Troubleshooting/es

Los sistemas FV autónomos son sistemas complejos con muchos componentes diferentes que deben funcionar juntos perfectamente para que el sistema pueda proporcionar energía a los usuarios finales. Un problema en el diseño del sistema, la instalación o la fabricación de componentes normalmente no se hará evidente hasta que el sistema comience a funcionar mal. A menudo, con sistemas FV autónomos, se identifica fácilmente un error, como un sistema de almacenamiento de energía agotado en un sistema que se instaló 5 años antes. Otras veces puede ser bastante complicado identificar qué está causando el problema porque un problema solo puede ocurrir de manera intermitente bajo ciertas condiciones exactas que deben identificarse o un problema puede manifestarse en un componente, como el inversor que se apaga, pero en realidad es el resultado de un sistema de almacenamiento de energía con una tensión baja porque la fuente FV no está funcionando correctamente. Es importante comprender todos los diferentes componentes y considerar cómo interactúan como un sistema para realizar correctamente un proceso de solución de problemas. La complejidad de un sistema FV autónomo y el hecho de que sea un sistema que funciona con electricidad significa que cualquier enfoque para identificar y resolver un problema debe realizarse de forma sistemática y con precaución. Un sistema que tiene un problema no identificado debe tratarse con precaución adicional ya que el sistema tiene un componente defectuoso, un error de instalación o una falla a tierra, que puede crear varios peligros imprevistos.

1. Ask questions of anyone who has been using the system: When did the issue start? What was the weather like around that time? How was the system being used when the issue first appeared - time of day? what lights/appliances were on? Had any changes been made to the system or had the way in which the system is used changed like a new appliance or adding a new circuit? Was the battery bank depth of discharge (DoD) staying within appropriate guidelines recently?
2. Before touching any part of the system, perform a visual inspection: Does everything look like it is properly connected and installed? Does anything appear burnt or smell strange? Has electrolyte spilled out of flooded lead acid batteries? Are any error or warning lights blinking on the equipment?
3. Any system that is undergoing troubleshooting should follow safety guidelines and best practices outlined in Electrical safety. All people in the vicinity should be notified that you are beginning to work on the system and all power sources should be locked out and tagged out.
4. Use a multimeter properly. When taking any measurements or evaluating any part of the system, it is vital to ask beforehand: what would be expected if the system were functioning properly? Compare the result that your result and consider carefully if the two vary.
5. Methodically examine the system. Check different combinations of components and circuits. Disconnect particular circuits. Check components in isolation. Write down your results if it is a particularly complex system. This will help narrow down the component or circuit that is causing the issue.
6. It is often necessary when troubleshooting to energize (turn on) certain parts of a system in order to be able to check voltages and if they are functioning properly in isolation. This should be done very carefully and only by someone who has sufficient knowledge and understanding of off-grid PV systems.

Example of a system with a ground fault

Example 1: See example image. The inverter for a system shut down unexpectedly. No overcurrent protection devices were activated. Every time the inverter is turned back on, it shuts down immediately. The inverter does not have a read-out screen to assist with error identification. How would you troubleshoot this system?

1. Question system users. The response is that nothing has been out of the ordinary, that the system simply stopped functioning one evening.
2. Visually inspect the system. There are no apparent issues.
3. Notify everyone in the area of the need to troubleshoot the system. Properly secure all power sources.
4. Check battery bank voltage. It is a 24V system, therefore it should be above 23V if the system is functioning properly. Measured voltage is 25V. A low voltage battery bank is not likely to be the issue. This also means that the PV source and charge controller are likely functioning properly. The problem likely is with the inverter or circuits connected to the inverter.
5. Disconnect all AC circuits from the inverter and attempt to turn it on. It works properly.
6. 220V AC output is anticipated from the inverter and that is what is measured.
7. Turn off the inverter and reconnect one circuit. Turn the inverter back on one the circuit is reconnect. It works properly.
8. Turn off the inverter and reconnect a second circuit. Turn the inverter back on after the circuit is reconnected. The inverter turns off immediately. This circuit has some type of problem.
9. Ensure the inverter is disconnected and that all Power source disconnects are open (turned off).
10. Visually inspect the circuit that has issues. A rodent has chewed through the wire and created a ground fault that caused the inverter to have an error before the overcurrent protection devices identified an issue.
11. Replace the damaged wire and test the system. The problem has been resolved.