Bonding Requirements for Multifamily Dwelling Service with TroughBonding the Trough Bonding material

Solid copper, brass, or aluminum

Bonding conductor

#6 AWG minimum

Connection

The bonding conductor must be securely connected to the trough using a listed clamp or bolt.

Location

The bonding connection should be made as close to the water service entrance as possible.

Grounding the Bonding Conductor Grounding electrode system

The bonding conductor must be connected to the multifamily dwelling's grounding electrode system (GES).

GES requirements

The GES must comply with Article 250 of the National Electrical Code (NEC). It should typically consist of: Ground rods driven into the earth Water pipes Metal underground gas piping

Connection

The bonding conductor should be connected to the GES at a point where it is protected from physical damage.

Additional Bonding Requirements Metallic cold water pipes

All metallic cold water pipes that enter or are connected to the dwelling must be bonded to the trough.

Other conductive materials

Any other conductive materials that are in contact with the trough or the metallic cold water pipes should also be bonded.

Inspection The bonding system should be inspected regularly to ensure proper continuity and integrity.

References National Electrical Code (NEC), Article 250* Uniform Plumbing Code (UPC), Chapter 6 Flag for review