All parts of a metal cable tray must be bonded together and?

Metal cable trays are used to support and route electrical wiring systems, providing both structural integrity and protection for the cables within. Bonding all parts of the metal cable tray ensures that they are at the same electrical potential, reducing the risk of electrical shock or fire hazards due to differences in voltage potential.

Grounding the cable tray is crucial because it provides a safe path for fault currents to dissipate. This is a critical safety measure that protects both the wiring system and personnel. By grounding the metal cable tray, any stray electrical currents that may inadvertently make their way into the tray can travel safely to the ground, rather than presenting a danger through equipment or individuals.

While options such as insulation, securing tightness, and painting can relate to different aspects of cable tray installation or maintenance, they do not address the essential need for electrical safety that grounding provides. Grounding effectively minimizes the risk of electrical shock and enhances the safety and reliability of the electrical installation. It is a foundational practice in electrical installations governed by codes and standards.