In recognition of the critical role that data centers play in powering the UK’s digital economy and enabling the AI-driven future, today marks the launch of National Data Center Day – a milestone that Legrand is proud to support.

September 12th is the first-ever National Data Center Day and marks the one-year anniversary of data centers being officially classified as Critical National Infrastructure (CNI) by the UK Government. The purpose of the day is to raise awareness of data centers as the essential infrastructure that keeps the UK running, celebrate the people and innovation behind the industry, and improve public perception by showcasing the sector’s vital role in driving technological advancements, sustainability, and energy efficiency.

Data is the backbone of the digital economy, underpinning nearly every aspect of modern society, and Legrand is proud to play a vital role in supporting the infrastructure that powers this data with innovative, resilient, highly efficient, and sustainable solutions that ensure continuous availability - a true national priority.  

A Legacy of Sustainable Innovation

 Legrand is committed to environmental responsibility and dedicated to raising awareness not only in our own teams but also among our partners and customers. Our ambitious goals, as set out in our 2025–2027 Corporate Social Responsibility (CSR) Roadmap, include:

2050 Targets

• Net Zero by 2050: 90% reduction in greenhouse gas emissions (scopes 1, 2, and 3) compared to 2022 levels.

2030 Targets

• Reduce emissions: Scopes 1 & 2 by 42%, Scope 3 by 25% compared to 2022 levels.
• Eliminate single-use plastics: Phase out single-use plastics in all packaging.
• Enable carbon savings: Help customers to avoid 70 Mt of CO₂, through energy-efficient products and services (Scope 4).
• Eco-responsible portfolio: Achieve 80% of sales from solutions with a Product Sustainability Profile.  

These targets reflect Legrand’s mission of “improving lives with innovative and sustainable solutions”—a guiding principle that extends directly into our data center portfolio.

Energy-Efficient and Sustainable Product Portfolio

 From power and cooling to containment and connectivity, Legrand’s portfolio is designed to maximize efficiency, resilience, and sustainability across the entire data center ecosystem.

• Transformers: Green T.HE Transformers fully comply with the new eco-compatible design rules and guarantee a significant reduction in energy consumption, thereby promoting significant economic savings and the reduction of CO2 emissions into the atmosphere. Their cast resin encapsulation safeguards against fire and environmental hazards, while exceptionally low levels of partial discharge (below 5 pC) lead to a higher resistance to work stresses and ensure a longer life expectancy.

• High Power Busbar: The Xtra-compact (XCP) busbar trunking system delivers high-power distribution from 630-6300 amps in a smart and ultra-compact design. With up to a IP65 degree of protection, and reduced heat dissipation, it helps minimize cooling requirements and energy costs.

   

• UPS: Keor FLEX uses advanced Silicon Carbide (SiC) technology to maintain extremely high efficiency, even at varying loads. Achieving a market-leading 98.4% efficiency in double conversion mode, it reduces energy consumption, cooling costs, and Total Cost of Ownership (TCO). Its scalable design—supporting up to 1.2 MW in a single frame and expandable to 4.8 MW—makes it the ideal solution for colocation, hyperscale, AI, edge computing, and smart-grid-ready environments.

• Intelligent Rack PDUs: Raritan PX4 and Server Technology PRO4X PDUs provide granular, real-time power quality monitoring and metrics, enabling operators to identify and address inefficiencies. With ±0.5% energy metering accuracy, it provides ground-breaking rack-based metrics, including Neutral Voltage, Total Harmonic Distortion, Voltage Dips and Swells, Crest Factor, and more. When coupled with Waveform Capture, users can confidently reveal trends regarding the health and quality of power sources and power to devices at the rack PDU power inlet, circuit breakers, and outlets, enabling optimization of rack power efficiency.

• Cooling Solutions: The ColdLogik Rear Door Heat Exchanger (RDHx), an air-assisted liquid cooling system, is designed for AI workloads. With adaptive technology, it can reduce cooling-related energy consumption by up to 90%. Using a closed-loop water system, it delivers significant water savings that free up resources for community use.

• Cabinets: Minkels Airflow Management Solutions reduce air leakage and effectively prevent bypass and recirculation airflow, greatly reducing cooling energy demand. Platform features include blanking plates, cable entry seals, air sealing plinths, and sealing strips for bayed cabinets. The result is a truly sealed cabinet package that, when housed in any Legrand hot or cold aisle containment design, provides data center owners and operators with the most complete, cost-effective, and energy-efficient infrastructure solution available on the market.

