The distribution box needs to be repeatedly grounded

Yes, each distribution box must be grounded individually and connected to a central grounding system to ensure safety and proper operation.Importance of Repeated GroundingGrounding each distribution box is essential for personnel safety, equipment protection, and system stability. Proper grounding channels fault currents safely into the earth, reducing the risk of electric shock and protecting equipment from overvoltages, lightning strikes, and transient conditions . It also stabilizes voltage levels across the system, ensuring protective devices like circuit breakers operate correctly .Recommended Grounding PracticesIndividual Ground Connections: Each distribution box should have a dedicated ground wire connected from a threaded stud or grounding point on the box to a mounting plate or directly to the central grounding system . This ensures that even if one connection fails, other boxes remain safely grounded.Wire Sizing: In the US, a 10 AWG (5.26 mm²) ground wire is recommended, while in other markets a 6 mm² wire is standard . For connections between mounting plates and equipment like spindles, larger wires (e.g., 6 AWG or 13.29 mm²) may be used to maintain low resistance.Ground Resistance: The total resistance between all system parts should be less than 0.1 Ohm to ensure effective fault current flow . Parallel grounding paths, such as combining tool cable and dedicated ground wires, help achieve this low resistance.Bonding: All metallic components, enclosures, and raceways should be bonded into a continuous conductive system to maintain equal potential and prevent dangerous voltage differences .Central Grounding Point: Each box's ground wire should ultimately connect to a factory or central grounding point, creating a unified grounding network that enhances safety and system reliability .SummaryRepeated grounding of each distribution box is not optional; it is a critical safety and operational requirement. Properly sized conductors, low-resistance connections, and bonding to a central grounding system ensure that fault currents are safely dissipated, equipment is protected, and personnel are safeguarded from electrical hazards .