The Nexus is a generator-set controller. It is used on generator sets from Generac and Nexus, including the Guardian Series Air-Cooled 10 kW unit, Guardian Series Air-Cooled 14 kW unit, Guardian Series Air-Cooled 17 kW unit and Guardian Series Air-Cooled 20 kW unit.
Used across brands: Generac, Nexus
Also fitted to: Generac 005873-1, Generac 005875-1, Generac 005885-1, Generac 005886-1, Generac 005887-1, Generac 006053-0 (17 kW), Generac 006053-1, Generac 10 kW, Generac 6 kW, Generac 8-20 kW, Nexus CntrlNexus001.
| Code | Meaning | Cause | Remedy |
|---|---|---|---|
| 0 | Utility failure | Crank and start engine, transfer load to Generator if Utility returns above 75% nominal for 15 seconds | |
| 000001 | DANGER | ||
| 1100 | Condition - Engine Cranks but will not Start (5 crank attempts) | Unit turns over but will not start. Controller is receiving signal on Wire 18. | Problem 17 |
| 1200 | Prolonged (60 Hz on a 50 Hz unit, 72Hz on 60Hz unit) Overspeed | Overspeed for 3 seconds. Possible cause: Stepper motor/mixer body assembly issue. | Test 12 |
| 1205 | Instantaneous (62 Hz on a 50 Hz unit, 75Hz on 60Hz unit) Overspeed | Overspeed for 0.1 second (100 milliseconds). Possible cause: Stepper motor/mixer body assembly issue. | Test 12 |
| 1300 | Occurred while running | Check oil level and pressure. Test 61 | |
| 1400 | Condition - Air Flow Impeded / Flow Issue | Check the inlet/outlet for debris. Check temperature sensor and wiring. Test 62 | |
| 1501 | RPM Sensor ALARM | ||
| 1501 | Twin Cylinder+Running | Twin Cylinder Running faults to RPM Sensor Loss. Possible Causes: air pocket in fuel line, dirty fuel, missing ignition pulse (loss of one of the primary coils). | Test 50 and Test 64 |
| 1505 | Twin Cylinder+Cranking | Twin Cylinder Cranking faults to RPM sensor loss Possible Cause: starter motor issue, missing ignition pulse (loss of one of the primary coils). If engine cranks, Test 64. If engine does not crank, Problem 15. | |
| 1511 | Single Cylinder+Running | Single Cylinder Running RPM sensor loss Possible Causes: air pocket in fuel line, dirty fuel. Loss of ignition pulse. | Test 50 and Test 64 |
| 1515 | Single Cylinder+Cranking | Single Cylinder Cranking faults to RPM sensor loss Possible Causes: starter motor issue, missing ignition pulse (loss of one of the primary coils). If engine cranks, Test 64. If engine does not crank, Problem 15. | |
| 1900 | Prolonged Over-Voltage Undervoltage | ||
| 1901 | Instantaneous Undervoltage | ||
| 1902 | Undervoltage | ||
| 2099 | Wiring Error ALARM | ||
| 2100 | Stepper Overcurrent ALARM | ||
| 2102 | Overloaded ALARM | ||
| 2399 | Overload Remove Load ALARM | ||
| Battery is Dead | Problem 22 – Battery is Dead | Test 45 – Check Battery and Cables | |
| Evolution E-Code 2400 | Engine Will Not Crank When Utility Power Source Fails | Test 44 – Check 7.5 Amp Fuse Evolution Alarm Code 2400 | |
| Evolution Fault codes 1900 - 1906 | Generator Shuts Down for Under Voltage | ||
| Generator Will Not Exercise | Problem 20 – Generator Will Not Exercise | Test 45 – Check Battery and Cables | |
| No Low Speed Exercise | Problem 21 – No Low Speed Exercise | ||
| Problem 18 | Shutdown Alarm/Fault Occurred |
| Symptom | Cause | Remedy |
|---|---|---|
| Generator Shuts Down for Over Voltage | ||
| Generator Shuts Down for Overload / Over Voltage | ||
| AUTO/OFF/MANUAL Switch at OFF, engine continues to run. | 1. Defective AUTO/OFF/MANUAL switch 2. Defective Control Module circuit board | 1. Replace board.* 2. Replace board.* |
