Short Circuit Coordination Study for VA Palo Alto Health Care System
Short Circuit Coordination Study for VA Palo Alto Health Care System
Client: VA Palo Alto HCS
Location: Palo Alto, CA
Key personnel for this project included John Lopez, PE, Neil Sherer, EIT, Donald Crawford, and Wesley Breckenridge. They performed an Arc Flash Study at the VA Palo Alto Health Care System in Palo Alto, CA. This study analyzed and evaluated the 12.47 kV electrical distribution system for the VA Palo Alto Health Care System facilities. Existing drawings for the electrical system were reviewed; electrical system components were visited and observed by an electrical subcontractor (Global Power, Inc.) with equipment and training to open and observe 15 kV rated equipment. VA maintenance personnel familiar with the electrical system were interviewed along with SKM software used to perform short circuit and arc flash calculations.
Global Power, Inc, accompanied by VA Electricians, surveyed the existing 12 kV distribution system. They gathered the existing electrical drawings, opened all transformers and gathered nameplate data for all electrical equipment, including individual relays, feeder conductor sizes and circuit lengths, as well as photographed existing equipment. LEI used this gathered field data to developed single line diagrams and modeled the system in SKM. Analysis of single line diagrams for hazards was performed and a short circuit study was prepared. Arc Flash labels were prepared and delivered to Global Power to install on electrical equipment.
A follow up overcurrent coordination study was also performed to coordinate the substation main circuit breaker and feeder breaker relay settings with the City of Palo Alto substation circuit breaker relay settings.