Final answer:
Functional earthing in a PV array system is used for electrical stability and maintaining the reference voltage. Protective earthing provides a safe path for fault currents to protect people and equipment from electric shocks. Diagrammatically, a PV system would show the protective earth connected to frames and casings, and the functional earth as the reference for system operation.
Step-by-step explanation:
Difference Between Functional Earthing and Protective Earthing in a PV Array System
The primary difference between functional earthing and protective earthing in a photovoltaic (PV) array system is their respective purposes within the electrical safety and operation of the system.
Functional earthing, also known as grounding, is used in a PV array for electrical stability. It helps in the proper functioning of the PV system by stabilizing the voltage levels and minimizing the interference from external electrical noise. This earthing is usually connected to the negative or the positive of the DC side of the power system and helps to maintain the reference voltage for the system operations.
Protective earthing, on the other hand, is designed to protect people and equipment from electrical faults. It provides a low-resistance path to Earth for fault currents, which ensures that any exposed conductive parts do not reach a dangerous voltage level. This includes components like the metallic frames of PV panels and the inverters. If a fault occurs, such as insulation failure, the fault current is directed safely to the earth, reducing the risk of electric shock.
A pictorial representation would include a PV array connected to an inverter, with a protective earth linking the metallic frames and casings to a grounding point, while the functional earth creates a reference point for the system operation.