Hospital meets critical power needs

Phoenix Children's Hospital's emergency power supply system must meet emergency standby requirements for both a healthcare facility and a high-rise building.

By Shawn Grimm, PE, ccrd partners September 15, 2011

Phoenix Children’s Hospital in Phoenix is both a healthcare facility and a high-rise building. As such, the facility’s emergency power supply system (EPSS) must meet emergency standby requirements for both types of facilities. To meet these requirements the facility has a remote central energy plant housing most of its EPSS. The emergency power supply (EPS) consists of three 2 MW generators and medium-voltage paralleling gear and distribution. Unit substations are located throughout the facility with automatic transfer switches (ATS) located downstream of unit substation. Any of the three 2 MW generators can accommodate the requirements of NFPA 70 and NFPA 99 for the life safety branch and critical branch for the entire facility. There are also a variety of stored emergency power supply systems (SEPPSS).

The EPSS serves all of the required fire protection and life safety systems including voice communications, fire detection and alarm system, electric fire pump, emergency fire command center, exit signs, means of egress illumination, power operated doors, and mechanical stair shaft ventilation systems for smoke-proof enclosures. The EPSS also serves all other functions required under NFPA 70 Article 517.

There are a variety of SEPSS battery systems used throughout the facility. There is a central inverter to provided egress lighting in the main lobby, emergency battery ballast used in rooms where patients are anesthetized, and a centralized UPS for the data center.

Multiple system tests were performed to ensure that each of the required systems would operate correctly when different events occurred. A variety of different test were conducted including power outages, remote power transfer on ATS from the command center, smoke detector activation, pull station activation, duct detectors activation, and fire pump test to ensure the proper system function.

Grimm is associate principal and project manager with ccrd partners in the Phoenix office. He is the lead electrical engineer, and leads the electrical design of different projects including hospitals, institutional facilities, and office buildings.