As part of a substation upgrade to replace aging infrastructure, M&S Engineering provided design, material procurement, and project management for Phase 1 to replace a 100 MVA 138 kV to 36 kV distribution transformer and associated metal-clad switchgear. In addition, to minimize the risk of service interruptions to the San Antonio International Airport, the existing 138 kV bus was split into two buses with the addition of a 138 kV tie breaker. Relay upgrades and additional relaying was required to protect the 138 kV bus. For Phase 2 of this project, M&S performed upgrades to the existing 138 kV 50 MVAR capacitor bank, which included upgraded relays with the addition of a 138 kV IPO breaker. Finally, in Phase 3, M&S was tasked with upgrading relaying on the 138 kV bus #1 diﬀerential relaying along with relay upgrades to Transformer #2 and Switchgear #2.
Cory Kaladcek, P.E.
Spring Branch, TX