WEST KINGSTON, R.I. – February 25, 2002

– American Power Conversion (Nasdaq: APCC) (APC) today announced PowerStruXure; a patent-pending, systematic approach to building data center physical infrastructure that allows for a "pay-as-you-grow" scenario. This entirely new approach to data center support simplifies the design, building and management of data center infrastructure with an innovative, fully engineered and tested system. PowerStruXure allows additional capacity to be purchased and installed when needed via simple "building blocks," therefore reducing the upfront capital investment required to undertake data center projects.

"The complexity of forecasting dynamic processing loads against a typical capital expense cycle has put IT and facilities managers in a difficult position. If too much physical infrastructure capacity is built and demand is not there, overhead costs can soar. On the contrary, if lead times are long, data center build-outs can become a bottleneck and revenue can be constrained," said Rodger B. Dowdell, Jr, APC's president and CEO. "PowerStruXure helps to address these issues and offers these managers the ability to get not only their servers and software on demand, but their physical infrastructure as well."

Based on extensive meetings with industry professionals in the information technology, communications, facility and engineering communities, APC has developed this architecture to address the issues present in the deployment of the full range of data centers. Initial adoption by several leading companies has illustrated its unique benefits.

"Helping customers and partners develop, test and fine tune their software applications in the Microsoft.Net environment is our mission. APC's PowerStruXure, which was installed and commissioned literally in a matter of hours in our data center, provides us with a scalable infrastructure for managing the power to these applications," said Navdip Bhachech, managing consultant, Microsoft Technology Center-Silicon Valley.

"The APC PowerStruXure architecture has allowed us to put into place an 'on demand' physical infrastructure, which significantly reduces capital costs, optimizes operating expenses, and increases availability to our mission critical operations," said Michael Marston, assistant vice president, Systems, OneBeacon Insurance.

Key benefits of the new PowerStruXure architecture include:

·

Optimized Capital Investment

- the rack-based design allows for the purchasing of equipment that coincides with the current data center need, thereby leading to reduced capital investment and faster deployment. Scaling the system for future needs is fast, simple and affordable.

·

Adaptability to Changes in the Environment-

The frequent technology refresh cycles in IT installations place special demands on the physical and power infrastructure in data centers large and small. Only PowerStruXure has the modular building blocks that allow the physical infrastructure to rapidly respond to changes in total power requirements, changes in voltage requirements, changes in data center size and location, and changes in rack power density. Furthermore, PowerStruXure can be integrated into existing data centers, eliminating the need to abandon previous infrastructure investments to meet the needs of developing IT equipment.

·

Increased Manageability of Support Equipment

- The PowerStruXure system utilizes an Information Controller that creates a private network within the PowerStruXure. This allows all of the information within the system to be aggregated back to a centralized location known as an Information Controller. Data center managers can then manage the entire PowerStruXure from a single interface that includes a web-based interface and that integrates with most major Building and Network Management Systems.

·

Faster Deployment with Simplified Planning and Engineering

- PowerStruXure systems are pre-engineered, pre-tested, and mostly pre-assembled leading to a drastic simplification of up-front planning and engineering. This can dramatically shorten the planning, engineering, and deployment times for creating a data center.

The three initial core solutions that comprise PowerStruXure are a modular, scalable, N+1 redundant uninterruptible power supply (UPS); zoned, intelligent power distribution; and a next generation rack enclosure. The adaptability of the architecture allows for a variation between a zoned or centralized design based on the application of the project. The variety of deployment options available when purchasing PowerStruXure make it an ideal infrastructure solution for everything from a small computer room to large enterprise, colocation and service provider data centers.

"With the development of PowerStruXure, APC has identified and solved major hurdles that IT and facility professionals face in the build-out or enhancement of data centers," continued Dowdell. "PowerStruXure was designed, developed and engineered to deliver real business value to data center managers in both smaller and larger applications."

