Specifications
| Fuel | natural gas or propane |
|---|---|
| Frequency | 60.0 Hz |
| Standby power | 7 kW |
| Standby kVA | 7 |
| Prime power | 7 kW |
| Controller | ADC 2100, ADC-RES, ADC-RES Advanced Digital, Advanced Digital, Advanced Digital (ADC 2100), Advanced Digital Features |
| Oil capacity | 1.9 L |
| Alternator | Kohler 2F4 |
| Voltage options | 120/240 V, 115/230 V |
| Phase | 1 |
| Rated current | 35 A |
| Power factor | 1.0 |
| Battery cranking | 675 CCA |
| Battery voltage | 12 V |
| Battery quantity | 1 |
| Dimensions (L×W×H) | 1079×774×826 mm |
| Dry weight | 182 kg |
| Sound level | 65.0 dBA @ 7 m |
Maintenance & consumables
for the Kohler CH-20| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | 24 083 02 | 500 hr | PartsGeek | ||
| Fuel filter | Fuel Filter | — | 8 hr | find | |
| Oil filter | 12 050 01 | 500 hr | Amazon eBay $19.49 PartsGeek | ||
| Belt | Belt | — | 500 hr | find | |
| Coolant | Cooling System | — | |||
| Coolant filter | Inspect and clean the oil cooler | — | 500 hr | find | |
| Oil | Change oil | ADV--6823 | 100 hr | PartsGeek |
Common questions
What is the power rating of the Kohler 8.5 RES?
The Kohler 8.5 RES is rated 7 kW standby (7.0 kVA).
What engine does the Kohler 8.5 RES use?
The Kohler 8.5 RES is powered by the Kohler CH-20 engine.
What fuel does the Kohler 8.5 RES use?
The Kohler 8.5 RES runs on natural gas or propane.
What is the oil capacity of the Kohler 8.5 RES?
The Kohler CH-20 engine in the Kohler 8.5 RES has an oil capacity of 1.9 liters.
What alternator does the Kohler 8.5 RES use?
The Kohler 8.5 RES uses a Kohler 2F4 alternator.
Troubleshooting
59Fault codes
| Code | Meaning | Cause | Remedy |
|---|---|---|---|
| AF | Input from a customer-supplied switch that closes when the fault is active. The generator set shuts down and will not start when the fault is active (input is grounded). | Check the cause of the auxiliary fault. | |
| HE | Shutdown occurs if the engine coolant temperature exceeds the maximum temperature for more than 5 seconds. This protective becomes active after the engine reaches the crank disconnect speed. | Check for blocked air inlets and exhaust outlets. | |
| LOP | Shutdown occurs if a low oil pressure condition exists 7 seconds after the engine has reached crank disconnect speed. | Note: The low oil pressure shutdown does not protect against low oil level. Check the oil level at the engine. Check for leaks in the lubrication system. | Check the oil level and add oil if the level is low. |
| OC | Shutdown occurs after 3 unsuccessful starting attempts. The crank cycle is set for three starting attempts of 15 seconds cranking and 15 seconds rest. The generator set also shuts down after 1 crank attempt if no speed signal is sensed. Shuts down 1 second after the fault is detected. | Check the fuel supply, spark plug, and battery. Check for loose connections. | Contact an authorized distributor/dealer for service if problem continues. |
| OF | Shutdown occurs when the governed frequency exceeds 110% of the system’s frequency setpoint for more than 1 second. This protective becomes active 30 seconds after engine start. | Contact an authorized distributor/dealer for service if problem continues. | |
| OS | Shutdown occurs if the engine speed exceeds 115% of the normal running speed for more than 1 second. | Contact an authorized distributor/dealer for service if problem continues. | |
| OU | Shutdown occurs if the voltage exceeds 120% of the voltage regulator setpoint for more than 1 second. | Contact an authorized distributor/dealer for service if problem continues. | |
| UF | Shutdown occurs when the governed frequency falls 1 Hz below the system’s frequency setpoint for more than 1 second. | Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service if problem continues. | |
| UU | Shutdown occurs if the voltage falls below 80% of the voltage regulator setpoint for more than 1 second. This protective becomes active 30 seconds after engine start. | Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service if problem continues. | |
| HB | Fault code is displayed if the engine starting battery voltage rises above 16 VDC for a 12 VDC system or above 30 VDC for a 24 VDC system for more than 10 seconds when the engine is not running. This fault condition does not inhibit engine starting. | Check the battery rating and condition. Check the battery charger operation. | |
