Code Change Summary: A new code section was added in part X of Article 250 to address grounding and bonding of fences and other metal structures related to substations.

Section 250.194 is new in Part X of Article 250 and covers the grounding and bonding requirements for metal structures and fences near a substation. Most substations are utility owned and therefore not covered in the NEC^® but once in a while, a substation is privately owned and the NEC^® applies.

The new code section requires fencing to be bonded to the grounding electrode system if the fencing is within 16 ft. of any exposed electrical conductors or equipment. For these fences, a wire type bonding jumper is required as follows:

• Bonding jumpers are required at each fence corner and at maximum 160 ft. intervals along the fence.
• Bonding jumpers are required on each side of the crossing where bare overhead conductors cross the fence.
• Gates must be bonded to the gate support post, and each gate support post must be bonded to the grounding electrode system.
• Any gate or other opening in the fence must be bonded across the opening by a buried bonding jumper.
• The grounding grid or grounding electrode systems shall be extended to cover the swing of all gates.
• The barbed wire strands above the fence must be bonded to the grounding electrode system.

Below is a preview of the NEC^®.  See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).