• Fiber Solutions: The acclAIM low-loss HD fiber redefines connectivity by replacing pre-terminated cassette-based solutions with direct connections, which reduces additional components and costs. acclAIM offers the only connectivity on the market with a near-lossless link, almost unlimited scalability, and no gender considerations. The Direct Mating Breakout and Application Defined Polarity vastly improve density and flexibility, enable sustainable migration, and significantly improve the system lifecycle.

Powering Progress –Ensuring a Greener Infrastructure Future

 As National Data Center Day unfolds, we celebrate the industry’s progress—and recommit to where we must go next. Legrand stands at that intersection of innovation and responsibility, exemplifying how sustainable, future-ready data center infrastructure can—and must—power tomorrow.

Learn more about how we go further to deliver reliable, efficient, and sustainable solutions - working with you to future-proof your data center for a greener tomorrow here. 

Choosing the Right UPS: Why Selection Matters

UPS selection is a critical decision for any organization tasked with protecting sensitive equipment, data, and operations. Whether you're building a new facility or upgrading an existing power infrastructure, the uninterruptible power supply you choose must be aligned with your application’s power profile, load type, battery runtime expectations, and redundancy requirements. The wrong system (whether underpowered or overbuilt) can lead to inefficiencies, unnecessary costs, or worse, failures during outages.

This guide offers a structured, expert-led approach to selecting UPS systems, helping you match capacities and configurations to real-world conditions. It draws on best practices, practical design considerations, and highlights the modular capabilities within Legrand’s diverse UPS product range to support better decision-making.

Core Considerations for Effective UPS Selection

1. Define the Protected Equipment and Load Profile

UPS selection begins with a clear understanding of what you're protecting. Start by cataloging all connected devices, including:

• Servers and storage arrays
• Networking devices (routers, switches, firewalls)
• Building control systems
• Industrial controllers or medical devices
• Business-critical computers and workstations

For each device, determine the VA or watt rating, startup current, and whether it requires continuous backup or orderly shutdown.

Best practice: Include only critical equipment in your UPS load calculation. Non-essential devices (e.g., monitors, printers) may be better served by surge protection or alternate backup paths.

2. Determine Runtime Requirements and Battery Strategy

The amount of battery backup time needed varies by application. For many IT loads, 5 to 15 minutes of runtime is sufficient to bridge short outages or allow controlled shutdown. For healthcare, manufacturing, or edge data applications, 30 minutes to several hours may be required.

Considerations include:

• Do your devices require zero interruption, or is graceful shutdown acceptable?
• How long does the generator or alternate supply take to activate (if applicable)?
• Will you need external battery cabinets or extended runtime modules?

Legrand systems like the Trimod HE and Daker DK Plus offer scalable battery configurations and flexible runtime profiles tailored to both short-ride-through and long-duration backup requirements.

3. Select the Appropriate UPS Topology

Not all UPS systems are designed alike. Selecting the right topology depends on your application’s criticality and power environment.

For most business-critical environments, online UPS systems are the base standard. They ensure consistent power delivery, filter voltage sags or surges, and support sensitive equipment without interruption.

4. Factor in System Scalability and Redundancy

UPS selection isn't just about current needs, it’s also about planning for growth. Choose a system that supports modular expansion, allowing you to scale as your equipment base or backup duration increases.

Legrand’s KEOR MOD and Trimod HE platforms are designed for scalable deployment, supporting capacities from 25 to 250 kVA in modular blocks. These systems also support N+1 and 2N redundancy, ensuring backup capacity even during maintenance or internal failures.

Real-world tip: Redundant systems help meet uptime SLAs and regulatory requirements, especially in data centers, finance, healthcare and industrial automation sectors.

5. Evaluate Power Quality and Environmental Conditions

The environment in which your UPS operates will influence your system selection. Consider:

• Input power quality: Are there frequent surges, harmonics, or voltage fluctuations? Online systems are better suited for unstable supplies.
• Temperature and airflow: Batteries degrade faster in poorly ventilated or hot areas.
• Space constraints: Rack-mounted systems (like Legrand’s Daker DK) offer compact protection for tight IT spaces.
• Installation location: Edge sites and distributed branches may require smaller form factors with high resilience.

UPS systems are not just about backup—they also serve as power conditioning devices, protecting equipment from silent failures and long-term wear caused by poor-quality input.

Common Mistakes in UPS Selection and How to Avoid Them

• Underestimating runtime needs: Always match battery capacity to realistic outage scenarios, not theoretical minimums.
• Sizing for watts, not VA: UPS capacities are expressed in VA/kVA. Ensure you account for the power factor.
• Failing to account for inrush currents: Equipment like servers or motor-based devices may require higher capacity at startup.
• Ignoring system monitoring: Choose systems that integrate with SNMP or building control for proactive alerts.
• Selecting a fixed system in a growing environment: Opt for modular UPS platforms that allow additional capacity to be added as the application evolves.