| LB | Fault code is displayed if the engine starting battery voltage falls below 8 VDC for a 12 VDC system or below 16 VDC for a 24 VDC system for more than 10 seconds when the engine is not running. This fault condition does not inhibit engine starting. | Check the battery rating and condition. Check the battery charger operation. | Charge or replace the battery. |
| AF | Indicates a shutdown initiated by pushing the emergency stop switch. | Not used on RES models. | Check the position of the emergency stop button. (TRES models only) |
| HE | High engine temperature shutdown | Shutdown occurs if the engine coolant temperature exceeds the maximum temperature for more than 5 seconds. This function becomes active after the engine reaches the crank disconnect speed. | Check for blocked air inlets and exhaust outlets. |
| LOP | Low oil pressure shutdown | Shutdown occurs if a low oil pressure condition exists for more than 5 seconds. This function becomes active 30 seconds after the engine has reached crank disconnect speed (30 second inhibit). Note: The low oil pressure shutdown does not protect against low oil level. Check the oil level at the engine. | Check for leaks in the lubrication system. Check the oil level and add oil if the level is low. |
| OC | Overcrank shutdown | Shutdown occurs after 3 unsuccessful starting attempts. The crank cycle is set for three starting attempts of 15 seconds cranking and 15 seconds rest. | Check the fuel supply, spark plug, and battery. Check for loose connections. Contact an authorized distributor/dealer for service if problem continues. |
| Locked rotor | The generator set also shuts down on OC if no engine rotation is sensed during cranking. Shuts down 3 seconds after the fault is detected. | ||
| OF | Overfrequency shutdown | Shutdown occurs when the governed frequency exceeds 110% of the system’s frequency setpoint for more than 5 seconds. This function becomes active 10 seconds after engine start (10 second inhibit). | Contact an authorized distributor/dealer for service if problem continues. |
| OS | Overspeed shutdown | Shutdown occurs if the engine speed exceeds 110% of the normal running speed for more than 0.3 seconds. | Contact an authorized distributor/dealer for service if problem continues. |
| OU | Overvoltage shutdown | Shutdown occurs if the voltage exceeds 120% of the system nominal voltage for more than 2 seconds. | Contact an authorized distributor/dealer for service if problem continues. |
| UF | Underfrequency shutdown | Shutdown occurs if the governed frequency falls below 54 Hz for more than 5 seconds. Shutdown also occurs if the governed frequency falls below 56.5 Hz for more than 60 seconds. This function becomes active 10 seconds after engine start. (10 second inhibit). | Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service if problem continues. |
| UU | Undervoltage shutdown | Shutdown occurs if the voltage falls below 80% of the nominal system voltage for more than 10 seconds. | Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service if problem continues. |
| HB | High battery voltage warning | Fault code is displayed if the engine starting battery voltage rises above 16 VDC for more than 30 seconds when the engine is running. Not operative during the engine crank cycle, this fault condition does not inhibit engine starting. | Check the battery rating and condition. Check the battery charger operation. |
| LB | Low battery voltage warning | Fault code is displayed if the engine starting battery voltage falls below 11 VDC for more than 30 seconds when the engine is not running. Not operative during the engine crank cycle, this fault condition does not inhibit engine starting. |
Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| Battery short circuits. | Disconnect the battery before generator set installation or maintenance. Remove all jewelry before servicing the equipment. Use tools with insulated handles. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery. Never connect the negative (--) battery cable to the positive (+) connection terminal of the starter solenoid. Do not test the battery condition by shorting the terminals together. | |
