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Powering Tomorrow: UL Listings and Their Role in Safeguarding Data Centers

Data centers consume enormous amounts of power, up to 1,000 kWh per square meter. This consumption is due to a combination of factors, primarily the vast arrays of server racks (made up of 40 to 50 servers) constantly retrieving, storing, sending, and receiving data. This generates  large amounts of heat, but the servers must be kept at specific temperatures (64°F to 80°F) to ensure they operate at optimum capacity. This requires any data center's second largest power consumer: its cooling system. 

The consequences of ineffective cooling systems can contribute to major issues for the data center premises and the organization running it, including:

  • Extreme overheating, which significantly damages equipment, can cause permanent data loss, requires expensive replacement, and causes danger to data center employees.

  • Service downtime, which can create significant costs and damage reputation.

  • Hazardous situations, such as fires,which can put data center employees in danger.

  • Power loss, leading to data corruption and, depending on length, further cooling system problems.

Data center designers, builders, and operators adhere to several safety standards to protect against these issues and ensure effective power supply throughout the premises. In the U.S., these safety standards are the general National Electric Code (NFPA 70) and various Underwriter Laboratories (UL) listings, which apply to equipment and practices used in data centers. 

An AI image of a data center

UL 1778 – Safety Standard for Uninterruptible Power Systems

Service downtime is one of the biggest costs data centers can suffer, up to $11,000 per minute. To guarantee 24/7 service and zero downtime, data centers deploy Uninterruptible Power Supply (UPS) systems, usually consisting of large batteries, which kick in instantaneously when mains power drops to cover the transition period to emergency power supplies. 

The UL 1778 standard gives guidelines for the components and equipment used in these UPS systems and how to test them to ensure they perform as intended when power drops.  

UL 508A – Safety Standard for Industrial Control Panels

Control panels with HMI systems are important for helping data center operators understand power usage and depower sections for repairs or replacement. The UL 508A standard covers enclosed and open-type industrial control panels and the certification of the empty enclosure itself. UL 508A is the most common certification for industrial control panels and certified equipment, and in data centers, it is found in use with:

  • Fire suppression systems

  • HVAC systems

  • Control valves

  • Pumps

  • Elevator controls

  • Electric motors

  • Service equipment

The UL 508A standard lists guidelines for the proper design and assembly of industrial control panels, including component selection, the design and spacing of components within the panel, and safety measures to reduce risk for operators. Ensuring UL 508A certification for all control panels in a data center limits hazardous situations such as equipment or conductor overload and short circuits or overvoltage. 

UL 891 – Standard for Safety for Switchboards

Data centers are highly dependent on permanent power supply, be that mains power, emergency gensets, UPS systems, or even on-site renewables (wind, solar) picking up loads. This means that the electrical switchgear used to manage the data center’s electrical distribution system is critical in minimizing circuit overloads and safely switching from one power source to another, protecting equipment and operators. UL 891 is the safety standard that covers the design, construction, and operation of electrical switchgear rated to 1000V or less.

The standard outlines best practices and components, such as circuit breakers and fuses, which can detect and isolate faults, switch circuits, and manage several power sources efficiently.

UL 924 – Safety Standard for Emergency Lighting and Power Equipment

The particular design of data centers, with temperature regulation and consistency a high priority, means there is generally no natural light. As such, during any hazardous event, employees completely rely on artificial and emergency lights to evacuate or conduct repairs. 

UL 924 provides a safety standard for designing and installing emergency lighting (such as exit signs and floor markings) and power equipment. Some of the most notable guidelines include the obligation for emergency lighting to remain powered for at least 90 minutes after the loss of mains power, a 10-second ‘switchover’ time to emergency power systems, and the use of particular batteries and other components in emergency power.

UL 62368-1 – Safety Standard for Audio/Video, Information and Communication Technology Equipment

UL 62368-1 is the latest version of the UL safety listing for IT equipment, transitioning from UL 60950-1, released around the turn of the century. For data centers, this standard covers a wide variety of equipment, including:

  • Computing and networking equipment (server racks, routers, laptops, PCs, and their respective power supplies)

  • Communication equipment (network infrastructure, phones, intercom systems)

  • Display equipment (monitors, TVs, digital displays)

  • Office equipment

The standard focuses on hazard prevention and covers topics such as the power distribution units (PDUs) for ICT equipment, how UPS systems integrate with them, and how factors such as surge protection, materials used, and power cords affect safety.

UL 864 – Safety Standard for Control Units and Accessories for Fire Alarm Systems

Fire is one of the biggest hazards in data centers, so effective fire alarm systems are essential for operator safety and minimizing equipment damage. UL 864 applies to the control units, equipment, and components of a fire alarm system. Some topics covered in the standard include the construction of enclosures for fire alarm systems and materials to be used, the wiring of the system, and protecting the systems from electrical faults, which is especially necessary when the system will be needed.

An AI image of a data center


Data centers are a cornerstone of the modern digital world, and investment continues to grow with even greater demand for low-latency data. However, the server racks and the cooling systems that protect them require very large amounts of power, which, combined with the heat produced by the servers, can create hazardous situations for operators and equipment.

To ensure a safe operating environment for employees and minimize equipment damage, expensive service downtime, and reputation damage, data center designers and operators adhere to several safety standards, mostly from Underwriter Laboratories (UL). Along with the NEC/NFPA 70, these UL listings give guidelines for materials, spacing, wiring, and best practices for reducing hazards involved with data center equipment.

At Enercon, we work with data centers to design, assemble, and install the electrical equipment required for safe and effective operation. We have UL certification for data center equipment such as low and medium-voltage switchgear (UL 891, UL 1558) and control panels (UL 508A, UL 698A). To learn more about how we can help you ensure a safe working environment and regulatory compliance at your data center, contact our team here.

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