Legrand Solutions for Precise UPS Selection

Legrand’s UPS portfolio is engineered to support a broad range of applications and sizing strategies:

• KEOR MOD
  Modular three-phase UPS system, scalable from 25 to 250 kVA. Designed for large IT, colocation, and industrial environments.
• Trimod HE
  Hot-swappable transformerless UPS ideal for enterprise IT and healthcare applications, available in 5–80 kVA capacities.
• Daker DK Plus
  Compact, line-interactive and online UPS models designed for desktop and rack-mount installations, from 1 to 10 kVA.

Each system is designed with modularity, battery flexibility, and real-time monitoring in mind. Ensuring your backup infrastructure evolves alongside your critical systems.

A Strategic Approach to UPS Selection

UPS selection is not a one-size-fits-all exercise. It requires a clear understanding of your protected equipment, application requirements, growth projections, and battery expectations. The right system should not only meet your current load but support future scalability and provide confidence during critical events.

Legrand’s uninterruptible power systems are built for precision, reliability, and ease of integration. Whether you’re protecting a small branch office, building-wide control systems, or enterprise-scale data infrastructure, our UPS products provide the capacity, protection, and flexibility to meet your goals.

To get expert guidance on selecting the right UPS for your application, connect with a Legrand specialist.

Understanding the Shift to Transformerless UPS

At Legrand, our transformerless UPS systems have become a cornerstone of mission-critical infrastructure design, trusted across global data centers, healthcare, and industrial applications. As power demands grow and data center operators seek more efficient, scalable, and cost-effective uninterruptible power supply (UPS) solutions, the transformerless approach delivers on key performance metrics, without compromising reliability or capacity.

At their core, transformerless UPS systems eliminate the bulky internal isolation transformer found in older designs. Instead, they rely on high-frequency technology, advanced power electronics, and intelligent charging circuits to provide clean, stable voltage to connected loads. This shift enables a more compact footprint, greater energy efficiency, and lower operational costs - all essential benefits in today’s high-density environments.

Key Components and System Architecture

Transformerless UPS units share core similarities with transformer based systems—such as rectifiers, inverters, batteries, and bypass circuits but their internal layout and energy flow differ significantly.

Major components include:

• Input Rectifier and Power Factor Correction (PFC): Converts incoming AC voltage to DC and ensures optimal current draw from the utility grid.

• DC Link: Acts as the central node between rectifier and inverter stages.

• Inverter: Converts DC back to a precise AC output to supply the critical load.

• Battery Charger and Batteries: Manages charging and discharging cycles for backup power support.

• Static Bypass: Offers immediate transfer to utility in case of UPS fault or overload conditions.

By removing the transformer, these systems significantly reduce impedance and improve response times to load changes, an essential requirement for sensitive IT, medical, and industrial applications.

Comparing Transformerless vs. Transformer Based UPS Designs
 

Benefits of Transformerless UPS Systems

Transformerless UPS technology offers more than just reduced physical size. Its benefits are directly aligned with the operational priorities of today’s mission-critical environments:

1. Higher Efficiency and Lower Operating Costs

Legrand’s transformerless UPS solutions consistently deliver superior energy efficiency compared to traditional transformer-based systems, helping customers reduce operating expenses without compromising reliability. Many models operate above 96% efficiency at full load, and support ECO and Smart Active modes that push efficiency even higher (up to 98–99%). Thanks to the integration of new technologies and advanced power components such as silicon carbide (SiC) semiconductors, efficiencies exceeding 98% are now becoming more achievable and widespread. These performance gains translate to real-world savings, each 1% increase in efficiency can reduce annual electricity and cooling costs by thousands of dollars in medium to large-scale facilities.

The Legrand  Keor HPE series exemplifies this benefit, offering 96% double-conversion efficiency in a compact, high-reliability monolithic design ideal for critical loads.

2. Improved Power Quality and Fast Response

With advanced digital signal processors and high-speed switching, these systems can respond to power disturbances in microseconds. They ensure voltage stability, maintain frequency regulation, and support nonlinear loads without degradation of output quality.

KEOR MOD is ideal for edge environments where fast inverter response prevents cascading failures during voltage dips or transient disturbances.

3. Scalability and Design Flexibility

As digital infrastructure expands across hybrid and edge environments, Legrand’s transformerless UPS systems offer modular scalability that reduces upfront investment while enabling seamless power expansion. 

