Grounding wire of power supply box and distribution box for suspended platform

Proper grounding of power supply and distribution boxes ensures safety, prevents electrical faults, and requires correctly sized copper conductors connected to designated grounding points.

Grounding Requirements

Each distribution box and power supply unit must be grounded to the factory or central grounding system.

For U

S installations, a 10 AWG (5. 26 mm²) ground wire is typically used, while in other markets, a 6 mm² wire is standard. The grounding system must maintain a resistance of less than 0.

1 Ohm between all connected components to ensure effective fault current dissipation.

Connection Method

Locate the Grounding Point: Open the distribution box and identify the PE bar or grounding plate marked for grounding connections. Connect the Power Ground Wire: Use a yellow-green insulated copper wire with a cross-sectional area meeting or exceeding the specified size. Strip the wire, insert it into the terminal, and tighten securely with a screwdriver.

Ground Electrical Components: Any internal components requiring grounding should be connected to the PE bar using copper wires to ensure safe operation. Mounting Plate Bonding: For suspended platforms with tool cables or spindles, an additional ground wire may be run from the mounting plate to the spindle plate to reduce total resistance, especially for long cable runs.

Conductor Sizing and Safety

Ground conductors must be sized to carry fault currents sufficient to trip protective devices. Minimum sizes are 14 AWG for copper and 12 AWG for aluminum, with larger sizes required for higher currents. For long tool cables, a 16 mm² copper wire (or 6 AWG in the US) may be used between mounting and spindle plates to maintain low resistance and ensure proper grounding.

All terminals must be rated to accept the conductor size used.

Precautions

Ensure all connections are firm, clearly marked, and free of looseness for inspection and maintenance. Use listed connectors such as twist-on wire nuts, tool-crimped connectors, or mechanical set-screw connectors to comply with NEC and UL standards. Verify grounding resistance after installation to confirm it meets the