High specification Capacitor.
Generator Guru says:
It is common for the capacitor on a generator to test as working correctly, but then fail when the higher voltages are applied to it by the alternator. It is advisable to always change your Generator Capacitor if the voltage changes (and the engine is normal speed.) This causes 99% of the problems with the electricity output on brushless generators and can damage your alternator if it completely fails, sending a high voltage through the alternator. This could burn out the windings and result in a very expensive replacement being required.
The Capacitor is essential to your Generator producing electricity. It is required to excite the Alternator windings and reduce voltage surges. Capacitors should last the lifetime of the generator, but can burn out or be damaged if any of the following occur:
- Generator user has tried to draw more power than the Generator can produce.
- A surge has happened on equipment and the capacitor has blown to protect the Alternator.
- The Capacitor is made of Paper cells and has degraded. (Usually found on Chinese built generators.)
See our video below on testing procedure.