Yes — if you're running AC mains power (like 120V or 240V) into a metal enclosure, grounding is absolutely required. This is a basic safety rule that helps protect against electric shock and potential fire hazards if a short circuit occurs. Often, the electrical enclosure will perform as usual with incorrect grounding, though will result in a danger. Since I will have some SMA connectors mounted to the metal enclosure, if I do not insulate these connectors from the metal enclosure of the clock, they will connect the metal enclosure to CLOCK GROUND. Grounding gives stray current a safe path to follow. Grounding and bonding are the basis upon which safety and power quality are built. The grounding system provides a low-impedance path for fault current and limits the voltage rise on the normally non-current-carrying metallic components of the electrical distribution system.
