SC pipe enters the distribution box and grounds

The SC pipe should be grounded using an equipment grounding conductor connected to the distribution box's dedicated ground bar, ensuring a low-resistance path to the main grounding system. Steps for Proper Grounding1. Use the Correct Grounding Conductor: Attach a properly sized equipment grounding conductor (EGC) from the SC pipe to the distribution box's ground bar.

In the U

S, a 10 AWG wire is typically required, while in other markets a 6 mm² conductor may be used. The conductor must be continuous and free of splices unless using listed connectors. 2.

Connect to the Ground Bar: Inside the distribution box, the SC pipe should be bonded to the dedicated ground bar using a listed mechanical connector, such as a set-screw or crimp connector. Ensure the connection is tight and corrosion-resistant. 3.

Bond the Ground Bar to the Main Grounding System: The ground bar in the distribution box must be connected to the building's main grounding electrode system or central grounding point. This ensures that any fault current is safely directed to earth. 4.

Maintain Low Resistance: The total resistance from the SC pipe to the main grounding system should be very low, ideally below 0. 1 ohm for industrial applications. If multiple rods or conductors are needed, connect them in parallel to achieve the required resistance.

5. Verify Compliance and Safety: Test the grounding system with a suitable meter to confirm continuity and resistance. Ensure all metal parts of the distribution box, including the SC pipe, are at earth potential to prevent shock hazards.

Avoid relying on accidental grounding through supports or conduit connections, as this may result in high-resistance paths and unsafe conditions. 6.

Follow NE

C and Local Codes: All connections should comply with NEC Article 250 and local electrical codes. Never connect the SC pipe directly to a grounding electrode without an EGC, and always use listed connectors for bonding.

Practical Tips

Use corrosion-resistant materials for connectors and conductors. Avoid double-tapping neutrals on the ground bar. Keep wiring neat and organized to facilitate inspection and maintenance.

If the S

C pipe is long or serves multiple circuits, consider using a larger conductor to maintain low resistance. By following these steps, the SC pipe entering the distribution box will be safely grounded, protecting both personnel and equipment from electrical faults.