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Arden Hills - City Hall Feasibility Study Electrical Narrative 4075-001-00 Part 4, Page 1 of 2 ELECTRICAL NARRATIVE Overview The building was designed and constructed in 2000, and presumed to have opened in 2001. The electrical service is original, 600 Amp, 120/208V 3 phase 4 wire wye. The service is adequately sized for the building, mechanical system, and usage, but has limited expansion capacity. There is no main disconnect or overcurrent device – the service uses the National Electrical Code (NEC) provision of the “six switch rule” and as such has no expansion capability, without adding a main device. In summary, the existing electrical system is in good condition. However, the incoming power service has no expansion capability in its current configuration. Any expansion would require a new enlarged three phase service. Electrical Service The existing service is a 600A underground service from and Xcel pad mounted transformer outside the southeast wall of the building at the main floor level, with underground primary from the south. The main electrical room is on the main floor level in the southeast corner of the building. This room also contains the MPOP and server/IT distribution equipment as well as radio equipment for EMS. There is an existing manual transfer switch in the main electrical room and four pin-and-sleeve connectors on the exterior wall for connection of a portable generator. The Xcel Energy pad mounted transformer is outside the southeast corner of the building, inside the screenwall for the dumpster, exterior mechanical cooling equipment, and the gas meter. Electrical service equipment is in good condition. The equipment has adequate clearance to the front and working space from side to side. There is no remaining space in the electrical room for additional panels or to install a main overcurrent/disconnect device to allow additional feeders for expansion. Branch circuit panelboards are located in the main electrical room only. The building is essentially as originally designed, with some lower level changes and fit-out of the “shell space” into offices and storage areas. The mechanical equipment consists of three AHU’s, boilers, recirculating pumps, exhaust fans, and sump pump located in the lower level mechanical room; cabinet unit heaters, unit heaters, and other miscellaneous small loads. Three DX condensing units are located outside in the screenwall area. Lighting Interior lighting is a mix of T-8 and compact fluorescent, LED, and incandescent, with exterior and site being mostly metal halide and LED. Site lighting includes parking lot, sign, pedestrian at entry, and minimal landscape lighting. There is no permanent generator for the building life safety or standby. There is limited battery pack egress lighting and battery pack exit signs. Telecommunications The building has a fiber optic service for phone and data connections. Fiber entrance is through the lower level with the equipment on the main level in the main electrical room with the electric service equipment. There is an equipment/control room for the council chambers that includes audio, visual, projection, voting, CCTV recording, and TV broadcast equipment.