What type of equipment grounding conductor must be used for electric signs or outline lighting systems?

For electric signs or outline lighting systems, using a wire type equipment grounding conductor is essential due to safety and performance requirements. Wire type conductors provide a reliable and robust means of grounding, which is crucial for preventing electrical faults and ensuring the proper functioning of the sign or lighting system.

A wire type equipment grounding conductor can be installed effectively within the system, providing a low-resistance path for fault current to safely dissipate. This helps to reduce the risk of electric shock, fire, and equipment damage, particularly in outdoor settings where electric signs and lighting are often used.

The other options, such as metal type or flexible type, may not adhere to regulatory standards specific to electric signs, as they may not provide the necessary level of protection or compliance with codes. Furthermore, stating that no grounding is required is incorrect because grounding is a critical safety measure in preventing hazards associated with electrical equipment.