16 Networking Systems
The best power practices presented below provide enterprise
data center planners and operators with a roadmap for optimizing the efficiency, availability and capacity of new and existing
There is growing interest in using non-isolated transformer-free UPS modules in three-phase critical power applications.
Transformer-free UPS systems are typically constructed of
smaller, modular building blocks that deliver high power in
a lighter weight with a smaller footprint and higher full load
efficiency. Isolated transformer based UPSs provide “Maximum
Protection.” Non-isolated transformer-free UPSs provide
UPS system configurations and efficiency options
A variety of UPS system configurations are available that provide
high utilization rates in addition to high availability. Today’s
high-availability, double-conversion UPS systems can achieve
any data center design project is configuring systems to meet
current requirements while ensuring the ability to adapt to
future demands. In the past, this was accomplished by over-sizing
systems and letting the data center grow into its infrastructure
over time. That no longer works because it is inefficient in
terms of capital and energy costs. The new generation of infra-
structure systems is designed for greater scalability, enabling
systems to be right-sized during the design phase without risk.
Enable data center infrastructure management
Data center managers tend to fly blind, as they lack visibility
into the real-time system performance required to optimize efficiency, capacity and availability. Availability monitoring and
control has historically been used by leading organizations, but
managing the holistic operations of IT and facilities has lagged.
This is changing as new data center management platforms
emerge that bring together operating data from IT, power and
cooling systems to provide unparalleled real-time visibility into
Figures 1a and 1b. A UPS with Active Eco-Mode and Double Conversion Mode with high efficiency at the desired power load can provide reliable
power protection and flexibility for the data center.
efficiency levels similar to less robust designs without the risk of
downtime through the use of advanced efficiency controls.
There may also be opportunities to increase efficiency in the
distribution system and switchgear use by distributing higher voltage power to IT equipment. A step down from 480 V to 208 V in
the traditional power distribution architecture introduces minimal losses. Using 575-V critical bus with a 575-V to 240-V PDU
improves gear utilization, improves efficiency and keeps fault
currents in check.
Design for flexibility using scalable architectures that
One of the most important challenges that must be addressed in
Utilize local design and service expertise
While best practices in optimizing availability, efficiency and
capacity have emerged, there are significant differences in how
these practices should be applied based on specific site conditions, budgets and business requirements.
In an enterprise data center power system, high-efficiency
options work within proven system configurations to enhance
efficiency while maintaining availability. Power distribution
technologies provide increased flexibility to accommodate new
equipment, while delivering the visibility into power consumption required to measure efficiency.
Most importantly, a new generation of infrastructure management technologies is emerging that bridges the gap between
facilities and IT systems, and provides centralized control of the