Determine the Purpose of Uninterruptible Power Supply

Electronics, Instrumentation & Electrical Database

Determine the Purpose of Uninterruptible Power Supply UPS

Continued from:

• Determine the general need for an UPS.
  • of Design and Selection of UPS

Determine the purpose of the Uninterruptible Power Supply UPS: An UPS may be needed for a variety of purposes. These include emergency lighting for evacuation, emergency perimeter lighting for security, shut down or continued operation of manufacturing equipment or computer operations, continued operation of life support or critical medical equipment, continued operation of communications, and safe operation of equipment during sags and brownouts. Some facilities need an UPS for more than one purpose. In any case, the purpose(s) must be known before proceeding because it determines many factors that will drive the amount of power required and the type of UPS that will be needed. These factors are the acceptable delay between loss of primary power and availability of UPS power, the length of time that emergency or backup power is required, and the criticality of the load that the Uninterruptible Power Supply UPS must bear. Applications such as hospital life support and safety, aircraft tracking and landing, and certain production process controls and data processing cannot tolerate any loss of power, no matter how short the period of time, without loss of life or revenue. Other applications like refrigeration, heating, and cooling may tolerate loss of power for several minutes (or longer) without any adverse effects. For data processing equipment, it may be necessary to maintain power until the equipment can be shut down in an orderly manner. This process may take only a few minutes. Alternatively, life support, safety, communications and security equipment, and other applications may require continuous power until primary power is restored. Restoration of primary power could take hours or even days. A survey of commercial power outages may be necessary to determine this information. If commercial power outages are historically infrequent and last only a few minutes or hours, it may not make economical sense to install an UPS capable of supplying power for several days.

Continue Determine the power requirements

References: “Joint Departments of the Army, Uninterruptible Power Supply System Selection, Installation, and Maintenance for Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities, 31 May 2002.”