Yia | Contract Alerts

All contracts › Wyoming

Z2DA--666-27-102 Lightning Protection Update B71N

Description

GENERAL: Introduction: An inspection for current code compliance of the lightning Protection System on Building 71N has been conducted and found the system needs upgrades and repairs to meet current NFPA 780 and UL96A standards. The Sheridan VA Medical Center needs the services of a qualified contractor to perform the needed lightning protection upgrades to the main hospital building 71N. Located on the Sheridan Wyoming Veterans Affairs Medical Center (VAMC) campus, at 1898 Fort Road, Sheridan, Wyoming 82801. Statement of Work: Specifics a. Existing Conditions The existing lightning protection system (LPS) for Building 71N was installed in 1989 during the building s original construction. Overall, the system remains in fair condition, though it requires repair because several air terminals have become detached from their adhesive bonds to the roof surface. Air terminals are present at all high points of the structure, and all roof-mounted equipment and appurtenances are properly grounded. A main grounding bus connects the communication systems and possibly the electrical distribution system to the primary service ground. The specific location where the grounding system bonds together the structural steel, electrical system, lightning protection components, and plumbing to create an equipotential ground could not be identified during the assessment. A continuous grounding loop encircles Buildings 9, 71, and 71N, with all roof air terminals and down conductors tied into this loop. Down conductors descend to the loop at the corners of each of these buildings. Each air terminal has at least two separate grounding paths, satisfying current code requirements. No Transient Voltage Surge Suppression (TVSS) devices were observed in the system. The lower 8 feet of the ground down conductors are encased in PVC electrical conduit for protection. New Construction Recent construction has added large equipment and a screen wall to the roof, which now obstructs and interferes with the original positioning of the existing air terminals. This new equipment sits higher than the existing lightning protection system components, rendering the current air terminals ineffective at intercepting and safely directing lightning strikes to ground. Project Requirements To bring the existing lightning protection system (LPS) into compliance the following corrections are needed: Install Transient Voltage Surge Suppression (TVSS) devices at the building s main service panel. Establish proper bonding by interconnecting all electrical systems, communication systems, piping, and structural steel at the service entrance to create an equipotential ground. Repair all roof air terminals that have detached or pulled away from their adhesive mounts on the roof surface. Install new air terminals at both ends of each screen wall, with additional terminals spaced at 20-foot intervals along the top of each wall, and at the highest point of the HVAC ductwork. Install an air terminal at each c…