Specifications include, but are not limited to: UT Southwestern Medical Centers Building K was originally designed and constructed in the late 1970s. The electrical distribution system for this facility is located in the basement. Bus ducts from the existing switchboards distribute electrical power to the five floors and penthouse of the building through a vertical chase. Steam leaks in the basement areas and crawl space have caused water damage in several of the bus ducts. This project will replace these bus ducts with conduit and wire. Preliminary load data suggests these circuits are carrying less load than originally designed. In an effort to reduce cost and space, bus ducts will be replaced with lower ampacity cable and conduit given an official determination of circuit load shows compliance with NFPA 70. Accordingly, the associated feeder circuit breakers will be reconditioned and retrofitted with new sensors and ratings to comply with NFPA 70 for protection of the lower ampacity cables. Determine Existing Loads i. Determine maximum demand on each circuit being replaced in accordance with NFPA 70. Proposed feeder loads shall be verified to be in accordance with NFPA 70 prior to commencing construction. b. Bus Duct Replacements i. Emergency Life Safety Bus Duct (HE1) 1. Replace existing HE1 feeder from emergency distribution panel (BE) to the second floor utility chase with two (2) sets of (4C-300kcmil, 3 EMT). 2. Connect HE1 feeder to existing HE1 vertical busway at second floor utility chase with 600A Square D I-Line busway fusible plug-in unit, Catalog No. PBQ4660G, from Schneider Electric. 3. Recondition and retrofit circuit breaker with new sensors and ratings to comply with NFPA 70 and all local codes and ordinances. ii. General Power Distribution Bus Duct (GDP) 1. Replace existing GDP busway from the GDP distribution panel to the first floor electrical room with two (2) sets of (4C-300kcmil, 3 EMT). 2. Replace existing cable and conduit from GDP circuit breaker to GDP distribution panel with two (2) sets of (4C- 600kcmil, 4 EMT) 3. Replace the GDP feeder 1200A Fuses in GDP distribution panel with 600A fuses. 4. Connect GDP feeder at first floor electrical room with a 600A Square D I-Line busway fusible plug-in unit, Catalog No. PBQ4660G, from Schneider Electric. 5. Recondition and retrofit circuit breaker with new sensors and ratings to comply with NFPA 70 and all local codes and ordinances. iii. HVAC Systems Bus Duct (MCC) 1. Replace existing MCC feeder from the 480V main switchboard to the motor control centers in the penthouse with two separate circuits, one circuit feeding each MCC. Both circuits will consist of two (2) sets of (3C-300kcmil, 3 EMT). 2. Make connections at each MCC directly 3. Recondition and retrofit MCC circuit breaker with new sensors and ratings to comply with NFPA 70 and all local codes and ordinances for feeding one MCC. 4. Recondition and retrofit spare circuit breaker with new sensors and ratings to comply with NFPA 70 and all local codes and ordinances for feeding the other MCC. iv. Building Lighting Bus Duct (HL1) 1. Ground floor transformer, Panel C, and Panel FI-GH1 are currently fed from tap boxes on HL1 in the first floor electrical room. These circuits will be transferred to the GDP distribution panel in the basement. a. Feeder Panel C i. Demolish existing busway plug in and cable conduit to Panel C. ii. Install 4C-#2,1.5C from existing/owner provided 100A circuit breaker in GDP distribution panel panelboard in basement to Panel C b. Feeder Panel FI-GH1 i. Demolish existing busway plug in and cable conduit to Panel GHI. ii. Install 4C-3/0,2.5C from existing/owner provided 200A circuit breaker in GDP distribution panel panelboard in basement to Panel GH1