| Engine cranks but will not start | No fuel. | Replenish fuel / turn on fuel shutoff valve. |
| Engine cranks but won't start. | 1. Out of fuel. 2. Fuel solenoid (FS) is defective. 3. Spark plugs defective. | 1. Replenish fuel/turn on fuel valve. 2. Replace solenoid.* 3. Clean, regap or replace plugs. |
| Engine damage. | Verify proper type and quantity of engine oil prior to starting engine. Failure to do so could result in engine damage. | |
| Engine speed and frequency drop excessively under load | Engine may be underpowered; result of dirty air cleaner, loss of engine compression, faulty fuel settings, or incorrect ignition timing | Refer to Section 4.5 Diagnostic Tests for repair procedures |
| Engine starts hard and runs rough | Plugged or damaged air cleaner. | Inspect and clean or replace air cleaner. |
| Engine starts hard, runs rough. | 1. Air cleaner plugged or damaged. 2. Defective spark plugs. 3. Fuel pressure incorrect. 4. Insufficient fuel supply. 5. Fuel system set to wrong fuel type. | 1. Clean or replace as needed. 2. Clean, regap or replace plugs. 3. Confirm fuel pressure to regulator is as recommended in SPECIFICATIONS.* 4. Confirm fuel pressure to regualtor is as recommended in SPECIFICATIONS.* 5. Reconfigure the fuel system. (See RECONFIGURING THE FUEL SYSTEM in manual.*) |
| Engine starts then shuts down. | 1. Engine oil level is low. 2. Engine is overheated. 3. Defective Low Oil Pressure Switch 4. Defective Coolant Temperature Switch 5. Defective Control Module circuit board. 6. Coolant Level is Low. 7. Defective Low Coolant Level Switch. | 1. Check oil and add oil as needed. 2. Check cooling system for leaks. 3. Replace switch.* 4. Replace switch.* 5. Replace board.* 6. Repair leak - Add coolant. 7. Replace Switch.* |
| Engine will not crank | Blown fuse. | Correct short circuit condition by replacing 7.5A fuse in generator control panel. Contact an IASD if fuse continues to blow. |
| Engine won’t crank. | 1. Control panel 7.5 amp fuse blown. 2. Loose or corroded or defective battery cables. 3. Defective starter contactor. 4. Defective starter motor. 5. Dead or Defective Battery. | 1. Replace fuse.* 2. Tighten, clean or replace battery cables as necessary.* 3. Replace contactor.* 4. Replace starter motor.* 5. Remove, change or replace battery.* |
| Generator Produces High Voltage | TEST 1 - CHECK AC OUTPUT VOLTAGE, HIGH -> TEST 11 - CHECK AC OUTPUT FREQUENCY, HIGH -> TEST 12 - CHECK STEPPER MOTOR CONTROL, REFER TO PROBLEM 1, TEST 3 - CALIBRATE VOLTAGE, VOLTAGE OUTPUT AT BREAKER IS BELOW 220 OR ABOVE 270 VOLTS -> VOLTAGE OUTPUT AT BREAKER IS BETWEEN 220-270 VAC -> FREQUENCY O.K., BUT VOLTAGE INCORRECT -> FREQUENCY AND VOLTAGE O.K. -> STOP TESTS | |
| Generator Produces High Voltage at No-Load | TEST 14 - CHECK AC OUTPUT FREQUENCY TEST 16 - CHECK STEPPER MOTOR CONTROL TEST 2 - CHECK AC OUTPUT VOLTAGE | |
| Generator Produces Low Voltage at No-Load | TEST 14 - CHECK AC OUTPUT FREQUENCY TEST 16 - CHECK STEPPER MOTOR CONTROL TEST 2 - CHECK AC OUTPUT VOLTAGE | |
| Generator Produces Zero Voltage or Residual Voltage | TEST 1 - CHECK MAIN CIRCUIT BREAKER TEST 4 - PERFORM FIXED EXCITATION / ROTOR AMP DRAW PERFORM STATOR INSULATION RESISTANCE TEST - SECTION 1.4 PERFORM ROTOR INSULATION RESISTANCE TEST - SECTION 1.4 TEST 7 - TEST STATOR TEST 5 - WIRE CONTINUITY TEST 6 - FIELD BOOST TEST 11 - CHECK ROTOR RESISTANCE CHECK VOM FUSES TEST 12 - CHECK BRUSHES & SLIP RINGS TEST 13 - TEST ROTOR ASSEMBLY REPAIR OR REPLACE FUSES | |
