⚡ NFPA 780 Section 4.21 (Sideflash Clearance Distance D = [h/6n] x [Ki/Km])

Lightning Sideflash Clearance Calculator

Calculate mandatory physical separation and equipotential bonding distances to prevent dangerous high-voltage sideflash arcing between lightning downconductors and internal building metal piping/electrical conduits under NFPA 780 Section 4.21: calculate required clearance (D based on bonding height h, downconductor count n, and insulation media Ki/Km), and LPS engineering margins.

1. Project & Operating Inputs

Downconductor Paths Installed (Conductor Count e.g. 8 Downconductors)

Structure Height Above Ground (Feet e.g. 120 ft High Structure)

Customer Bid Price for Supplied, Routed & Bonded Downconductors ($)

Heavy Copper Cable, Ground Test Wells, Exothermic Welds & Techs ($)

2. Financial Breakdown & Yield

NFPA 780 SIDEFLASH BONDING

Turnkey LPS Equipotential Bonding Profit

Electrical Protection Margin

0.0%

Gross Revenue / Bill

Total Project CapEx

Operating / Material Cost