Every barn we work on is the tallest metal-roofed thing in a quarter-square-mile.

Why farms need this and most don't have it

A 60-foot-tall dairy barn with a metal roof, sitting alone in a 40-acre hayfield, is a textbook lightning attractor. The strike doesn't have to be direct: a strike to a maple a hundred feet away will induce a 6 kV transient on the milking-parlor electrical, and that transient — without a surge protective device on the front of the panel — will pass through every contactor, every PLC, and every bulk-tank refrigeration controller on the property.

Most farms in our service area do not have an NFPA 780 lightning-protection system (LPS). They do, increasingly, have a Type-1 surge protective device at the service entrance, because we have made it standard inclusion on every J-01 service-upgrade since 2023. The two systems are complementary: the LPS protects the structure from a direct or near-direct strike; the SPD protects the electronics from the transient that gets through.

What we install

NFPA 780 lightning protection system

• Air terminals on roof ridges and high points. Spacing per NFPA 780 table 4.6.1.4: 20 ft for buildings under 75 ft, 25 ft above. Nickel-plated copper, 24" minimum, threaded base.
• Main-conductor network (down-conductors): bare #1/0 stranded copper, secured to the structure every 3 ft, no sharp bends, two paths per air terminal.
• Ground rings: counterpoise loops of bare #1/0 buried 30 in below grade, encircling the structure, tied to two driven rods per gable.
• Bonding to electrical service: at the meter base or main panel, the LPS ground network is bonded to the electrical grounding electrode system per NFPA 780 chapter 4.14.
• Bonding to interior metal systems: gas piping, water service, milk-transfer pipe, sap-line vacuum tubing if metallic.
• UL Master Label or LPI Inspection Certificate. We are Lightning Protection Institute-listed installers.

Type-1 SPD at the service entrance

• Mounted on the line side of the main breaker; 10 kA per mode minimum, tested to UL 1449 4th edition.
• Indicator visible without opening the panel.
• Replaceable on its own; the SPD is a sacrificial component and we expect it to wear out before the panel does.
• Standard inclusion since 2023 on every J-01 service.

Type-2 SPDs at sub-panels and equipment panels

• Mounted at the milking-parlor sub-panel, the sugarhouse sub-panel, the dwelling-house sub-panel, and at any sensitive-equipment panel.
• Coordinated with the Type-1 above.

What it costs

Scope	Typical low	Typical median	Typical high
Type-1 SPD added to existing service	$420	$680	$1,200
SPD at every sub-panel (small farm)	$1,400	$2,400	$3,800
NFPA 780 LPS, single barn	$5,800	$9,500	$15,000
NFPA 780 LPS, full farm (house + barn + sugarhouse)	$14,000	$22,500	$34,000

What insurance pays for

Most Vermont farm insurance policies will discount the premium 8–14% on a property with a UL Master Labeled or LPI-certified LPS. Farm Bureau Insurance, Co-operative Insurance Companies (Vermont), and American Family all do; the discount typically pays back the LPS install cost over 7–11 years. Bring the certificate to your agent at the next renewal.

What we don't do

• Wind-turbine lightning protection (the manufacturer handles this in their kit; we do the building-side bonding only).
• Telecommunications-only surge protection (cable, fiber, antenna). We coordinate with the carrier; their gear, our bonding.
• Any LPS that is not NFPA 780 conformant. Older "tradition" systems from the 1950s sometimes look the part and we'll inspect them, but we won't certify or warrant them.

Related

The almanac entry on summer storm patterns is October: Shoulder-season inspections, which has more on the post-summer LPS condition check.