 10 seconds (inhibited during crank) | Warning | Check battery rating/condition and charger operation |
| Battery Voltage High | Battery Voltage High | Engine starting battery voltage rises above 16 VDC for more than 10 seconds. Inhibited during crank cycle. Clears when voltage returns to acceptable level. | Warning | Check the battery rating and condition. Check the battery charger operation. |
| Battery Voltage Low | Battery Voltage Low | Engine starting battery voltage falls below 12.5 VDC for more than 90 seconds when engine not running. Not operative during crank cycle. Clears when voltage returns to acceptable level. | Warning | Check the battery rating and condition. Check the battery charger operation. Charge or replace the battery. |
| Eng Speed High | Eng Speed High | Engine speed exceeds 115% of normal running speed for more than 0.3 seconds | Shutdown | Contact an authorized distributor/dealer for service |
| Eng Speed Low | Eng Speed Low | Engine speed drops below 85% of normal running speed for more than 3 seconds | Shutdown | Reduce the load; on 20RCA/RCAL check enclosure thermostat; contact dealer if it persists |
| Engine Speed High | Engine Speed High | Engine speed exceeds 115% of the normal running speed for more than 0.3 seconds. | Shutdown | Contact an authorized dealer for service. |
| Engine Speed Low | Engine Speed Low | Engine speed drops below 85% of the normal running speed for more than 3 seconds. | Shutdown | Reduce the load. Check enclosure thermostat and reset if tripped. Contact an authorized dealer for service. |
| Exer Not Sch | Exercise Not Scheduled | No exercise is scheduled on the controller. | Warning | Set the exerciser per Section 3.6 |
| Frequency High | Frequency High | Governed frequency exceeds 110% of the system's frequency setpoint for more than 10 seconds. Active 10 seconds after engine start. | Shutdown | Contact an authorized distributor/dealer for service |
| Frequency Low | Frequency Low | Governed frequency falls below 90% of the system frequency setting for more than 10 seconds, or 1 Hz below setting for more than 60 seconds. Active 10 seconds after engine start. | Shutdown | Reduce the load and restart; on 20RCA/RCAL check enclosure thermostat; contact dealer if it persists |
| Lo Crank Vlt | Low Cranking Voltage | Battery voltage dropped below 3.5 VDC during engine cranking. | Warning | Charge or replace the battery. |
| Locked Rotor | Locked Rotor | No engine rotation sensed during cranking; shuts down 3 seconds after detection | Shutdown | Check the battery. Check for loose connections. Contact an authorized dealer for service. |
| Low Oil Level or Oil Pressure | Low Oil Level or Oil Pressure | Oil level switch on the 26 kW indicates low oil level. LOP switch indicates low oil pressure for more than 5 seconds. Active 30 seconds after crank disconnect. Does not protect against low oil level. | Shutdown | Check for leaks in the lubrication system. Check the oil level and add oil if low. Check the oil level or oil pressure switch and wiring. If fault persists, do not run the generator set; contact an authorized dealer. |
| MainPwrOverL | MainPwrOverL | Main power overload; an over current fault on the controller output (short circuit). | Shutdown | Contact an authorized distributor/dealer for service |
| Not in Auto | Not in Auto | The generator set is not in Automatic (standby) mode. Remote start and stop commands from a transfer switch or remote switch will be ignored. | Warning | Press AUTO to place the generator set in Automatic mode, when appropriate. |
| Oil Press Low | Oil Pressure Low | The LOP switch indicates low oil pressure for more than 5 seconds. Function becomes active 30 seconds after crank disconnect (30 second inhibit). The low oil pressure shutdown does not protect against low oil level. | Shutdown | Check for leaks in the lubrication system. Check the oil level and add oil if the level is low. Check the oil pressure switch and wiring. If the fault persists, do not run the generator set. Contact an authorized dealer for service. |