The flexibility of PowerStruXure provides almost any data center with a unique infrastructure support system without the extensive customized engineering that most traditional systems demand. PowerStruXure is available in three categories, each with a high degree of scalability built into its design, so that the installation is simple and fast and need only be based on the current size and power requirements of a data center.

These categories of PowerStruXure are:

·

Data Room/Intermediate Distribution Frame (IDF)/Main Distribution Frame (MDF)/Wiring Closet (<500sq ft)

- PowerStruXure Type A is a simple and easy way to install a complete uninterruptible power solution ideal for data rooms, MDF/IDFs, and wiring closets. This approach minimizes exposure to downtime through its highly manageable and fully integrated rack-based infrastructure. The foundation of the PowerStruXure Type A is the Symmetra® RM Rack Mounted N+1 fault tolerant UPS scalable from 2-12 kVA. This is combined with a high density, pre-wired, and metered rack power distribution system to allow a

row of racks to be assembled and powered up in minutes without custom electrical work. An optional row expander provides the ability to add additional rows of racks as needed without additional wiring or planning. This complete system utilizes APC's NetShelter® VX, the next generation enclosure.

·

Medium to Large Data Centers (500-5,000 sq. feet)

- PowerStruXure Type B, designed specifically for the data center environment, is a simple to install, rack-based infrastructure design that is easily adaptable to changes within the data center. Type B is comprised of the newly designed Symmetra three-phase 10-40kW N+1 UPS, a modular, scalable UPS offering the highest power density in today's market; a rack-based power distribution unit (PDU) with system bypass isolating the UPS from the critical load; a power distribution system to provide power to the enclosures; an Information Controller that collects and aggregates information from the various APC subsystems and integrates them into traditional building management systems; and APC's NetShelter VX, the next generation enclosure.

·

Large Data Center/Facility Applications (5,000 sq. feet +)

- PowerStruXure Type C is an ideal solution for centralized power protection in medium to large data centers. Ideal for installations of 1MW or greater, PowerStruXure Type C is scaleable and modular in design, allowing for the addition of power in 200kW increments as they are needed, leading to a dramatic decrease in up-front capital investment by eliminating the need to purchase power and equipment not required at the time of install. In addition, PowerStruXure Type C includes the power distribution components and Information Controller available in Type B.

APC's PowerStruXure is currently available in North America and will be available in Europe, the Middle East and Africa in the third quarter of 2002 and in most remaining geographies in the fourth quarter of 2002. Additional information on APC's PowerStruXure or any of its products and services can be found on APC's web site at

www.apcc.com/powerstruxure

or by calling APC at 800-877-4080.

About American Power Conversion

Founded in 1981, American Power Conversion (Nasdaq: APCC) (APC) is a leading provider of global, end-to-end infrastructure availability solutions. AP's comprehensive products and services offering, which is designed for both home and corporate environments, improves the availability, manageability and performance of sensitive electronic, network, communication and industrial equipment of all sizes. APC, which is headquartered in West Kingston, Rhode Island, reported sales of $1.43 billion for the year ended December 31, 2001 and is a Fortune 1000 and S&P 500 company.

All trademarks are the property of their owners. Additional information about APC and its global end-to-end solutions can be found at

www.apc.com

or by calling 800-877-4080.

About OneBeacon :

Headquartered in Boston, Massachusetts, OneBeacon Insurance Group is committed to being the leading independent agency property/casualty insurance group in the Northeast. With roots dating back 170 years and a current A.M. Best rating of A (excellent), OneBeacon boasts a heritage of keeping promises, backed by financial strength. We offer a wide range of personal, commercial and specialty products and services, which are sold exclusively through select property/casualty independent agents.

OneBeacon Insurance Group is wholly owned by White Mountains Insurance Group, Ltd., of Hamilton, Bermuda. White Mountains' principal businesses are conducted through its subsidiaries and affiliates in the business of property/casualty insurance and reinsurance. The company is publicly traded on the New York Stock Exchange under the symbol "WTM."

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