Substation 4 Replacement at the University of Pennsylvania

Substation 4 is a critical piece of infrastructure serving the University of Pennsylvania’s electrical system. Originally located in the lower level of an existing building, the substation had aged beyond its useful life and required full replacement. Trefz was engaged to design and support the installation of a modernized system that would meet the university’s operational and safety standards.

The Scope

The existing Substation 4, located in the lower level of an aging building, had reached the end of its useful life and required a full replacement to improve safety, reliability, and maintainability. The new design called for 15kV switchgear equipped with a PLC-based automatic control system, Human-Machine Interface (HMI), and a redundant hot-standby system to ensure continuous operation.

The Process

Trefz designed and implemented a phased transition strategy to maintain uninterrupted power to the University of Pennsylvania campus throughout construction. The existing substation remained operational while the new substation was installed, tested, and energized. Trefz coordinated the process so that both systems could operate in parallel, allowing campus feeders to be relocated one at a time. This careful sequencing ensured that no buildings were left vulnerable to a single point of failure and that critical systems remained online. Once all loads had been safely transferred, the old substation was de-energized and removed, along with the original PECO services.
Schweitzer protective relays were installed on all main, tie, and feeder breakers to detect faults and isolate issues before they could impact the wider system. A differential protection system was added for the switchgear bus, with two independent zones to protect each section separately. Additionally, sync check relays were included on the mains and tie circuit breakers to ensure safe and proper synchronization during source transitions, as this was essential during the live transfer of electrical loads. Trefz also oversaw the installation of the power factor correction capacitors, transformers, and ductbanks, ensuring each component was delivered and integrated according to the project’s tight phasing and safety requirements.

The Result

The new Substation 4 significantly upgraded the university’s electrical infrastructure. It enhances reliability, safety, and monitoring while minimizing disruption to campus operations. The phased transition and careful planning ensured that the new substation met the university’s long-term energy needs.

Let’s Collaborate

Trefz delivers innovative and reliable engineering solutions designed to meet the unique needs of every project. Whether modernizing critical infrastructure or enhancing system performance, we focus on delivering results that stand the test of time. Ready to take your project to the next level? Contact us today to get started.