Addendum 001_Scope Clarification.pdf

Replace Main Electrical Distribution

Project No. 596A4-24-101

Lexington VAMC

Addendum 001

The construction phasing strategy has been developed to maintain the highest level of electrical system reliability while minimizing outages and disruptions to facility operations throughout construction. The overall intent is to complete the installation of new infrastructure to the greatest extent possible prior to scheduling outages, demolition of existing equipment, or modifications to the existing electrical distribution system. The Contractor shall develop and submit a comprehensive, detailed phasing plan and project schedule identifying all construction activities, outage durations, temporary installations, testing, and commissioning procedures within phasing for review and approval by the VA prior to the commencement of work.

The Contractor shall be required to ensure that hospital operations are maintained and are required to provide temporary connections and/or temporary power throughout construction to ensure minimal outages and disruptions to operations. The Contractor shall sequence construction activities to maintain two independent and reliable sources of electrical power to the affected distribution system at all times. The Contractor shall provide all temporary equipment, connections, feeders, switching, controls, and operational measures necessary to maintain continuous facility operations, preserve system redundancy, and minimize outages throughout the duration of construction.

The Contractor shall be responsible for final equipment layouts based on the selected manufacturer's equipment and shall provide dimensioned shop drawings demonstrating compliance with all required working clearances. A minimum clearance of three (3) feet shall be maintained behind the Tower Switchgear unless greater clearances are required by the equipment manufacturer. All cable lengths, routing, terminations, and installation methods shall be the responsibility of the Contractor and shall be coordinated with the final equipment configuration.

Construction activities shall be sequenced to maintain emergency electrical service throughout the project.

Emergency power to the fire pump controller shall remain operational at all times, and the required on-site emergency fuel capacity shall be maintained for the duration of construction. Primary electrical infrastructure work shall be completed prior to modifications affecting the network protector system whenever practical to reduce operational risk.

To minimize outages during replacement of the Tower Switchgear two temporary sources shall be installed and fully operational prior to demolition of the existing switchgear to maintain facility operations during the replacement period, one generator will serve as a backup. The Contractor shall be responsible for providing, operating, maintaining, fueling, and monitoring the temporary generator system throughout the duration of the temporary installation.

The outage required to transition the Tower Switchgear out of service and restore building service is anticipated to be limited to approximately eight (8) hours; however, the Contractor shall verify the required outage duration as part of the detailed outage plan. Prior to any outage, the Contractor shall verify that all downstream low-voltage emergency distribution systems are fully operational and capable of supporting facility operations. At the time of construction, the facility is anticipated to be operating on standby power, and all work shall be coordinated accordingly.

Following establishment of temporary power, the existing Tower Switchgear shall be removed and replaced with the new switchgear. New medium-voltage feeders shall be installed from the Main Switchgear, followed by construction of the transformer feeder connections sequentially serving Transformers T-1 through T-4.

Upon completion of installation, the Contractor shall perform all required testing, commissioning, protective device testing, and functional verification of the new switchgear before sequentially transferring each transformer through planned outages to complete the permanent feeder connections. After successful commissioning and acceptance of the permanent installation, the temporary generator system shall be removed and the existing four-way switch demolished.

Replacement of the network protectors shall be coordinated with the equipment manufacturer to safely isolate each associated unit during construction. The Contractor shall provide detailed shop drawings documenting the proposed replacement sequence and shall provide all temporary structural supports necessary to maintain the integrity of the existing busway during network protector replacement. Upon completion of the work, the Contractor shall restore the busway to its fully operational condition, maintaining all applicable UL listings and manufacturer requirements. Planned outages associated with network protector replacement shall be coordinated with the VA, and temporary power shall be provided by the Contractor as necessary to maintain service to critical facility loads. Contractor shall ensure operations are maintained and provide temporary connections/power to maintain operations. Contractor shall be responsible to provide all materials and connections for associated temporary power requirements.

Replacement of the existing Emergency, Critical and Life Safety Automatic Transfer Switches shall be accomplished using temporary transfer switches. The temporary ATS equipment, associated feeders, and all required electrical connections shall be completely installed, tested, and operational prior to demolition of the existing transfer switches. The Contractor shall coordinate all outages with the VA and minimize outage durations to the greatest extent practicable while maintaining continuous emergency power to critical facility systems.

Where modifications are made to UL-listed electrical equipment or assemblies, the Contractor shall coordinate all required inspections, certifications, and approvals necessary to maintain or reinstate the applicable UL listings. Any modifications required to restore equipment listing following installation shall be included within the Contractor's scope of work.

As part of the overall project, modifications to the transformer room door swing shall also be completed to provide the required access and working clearances for installation, operation, and maintenance of the new Tower Switchgear. All construction activities shall be coordinated to maintain safe access, required electrical clearances, and uninterrupted facility operations to the greatest extent practicable throughout the duration of the project.