Clarke RC90D troubleshooting: 12 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Clarke RC90D — full specs, parts & maintenance.
| Symptom | Cause | Remedy |
|---|---|---|
| Excessive overheating of one or both bearings (temp of bearings over 80°C) (With or without abnormal bearing noise) | If the bearing has turned blue or if the grease has turned black, change the bearing. | |
| Excessive overheating of alternator frame (temperature rise of more than 40°C above ambient) | Air flow (inlet-outlet) partially clogged or hot air is being recycled either from alternator or prime mover. Alternator is functioning at too high a voltage (over 105% of rated voltage on load). Alternator overloaded | |
| Too much vibration | Misalignment (coupling) Defective mounting or play in coupling Incorrect balancing of shaft (Engine-Alternator) | |
| No voltage at no load or startup | Connect a battery of 4 to 12 volts to terminals E+(F+) or E-(F-) respecting the polarity on the A.V.R for 2 to 3 seconds. The alternator builds up and voltage is correct when the battery is removed. | |
| Lack of residual magnetism in alternator | - Check the connections of the sensing leads to the A.V.R. - Faulty rotating diode - Short-circuit on rotor windings | |
| Voltage collapses during normal operation | Check the AVR, the surge suppressor, the rotating diodes and replace any defective part | |
| The output voltage does not return the rated value | Exciter winding open circuit Faulty exciter armature Faulty AVR Main field rotor winding open circuit or short circuit overload (See LED status) | |
| Voltage too low | Check the prime mover speed | |
| Incorrect speed | - Check A.V.R. connections (possible AVR failure) - Exciter field short-circuited - Rotating diode(s) burnt out. - Main field rotor short-circuited - Check the resistance. | |
| Voltage too high | Adjust potentiometer voltage | |
| No adjustment of voltage, measure voltage F+/F- on AVR | Voltage between F+ and F- > 12V or AVR faulty - One Faulty Diode | |
| Voltage oscillations | Adjust the stability potentiometer on A.V.R If no effect: change recovery mode normal/rapid. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: If the bearing has turned blue or if the grease has turned black, change the bearing.. See the table for the matching fixes.
Documented causes: Air flow (inlet-outlet) partially clogged or hot air is being recycled either from alternator or prime mover. Alternator is functioning at too high a voltage (over 105% of rated voltage on load). Alternator overloaded. See the table for the matching fixes.
Documented causes: Misalignment (coupling) Defective mounting or play in coupling Incorrect balancing of shaft (Engine-Alternator). See the table for the matching fixes.