DCCC – Electrical Switchgear Replacement

As the prime firm/engineer-of-record, Gipe Associates coordinated with architectural and mechanical subs for the replacement of the 15kV campus primary distribution equipment at the college. This included the 15kV metal-clad switchgear and two double-ended secondary substations. Redundancy was built into the system at the 15kV switchgear, configured in a main-tie-main arrangement with A and B split bus, as well as in the substations, each fed radially from the A and B busses. The substations were sized so that one transformer could accommodate the entire load. This equipment, and associated feeders, was installed with the construction of the building in the mid-1960’s. The 15kV switchgear and one double-ended substation were located in the middle of the basement, off the main mechanical room in Founder’s Hall. The other substation was located in a mechanical room in the center of the first floor in Academic Hall. These buildings were adjacent to each other, with the 15kV feeders routed in cable tray through a utility tunnel. Two buildings were constructed on campus in the interim and were both were fed via a single radial feed from the 15kV switchgear.

The owner’s preferred design was a radial distribution system to match how the newer buildings on campus were fed. The construction was phased to minimize the outages and a new 15kV primary selective fused metal-enclosed load interrupter switchgear was installed. The switchgear was located near the utility tunnel entrance, with sufficient feeders for the phased replacement and provisions for expansion. The existing 15kV feeders were then re-fed from this location, and the existing metal-clad switchgear was removed. Two unit substations were installed in the newly vacated space and the feeders from the existing substation were cut over to the new switchboard sections.

This project included extensive detailed fieldwork and field measurements. All physical obstructions, including items and equipment that needed to be relocated and reinstalled in order to accommodate the replacement equipment were identified and included in the scope of work. The replacement equipment design included precise dimensional requirements that were coordinated during design and verified during the shop drawing review phase and in construction.

Other Project Highlights Include:

• Feasibility study and cost analysis comparison
• Life cycle cost analysis that included the transformer efficiency
• Preliminary design prepared to minimize service disruptions during equipment replacement

Project Type: Higher Education,