Products like the KEOR MOD and Trimod HE feature hot-swappable power modules, allowing facilities to start small and scale up to 250kVA or more without service interruption. Ideal for growing colocation sites or distributed IT architectures.

4. Reduced Total Cost of Ownership

Lower initial costs, reduced energy consumption, and minimized maintenance requirements combine to deliver a compelling long-term financial case. Additionally, simpler installation procedures and free air cooling in some models further lower overall costs.

5. Enhanced Battery Management

Transformerless UPS systems use digital battery management and temperature-compensated charging to optimize charging cycles, extend battery service life, and reduce strain during float conditions. Legrand UPS solutions support both VRLA and lithium-ion battery technologies—offering up to 60% longer lifespan, faster recharge times, and reduced cooling requirements compared to legacy chemistries.

Our integrated battery monitoring tools provide real-time runtime forecasting, failure detection, and intelligent alerts through DCIM and SNMP interfaces, empowering facilities to prevent downtime and optimize replacement cycles.

Limitations and Design Considerations

While transformerless UPS designs offer numerous benefits, they are not without limitations. Proper system design and understanding of the use case is essential:

• Susceptibility to Dirty Power: In environments with high harmonics, voltage distortion, or electrical noise, transformerless UPS units may be more vulnerable to instability. Additional filtering or conditioning equipment may be required.

• No Built-In Galvanic Isolation: Without an internal transformer, isolation from the utility or faults is absent. In some applications, external isolation transformers may be required—adding cost, complexity, and footprint.

• Lower Short-Circuit Current Capability: Transformer based systems can deliver higher phase-neutral fault currents, which is advantageous for downstream protection coordination.

• External Transformer Design Risks: Relying on external isolation increases the number of components that must be monitored and maintained, introducing potential single points of failure if not managed correctly.

Applications Across Critical Industries

Transformerless UPS systems are well-suited for a broad range of applications where high availability and power protection are non-negotiable.

• Data Centers : Optimal for rack-based deployments and colocation sites needing flexible, high-density power supplies.

• Healthcare Facilities: Supports diagnostic equipment, surgical suites, and life-sustaining systems where voltage fluctuations are unacceptable.

• Industrial and Manufacturing: Transformer based UPS may be preferred in heavy-duty applications with complex fault management and higher power levels.

• Telecom Networks: Ensures uptime across distributed infrastructure and remote installations, especially in edge or 5G deployments.

• Financial Institutions: Maintains system integrity for trading floors, transaction servers, and compliance infrastructure.

Real-World Design Considerations

When selecting and deploying a transformerless UPS, technical decision-makers should evaluate several key parameters to ensure alignment with facility needs:

• Load Profile and Capacity: Determine the kVA rating required for peak and average loads, accounting for potential growth.

• Battery Runtime: Assess backup requirements and choose battery capacity and chemistry accordingly.

• Voltage Compatibility: Ensure output voltage matches downstream equipment and regional standards.

• Redundancy and Bypass Design: Consider N+1 or 2N redundancy for critical applications.

• Environmental Conditions: Confirm that ambient temperature, airflow, and humidity are within operating specs for optimal performance.

• Need for Isolation: Evaluate whether external galvanic isolation is needed and its impact on cost and layout.

Future Outlook and Standards Alignment

Transformerless UPS systems are increasingly becoming the default architecture for modern installations, particularly as energy efficiency regulations tighten and rack densities continue to rise. Industry standards such as IEC 62040, which governs UPS performance and safety, and IEEE 446, offering best practices for standby power systems, continue to evolve to keep pace with these technological advancements. With innovations in silicon carbide (SiC) switching, lithium-ion batteries, and intelligent energy management platforms, transformerless UPS designs are poised to become even more efficient, compact, and capable. The focus on software integration for predictive maintenance and real-time diagnostics is also expanding the role of the UPS as an active component in facility-wide infrastructure management.

Making the Case for Transformerless UPS

For organizations seeking reliable, scalable, and energy-efficient uninterruptible power, transformerless UPS systems deliver clear, measurable advantages. From lower costs and smaller footprints to improved efficiency and better battery management, the benefits of this technology are aligned with the needs of modern, digitally driven operations.

However, decision-makers should also consider specific site conditions, load sensitivity, and required protection levels. In rugged industrial environments or applications demanding galvanic isolation and fault resilience, transformer based UPS systems may still be preferable.

Whether you're building a new facility or retrofitting legacy infrastructure, transformerless systems offer a future-proof solution that supports evolving workloads and operational demands. 

Our KEOR FLEX, KEOR HPE, Trimod HE, and Daker DK series UPS platforms provide scalable, efficient power protection for even the most demanding environments.