| Accidental starting | Disconnect the battery cables before working on the generator set. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery. | |
| Battery short circuits | Disconnect the battery before generator set installation or maintenance. Remove all jewelry before servicing the equipment. Use tools with insulated handles. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery. Never connect the negative (--) battery cable to the positive (+) connection terminal of the starter solenoid. Do not test the battery condition by shorting the terminals together. | |
| Fuse blows repeatedly | Replace Auxiliary winding fuse (F1). Contact an authorized distributor/dealer if the fuse blows again. | |
| Generator set master switch in the OFF/RESET position | Move generator set master switch to the AUTO or RUN position. | |
| Red LED stays on for more than 24 hours | One or more defective or damaged cells. | Load test the battery and replace, if necessary. |
| Red and green LEDs stay on for more than 24 hours | Onboard DC systems are drawing between 1.5 and 5 amps. | Turn off all DC equipment while charging. |
| Neither of the LEDs turn on | No AC power available at the battery charger. | Connect AC power or reset the AC breaker on the main panel. |
| Green LED stays on when the battery is known to be low | One or more defective or damaged cells. | Load test the battery and replace, if necessary. |
| The generator set does not crank. | Battery weak or dead, Battery charger fuse blown, Battery connections reversed or poor, Controller fuse (F3) blown, Relay interface board fuse (F2) blown | Check power to the battery charger. Recharge or replace the battery. Replace the fuse. Contact an authorized distributor/dealer for service if fuse blows repeatedly. Check the connections. Replace the fuse. Contact an authorized distributor/dealer for service if fuse blows repeatedly. |
| Generator set does not crank | Weak or dead battery | Recharge or replace battery. If battery is weak or dead, check battery charger fuse, power supply, and operation. |
| Generator set cranks but does not start | No fuel | Open (turn on) manual fuel valve. Check fuel supply tank (LP). |
| Stops suddenly | Fault shutdown | Check for a fault shutdown code on the controller’s LED display. Correct the fault and then move the generator set master switch to OFF/RESET to reset the controller. |
| No fuel | Turn on fuel supply. | |
| Engine overheated | Check air intake, fuel adjustment, oil level, air inlet/outlet. | |
| Low oil pressure (LOP) switch | Attempt startup. If unit shuts down, remove lead from LOP switch and reset controller. A successful restart attempt indicates a faulty LOP shutdown switch. Note: Check engine oil pressure before performing test and/or replacing LOP shutdown switch. | |
| Fuel valve/fuel regulator | Check regulator/valve operation. | |
| Engine overloaded | Reduce electrical load. | |
| Lacks power | Air intake restriction, inadequate cooling. Inspect air intakes and exhaust for obstructions. Check air cleaner. | |
| Generator overloaded | Reduce load. | |
| Engine not running at rated rpm | Check controller settings for unit configuration (UC) and engine type (EC). Adjust governor speed. | |
| Engine power loss | Refer to the Engine Service Manual for troubleshooting and repair instructions. | |
| Governor malfunction or misadjustment | Test/readjust governor. | |
| Low output voltage | Incorrect controller configuration, Incorrect controller voltage settings | Check and adjust the controller configuration parameters. Check and adjust the controller voltage settings. |
| Alternator or control system problem | Perform separate excitation procedure to isolate the problem to the alternator or the control system. Then troubleshoot the alternator or control system components as follows. | |
| No output voltage | AC output circuit breaker open, Alternator or control system problem | Check for AC voltage on the generator side of circuit breaker. If there is AC voltage on the generator side of the breaker, then a problem in the load circuits is causing the line circuit breaker to trip. Check for and correct short circuits or overloading on the load side before resetting the circuit breaker. Perform separate excitation procedure to isolate the problem to the alternator or the control system. Then troubleshoot the alternator or control system components as follows. |
