Lightning Protection

[hhsting]

In NEC 2017 Article 250.106 doesn’t say which table to use to size bonding jumper to lighting protection system between grounding electrode system? I looked didnt see anyone know where it is?

 

[augie47]

Conductor size for lightning protection are covered in NFPA 780

 

[hhsting]

Conductor size for lightning protection are covered in NFPA 780

Inclding the bonding jumper that bonds lighting protection to building grounding electrode system and its size? That doesnt fall under NEC?

 

[augie47]

Inclding the bonding jumper that bonds lighting protection to building grounding electrode system and its size? That doesnt fall under NEC?

That is my understanding, yes, NFPA 780

 

[infinity]

You can try this right from the NEC:

250.4(A) Grounded Systems.
250.4(A)(1) Electrical System Grounding.
Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation.

Informational Note No. 1: An important consideration for limiting the imposed voltage is the routing of bonding and grounding electrode conductors so that they are not any longer than necessary to complete the connection without disturbing the permanent parts of the installation and so that unnecessary bends and loops are avoided.

Informational Note No. 2: See NFPA 780-2017, Standard for the Installation of Lightning Protection Systems, for information on installation of grounding and bonding for lightning protection systems.

250.106 Lightning Protection Systems.
The lightning protection system ground terminals shall be bonded to the building or structure grounding electrode system.
Informational Note No. 1: See 250.60 for use of strike termination devices. For further information, see NFPA 780-2017, Standard for the Installation of Lightning Protection Systems, which contains detailed
information on grounding, bonding, and sideflash distance from lightning protection systems.