Generac GP5500 generators are reliable machines, but when they've been sitting unused for an extended period, issues can arise. It's good that you've already replaced the brushes and the Automatic Voltage Regulator (AVR). Since the generator sat unused for four years, there could be a few more issues to check:
- Stator and Rotor Inspection: The stator and rotor are essential components of the generator's alternator system. Over time, rust or corrosion can develop on these parts. Carefully inspect them for any signs of damage or rust. Clean them if necessary.
- Excitation Circuit: Ensure the excitation circuit is working correctly. This circuit is responsible for providing the initial voltage to the alternator when the generator starts. Check the wiring and connections associated with the excitation circuit.
- Field Windings: Inspect the field windings for any damage. These are coils of wire responsible for generating the magnetic field necessary for electricity generation.
- Capacitor: Check the capacitor for signs of damage or leakage. The capacitor can affect the voltage output of the generator.
- Wiring and Connections: Examine all the wiring and connections carefully. Loose or corroded connections can result in low voltage output. Make sure all wires are properly connected and in good condition.
- Voltage Regulator Adjustment: After replacing the AVR, it's essential to ensure that it's adjusted correctly. Consult the generator's manual for specific instructions on adjusting the AVR to achieve the desired voltage output.
- Output Voltage Setting: Some Generac generators allow you to adjust the output voltage. Check the manual to see if there's a voltage adjustment knob or screw.
- Load Testing: Once you've checked and potentially fixed these issues, perform a load test. Connect a load to the generator and see if the voltage output increases as the load increases. This will help determine if the generator is producing enough power for your needs.