Critical Power: Backup power systems

Standby and emergency power systems provide power to ensure that life safety systems and critical equipment can operate during a power outage.

By CFE Media June 6, 2016

Design engineers have many factors to consider when designing a backup system for a facility. Safety, maintainability, code compliance, and economics play crucial roles in determining the topology of a backup system for a critical facility. Specific requirements for backup power vary based on building occupancy type, facility use, and critical function. When designing generator systems, for example, engineers must ensure that the generators and the building electrical systems that they support are appropriate for the specific application. They must make decisions regarding generator sizing, load types, whether generators should be paralleled, fuel storage, switching scenarios, and many other criteria.

Standby and emergency power systems provide power to ensure that life safety systems and critical equipment can operate during a power outage. NFPA 70: National Electrical Code (NEC) defines the categories that apply to generator power sources as emergency, legally required standby, optional standby, and critical operations power systems (COPS) systems. The differences among these systems are significant. In addition to the specific code requirements, design engineers as well as authorities having jurisdiction must know the effects these classifications have on how generators are applied within an electrical distribution system.

Due to the requirements of the NEC and NFPA 110: Standard for Emergency and Standby Power Systems, design engineers must carefully consider the implications of combining emergency, legally required, and optional standby systems to ensure code compliance with maintainability and economics in mind.

Learning Objectives:

  • Explain the applicable codes and standards: NFPA 70: National Electrical Code (NEC); NFPA 110: Standard for Emergency and Standby Power Systems; and other codes and standards as they apply to backup power systems.
  • Analyze and compare the differences and similarities among emergency, legally required standby, optional standby, and critical operations power systems (COPS) with a focus on backup systems.
  • Assess the effects each classification has on how generators are applied within an electrical distribution system to provide backup power.
  • Outline decisions regarding generator sizing, load types, whether generators should be paralleled, fuel storage, and switching scenarios.

Presenters:

Tom Divine, PE, senior electrical engineer and project manager, Smith Seckman Reid Inc., Houston

Douglas Lacy, PE, LEED AP, vice president, electrical engineer, WSP + ccrd, Dallas

Moderator: Jack Smith, Consulting-Specifying Engineer, Pure Power, and CFE Media, LLC


Author Bio: Since its founding in 2010, CFE Media and Technology has provided engineers in manufacturing, commercial and industrial buildings, and manufacturing control systems with the knowledge they need to improve their operational efficiency. CFE delivers the right information at the right time around the world through a variety of platforms.