| Over Crank | Over Crank | Three unsuccessful starting attempts. | Shutdown | Check the fuel supply, spark plug, and battery. Check for loose connections. Contact an authorized dealer for service. |
| Spd Sens Flt | Speed Sensor Fault | Engine speed sensor has failed or engine stalled. | Shutdown | Contact an authorized distributor/dealer for service |
| Volts L1-L2 High | Volts L1-L2 High | Output voltage exceeds 120% of the system nominal voltage for more than 2 seconds. | Shutdown | Contact an authorized distributor/dealer for service |
| Volts L1-L2 Low | Volts L1-L2 Low | Output voltage falls below 80% of the nominal system voltage for more than 10 seconds. | Shutdown | Reduce the load and restart; on 20RCA/RCAL check enclosure thermostat; contact dealer if it persists |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Tools: digital voltmeter, personal computer, SiteTech software
Tools: digital voltmeter
Tools: clamp-on DC current probe or DC current meter
⚠ Always identify and correct cause of fault before resetting
⚠ Battery acid can cause severe injury or death
⚠ Explosion hazard from battery gases
⚠ Disconnect battery before working on generator set
⚠ Explosive fuel vapors can cause severe injury or death
Tools: straight-blade screwdriver, gas leak detector
⚠ Explosive fuel vapors can cause severe injury or death
Tools: gas leak detector
⚠ 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.
⚠ 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.
⚠ 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.
⚠ 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.
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Voltage | Phase | Connection | Leads | Notes |
|---|---|---|---|---|
| 12-volt engine electrical system, single starter motor, negative ground | Battery negative to ground terminal on or near starter motor; battery positive to positive terminal on starter solenoid | All generator set models use a negative ground with a 12-volt engine electrical system | ||
| Engine start connection for non-RXT transfer switch or remote start/stop switch | Terminals 3 and 4 on generator set terminal block | Route engine start leads through separate conduit from AC power and load leads | ||
| RXT transfer switch to generator set terminal block A, B, PWR, COM | P10-1 through P10-4 (transfer switch) to A, B, PWR, COM (generator set) | Terminal block connections 3 and 4 not used with Model RXT ATS | ||
| 100/200 | 1 | Single | ||
| 100/200 | 3 | Delta | ||
| 110/220 | 1 | Single | ||
| 110/220 | 3 | Delta | ||
| 115/230 | 1 | Single | ||
| 12 VDC | Single starter motor, negative ground engine electrical system | Positive (+) to starter solenoid terminal; negative (-) to ground terminal on or near starter motor | Remove negative lead first when disconnecting, reconnect negative lead last | |
| 120 | 1 | Single | Genset System Voltage/Frequency/Phase table for controller setup | |
| 120/208 | 3 | Wye | ||
| 120/208, 120/240, 277/480 | 3 | 3-phase 2G7 | 12 | |
| 120/240 | 1 | 2F7 (4 lead) | 4 | Single phase, 1.0 power factor |
| 120/240 | 1 | Single | ||
| 120/240 | 1 | Single phase | 4 | 1.0 power factor |
| 120/240 | 1 | Single phase 2F7 | 4 | |
| 120/240 | 3 | Delta | ||
| 127/220 | 3 | Wye | ||
| 220 | 1 | Single | ||
| 220/380 | 3 | Wye | ||
| 230 | 1 | Single | ||
| 230/400 | 3 | Wye | ||
| 240 | 1 | Single | ||
| 240/416 | 3 | Wye | ||
| 277/480 | 3 | Wye |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
The Kohler CH1000 engine has an oil capacity of 1.9 liters.
The Kohler CH1000 has a displacement of 0.999 liters with 2 cylinders.
The Kohler CH1000 powers 4 generator set(s), including Kohler 18RCAL, Kohler 20RCA, Kohler 20RES, Kohler RESA.
The Kohler CH1000 oil change interval is every 200 hours.
A commonly reported issue on generators using the Kohler CH1000 is: 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..