Lightning Protection Systems Training

1. Lightning Protection Systems Training Section 5 Concealed and Structural Systems Presented by

2. Systems Training Outline

3. Section 5A

4. Concealed Systems • When concealed, conductors are permitted to be installed under roof framing.

5. Concealed Systems • When concealed, conductors can also be installed under roof materials.

6. Concealed Systems • Conductors can also be installed behind exterior wall facing or between wall studs.

7. Concealed Systems • Conductors can be installed in conduit or copper conductors can be imbedded directly in concrete or masonry construction.

8. Concealed Systems • If the lightning conductor is run in metal conduit, it must be bonded to the conduit at both ends and at any point where the conduit is not electrically continuous.

9. Concealed Systems • In masonry chimneys, both air terminal bases and lightning protection conductors can be concealed within the chimney or attached to the exterior and routed through the structure to concealed main conductors.

10. Concealed Systems • Lightning conductors and all other lightning protection components concealed in steel reinforced concrete must be connected to the reinforcing steel at both the upper and lower extremities.

11. Concealed Systems • Long vertical reinforcing steel members must have additional connections to the lightning conductor at intervals not exceeding 200’ • Horizontal lightning conductor runs must be connected to the reinforcing steel at intervals not exceeding 100’

12. Concealed Systems • Grounding electrodes for concealed systems follow the same rules discussed previously in the ground work section. • Grounding electrodes located under basement slabs or in crawl spaces need to be installed as close as possible to the outer perimeter of the structure.

13. Concealed Systems • Where ground rods are used, they must be in contact with the earth for a minimum of 8’ and extend to a depth of not less than 10’ below finished grade, except as permitted by the requirements for shallow soil.

14. Section 5B

15. Structural Steel Systems • The structural steel framework of a structure can be utilized as a main lightning conductor if it is electrically continuous.

16. Structural Steel Systems • Strike termination devices can be mounted directly on the structural steel framing.

17. Structural Steel Systems • Individual conductors routed through the roof or parapet walls can also be connected to the structural steel. • When external lightning conductor is used, it must be connected to the structural steel at intervals not exceeding 100 ft.

18. Structural Steel Systems • Lightning conductor can be connected to the structural steel which has been cleaned to bare metal mechanically or by welding or brazing.

19. Structural Steel Systems • When using mechanical connections the bonding plate must have a surface area of at least 8 sq. inches. Bonding plates must have bolt-pressure cable connectors and can be bolted, brazed or welded to the steel column.

20. Structural Steel Systems • When rust-protective paint has been removed from the steel column, the base steel must be protected with a conductive corrosion-inhibiting coating.

21. Structural Steel Systems • Drilling and tapping structural steel to install is an acceptable method as long as the air terminal has at least 5 full threads fully engaged and is secured with a jamb nut.

22. Structural Steel Systems • When the structural steel is utilized as the down conductor, grounding electrodes must be connected to approximately every other steel column around the perimeter of the structure at intervals averaging not more than 60 ft.

23. Summary • End of Section 5