The Stop is a generator-set controller. It is used on generator sets from Caterpillar, Cummins/Onan and MQ Power, including the C18 and DCA45USI.
Used across brands: Caterpillar, Cummins/Onan, MQ Power
Also fitted to: Cummins/Onan HDKAL/HDKAS.
| Symptom | Cause | Remedy |
|---|---|---|
| Damage to equipment and fire | Interconnections without an approved switching device | Use an approved switching device |
| Dizziness | Get out into the fresh air immediately. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. | |
| Engine does not crank. | Follow the troubleshooting procedure in Flow Chart A. | |
| Flame, cigarette, spark, pilot light, electrical arc-producing equipment and switches, or other sources of ignition near fuel fumes | Keep away from areas where fuel fumes are present | |
| Inability to Think Coherently | Get out into the fresh air immediately. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. | |
| Muscular Twitching | Get out into the fresh air immediately. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. | |
| NO AC OUTPUT VOLTAGE AT RATED ENGINE RPM | Load circuit breakers closed, circuit open between brush block and voltage regulator, brushes stuck in holder or not making good contact with slip rings, opens or grounds in rotor, stator, incorrect field voltage, broken wires or loose connections on voltage regulator assembly, engine running at correct RPM, adjustment of Voltage Adjust control on the regulator board results in correct output voltage, generator output leads improperly connected | Locate cause of overload and correct as required. Reset breaker, or replace if bad. Check continuity of circuit breakers and replace if necessary. Is circuit open between brush block and voltage regulator? If yes, check for continuity and correct if circuit is open. Are brushes stuck in holder or not making good contact with slip rings? If yes, release brushes if jammed in holder. Clean slip rings if dirty. Test continuity of rotor, stator per Tests [B], [C]. Are there opens or grounds? If yes, replace component if defective. Test field voltage per TEST [A]. Is there correct field voltage? If no, examine brush block connections. Are F1 and F2 leads installed on correct terminals? Perform TEST [D]. Connect brush leads to correct terminals. |
| Output voltage too high or too low | Remove part of the set load. Remove load at generator terminals. Are generator leads connected and grounded properly? See Test [C]. Is generator stator winding continuous per TEST [C]? Check load for ground faults and correct as necessary. Check for correct grounding of generator and load. Correct as necessary. Replace stator assembly. | |
| UNSTABLE OUTPUT VOLTAGE, ENGINE SPEED STABLE | Broken wires or loose connections on voltage regulator assembly, brushes stuck in holder or not making good contact with slip rings, engine running at correct RPM, adjustment of Voltage Adjust control on the regulator board results in correct output voltage, generator output leads improperly connected | Check wiring harness from regulator assembly to end bell per TEST [F]. Check OK? Repair as required. Inspect brushes per procedure in Manual Section 4. Brushes OK? Repair wiring or replace as required. Replace the voltage regulator per procedure [E]. Repair or replace as required. |
| Unbalanced generator output voltage | Remove load at generator terminals. Are generator leads connected and grounded properly? See Test [C]. Is generator stator winding continuous per TEST [C]? Check load for ground faults and correct as necessary. Check for correct grounding of generator and load. Correct as necessary. Replace stator assembly. | |
| Vomiting | Get out into the fresh air immediately. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. | |
| Weakness and Sleepiness | Get out into the fresh air immediately. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
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.