| Open wiring, terminal, or pin in buildup circuit or SCR module circuit | Check continuity. | |
| Brushes problem | Inspect brushes and replace if worn. Check for brushes sticking in brush holder or broken brush spring. | |
| Rotor connections problem | Check for open circuit in rotor connection circuit (leads FN and FP to SCR and RIB). | |
| Rotor slip rings dirty or corroded | Check slip ring condition. | |
| Stator problem | Check voltage and continuity. | |
| Engine not running smoothly | See “Generator set operates erratically,” this table | |
| Broken or damaged vibromount(s) | Check and replace as necessary. | |
| Loose or vibrating sheet metal/housing | Retighten screws, replace rivets. | |
| Exhaust piping or air inlets/outlets not securely installed | Inspect for loose parts and secure if necessary. | |
| Excessive engine/generator vibration | Check, rotor, crankshaft, bearing, etc. (disassembly of engine and/or alternator may be required). |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Parts
25| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 12 050 01-S | Filter, oil | 40 | Filter | PartsGeek kuduparts $32.00 |
| 12 132 02-S | Spark plug | 2 | Spark plug | PartsGeek |
| 24 050 01-S | Filter, breather | 8 | Filter | PartsGeek |
| 24 083 08-S | Element, air filter | 1 | Air filter | PartsGeek |
| 24 083 09-S | Element, air filter | 1 | Air filter | PartsGeek |
| 241927 | Kit, speed sensor | 1 | Sensor | PartsGeek |
| 25 132 14-S | Spark plug (RFI) | 2 | Spark plug | PartsGeek |
| 269373 | Alternator Assembly | 5 | Alternator | PartsGeek |
| 53AB | 6 Amp Automatic Battery Charger R C US LISTED | 1 | Battery charger | PartsGeek |
| 586536 | Foam precleaner | 1 | Pre-cleaner | PartsGeek |
| ADV-6823-A | Air Filter, Spark Plug Location | 1 | Air filter | PartsGeek |
| BKR-8YU11 | Spark Plug, CH20/CH740 | 4 | Spark plug | eBay PartsGeek |
| GM28823 | Sensor, temperature (oil) | 1 | Sensor | PartsGeek |
| GM29253-GA1 | Controller Wiring Diagram | 1 | Controller wiring diagram | PartsGeek |
| GM66010 | Emergency stop switch | 1 | Emergency stop switch | PartsGeek |
| 223316 | Relay interface board, Controller, Battery charger (RES) | 5 | Service part / kit | PartsGeek |
| 24 083 02-S | Pre-cleaner | 8 | Service part / kit | PartsGeek |
| 24 083 05-S | Pre-cleaner | 8 | Service part / kit | PartsGeek |
| 292937 | Fuse, 20 A, 250 V | 5 | Service part / kit | PartsGeek |
| 358337 | Controller F3 | 1 | Service part / kit | PartsGeek |
| 745-020-B0-003 | Enclosure Grounding Stud | Service part / kit | PartsGeek | |
| F-228605 | Kit, voltage regulator | 1 | Service part / kit | PartsGeek |
| GM10064 | PCB assembly (relay controller) | 1 | Service part / kit | PartsGeek |
| GM29671 | PCB assy, relay board 12V | 1 | Service part / kit | PartsGeek |
| GM62345-SKP1-QS | Service part / kit | PartsGeek |
Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.
Fuel consumption
| Rating | Load | L/h | gal/h |
|---|---|---|---|
| 25% | 77.0 | ||
| 50% | 93.0 | ||
| 75% | 113.0 | ||
| 100% | 132.0 | ||
| Prime | |||
| Prime | 25% | ||
| Prime | 50% | ||
| Prime | 60% | ||
| Prime | 75% | ||
| Prime | 100% | ||
| Standby | |||
| Standby | 25% | ||
| Standby | 50% | ||
| Standby | 60% | ||
| Standby | 75% | ||
| Standby | 100% |
Available documents
Brochure (Kohler)Spec sheet — 12RES (Kohler)Spec sheet — 85-12-kw-Kohler-Residential-Generator (Kohler)Spec sheet — Spec Sheet Res (Kohler)Spec sheet — g4097 (Kohler)Installation manual — g18118 (Kohler)Installation manual — tp6328 (Kohler)Installation manual — tp6514 (Kohler)Installation manual — tp6792 (Kohler)Installation manual — tt1364 (Kohler)Installation manual — tt1445 (Kohler)Installation manual — tt1486 (Kohler)Reference (Kohler)Reference — g18146 (Kohler)Reference — g260823 (Kohler)Reference — g6127 (Kohler)Reference — g6129 (Kohler)Reference — tp6264 (Kohler)Reference — tp6766 (Kohler)Reference — tp6766cmp (Kohler)Reference — tp7004 (Kohler)Owner's manual — tp6331 (Kohler)Owner's manual — tp6515 (Kohler)Parts manual (Kohler)Service manual — 12 RES Operation (Kohler)Service manual — 8.5 12 RES Service (Kohler)Service manual — Kohler.Maintenance.Kits.g6131Service manual — Operation Installation Res (Kohler)Service manual — tp6196 (Kohler)