Flexible Retail Center Design - Electrical Systems–

There are two main considerations to review when beginning the electrical portion of a retail shell design. The primary consideration is the Electrical Service design for the entire facility as well as the individual future tenants. While there are many lighting decisions to make which are primarily preference driven (parking lot lighting, accent lighting, etc.), the emergency/egress lighting is a code consideration which must be evaluated throughout the shell design phase.

In order to create as much flexibility as possible, the main service design will vary widely based on the building size. For larger centers, this may be accomplished through a package switchgear unit or for a variety of centers it might include a wireway with a series of disconnects and meters. As noted with other utilities, the main focus of this portion of the design should analyze the worst case usage. The equipment size is not always reflective of the worst case, but in order to maximize flexibility the secondary conduits from the transformer should always be provided based on the best analysis of the load for the entire facility. The primary difference is that while the package switchgear cost considerably more, in larger applications the space requirements can be significantly less than the wireway option.

Once the main service is designed, consideration must be given to conduit, wire, and panel distribution for the future tenant spaces. Should panels be installed in each space or should we just install conduits. If we decide to install conduit only, what size should we install. The answers to the questions will be based on the confidence the developer has in their knowledge of the future tenant types as well as the necessity to get tenants in the center quickly.

The least flexible tenant service design, although the quickest for future tenants, is to size the panels based on the intended use of the space and provide the meter, disconnect, and panel under the shell package. There are two other approaches which involve empty conduits for future spaces – these conduits can be run under the slab or to maximize flexibility they can be run overhead so as to allow conduits to easily be shortened or extended as tenants require. While not as flexible as the overhead conduits, the conduits underslab can be increased in size to add flexibility while not adding the same costs to the project as overhead metal conduit will. These same alternatives need to be considered for telephone/data conduits to each tenant.