Grounding wiring of distribution box

The grounding box in a distribution box should be connected to the PE bus, the metal enclosure, and all components requiring grounding using properly sized copper wires to ensure safety and compliance.Steps for Proper Grounding1. Locate the Grounding Bar (PE Bus): Open the distribution box and identify the grounding bar, often marked as "PE" or with a grounding symbol. This bar serves as the central point for all grounding connections within the box . 2. Connect the Power Ground Wire: Use a yellow-green insulated copper wire with a cross-sectional area meeting local electrical standards (typically ≥6 mm² outside the US, or 10 AWG in the US). Strip the wire, insert it into the PE bar terminal, and tighten the screw securely to ensure a firm connection . 3. Ground the Metal Enclosure: The metal casing of the distribution box must be electrically connected to the PE bus. This can be done using a copper wire or braided copper tape connected to a dedicated grounding bolt on the box. For stainless steel enclosures, apply conductive grease to prevent corrosion and maintain low contact resistance . 4. Ground Internal Components: Any electrical components inside the box that require grounding should be connected to the PE bus using copper wires. This ensures that all exposed conductive parts are safely grounded . 5. Connect Conduit and External Metal Parts: Metal conduits or threaded pipes entering the box should also be bonded to the box's grounding system, either by welding or using conductive connectors, to maintain a continuous grounding path . 6. Verify Grounding Effectiveness: After wiring, measure the resistance between the enclosure and the main grounding electrode. The resistance should be very low (typically