| Generator Shuts Down for Under Voltage | Perform FBCT, Preliminary Output Voltage Test (if Evolution non-Synergy with Firmware v1.12 or higher), TEST 4 - Fixed Excitation / Rotor Amp Draw, RE-TEST, REPLACE CONTROLLER if necessary, CHECK DMM FUSES, TEST 5 - SENSING CIRCUIT WIRES 11 AND 44, BAD -> TEST 6 - EXCITATION WINDING CIRCUIT 2 AND 6, BAD -> TEST 8 - RESISTANCE CHECK OF ROTOR CIRCUIT, GOOD -> TEST 7 - TEST STATOR, BAD -> PERFORM STATOR INSULATION RESISTANCE, REPLACE STATOR ONLY if necessary, TEST 10 - TEST ROTOR ASSEMBLY, BAD -> REPLACE ROTOR AND STATOR, BAD -> REPAIR OR REPLACE, BAD -> ROTOR CIRCUIT FAILURE, TEST 9 - CHECK BRUSHES & SLIP RINGS, GOOD -> BAD -> TEST 10 - TEST ROTOR ASSEMBLY, GOOD -> TEST 7 - TEST STATOR, BAD -> REPLACE ROTOR ONLY, BAD -> REPLACE ROTOR AND STATOR, PERFORM ROTOR INSULATION RESISTANCE TEST | |
| High Temperature ALARM | Check the inlet/outlet for debris. Check temperature sensor and wiring. | |
| Low Oil Pressure ALARM | Occurred while running The default Extended alarm for low oil pressure. Check oil level and pressure. | |
| NOT ACTIVATED! | Press ESC and then ENTER to reset Install Wizard. | |
| No AC output from generator | Generator MLCB (generator disconnect) is OFF (OPEN). Generator internal failure. | Set generator MLCB (generator disconnect) to ON (CLOSED). Contact an IASD for assistance. |
| No AC output from generator. | 1. Main line circuit breaker is tripped/open. 2. Generator internal failure. 3. Thermal circuit breaker open. | 1. Reset to ON/CLOSED. 2. * 3. Auto-reset - Wait 5 min. and attempt restart. *Contact the nearest Dealer for assistance. |
| No transfer to standby after utility source failure | Generator MLCB (generator disconnect) is OFF (OPEN). | Set generator MLCB (generator disconnect) to ON (CLOSED). |
| Overspeed ALARM | Prolonged (60 Hz on a 50 Hz unit, 72Hz on 60Hz unit) Over specified Hz for 3 seconds. Possible cause: Stepper motor/mixer body assembly issue. | |
| Unit consumes large amounts of oil | Excessive engine oil. | Adjust oil to correct level. See checking engine oil level section in owner’s manual. |
| Unit is set to OFF, but engine continues to run | Controller wired incorrectly. | Contact an IASD for assistance. |
| Unstable Voltage or Incorrect Output Which is Not Triggering a Shutdown | TEST 1 - CHECK AC OUTPUT VOLTAGE, ERRATIC -> PROCEED TO PROBLEM 3 | |
| Voltage and Frequency Drop Excessively When Loads Are Applied | TEST 14 - CHECK VOLTAGE AND FREQUENCY UNDER LOAD, BOTH LOW -> TEST 15 - CHECK FOR OVERLOAD CONDITION, NOT OVERLOADED -> GOOD -> IF RECONFIGURED TO LP GAS, VERIFY THAT PROPER PROCEDURE WAS FOLLOWED (REFER TO INSTALLATION MANUAL), GOOD -> OVERLOADED -> DISCONTINUE TESTING, REDUCE LOADS TO UNIT’S RATED CAPACITY, TEST 12 - CHECK STEPPER MOTOR CONTROL, GOOD -> BAD -> REPAIR OR REPLACE, LOOK FOR A SHORTED CONDITION IN A CONNECTED LOAD OR IN ONE OF THE LOAD CIRCUITS, GOOD -> TEST 7 - CHECK STATOR AC POWER WINDINGS, ENGINE CONDITION GOOD -> REPAIR OR REPLACE, BAD -> TEST 16 - CHECK ENGINE CONDITION, GOOD -> GO TO “PROBLEM 18 - ENGINE STARTS HARD AND RUNS ROUGH/LACKS POWER” SECTION 4.3 | |
| Wi-Fi network connection broken or intermittent | Various. | See Wi-Fi module owner’s manual. |
Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.