Common Wire Types Used in Data Centers

Artificial intelligence (AI), cloud computing, and data use are rapidly expanding in the United States and globally, sparking demand for more computing power. 

According to Microsoft, more than 30 percent of working-age Americans use AI. And as the number of users grows, so does the number of data centers coming online to support them. Pew Research cites more than 3,000 live data centers in the United States, with many more coming online soon. 

Though states like Virginia, Texas, and California lead the way in data center growth, new locations are gaining traction. For example, Eastern Oregon and Arizona offer lower-cost land in energy-abundant, low-risk areas. For example, Eastern Oregon and Arizona offer lower-cost land in energy-abundant, low-risk areas like Hassayampa Ranch, where a $25 billion facility has been proposed. 

And as companies move to erect data centers, less expensive, rural, and climate-safe regions become prime opportunities. 

But powering data centers requires a jaw-dropping amount of wire and cable. Whether it's power, lighting, data transmission, or facility safety, each wire serves a specific purpose. Together, they keep these massive facilities operating at peak performance 24/7. 

What is a Data Center? What Does it Do? 

Though data centers come in several types, their main goal is to store and process vast amounts of online information. This includes website storage, training AI, eCommerce management, and video and audio streaming. Virtually everything we do online forces us to interact with a data center at some point. 

And depending on the facility’s owner, the data may serve one company, a group of businesses, or the public. A few common data center types include: 

Enterprise - Designed, built, and operated for a single company 

Cloud - Run by third-party companies like Google, Microsoft, or Amazon, these facilities process and store data for other companies 

Hyperscale - Large-scale facilities used for high-performance, low-latency tasks like AI, big data, and advanced computing 

Managed Services - Third-party-owned data centers hosting standard data management and monitoring services to end-users 

Edge Data - Small buildings near end users designed to reduce latency and bandwidth without reducing service speeds 

The typical data center can range from only a few thousand square feet to hulking 100,000 sq. ft. facilities. Within these buildings, computers, servers, and networking components allow data to live and move through the facility seamlessly. 

But data centers are more than oversized computer rooms. They contain servers, cooling systems, backup power sources, and security systems — all to keep things running smoothly. 

And, as you can imagine, keeping these sites operational takes immense amounts of electricity. 

Huge Buildings Fuel Massive Needs 

Developing the front lines of technology is no easy feat. 

Facilities need thousands of feet of wire and cable to supply the power needed to run everything. The need stretches far beyond running power, too. Whether it's connecting servers, running complex biometric and security systems, or grounding, everything needs cable. 

Data centers aren’t one-size-fits-all solutions, either. Sites may require unique specs, including high-purity bare copper (ETP), Cat8 copper wiring, or ultra-high-speed fiber optic cabling to process data as efficiently as possible. 

Wire configurations are important for moving data, but conductors can’t move data and electricity as effectively without the right insulation and jackets protecting them. Insulation and jacketing protect conductors from crushing, chemical contact, water, heat, and electromagnetic interference (EMI). The right protection also makes a difference during a fire by limiting smoke and toxic fumes. 

But what wire types are most commonly used in modern data centers and what do they do? 

Electrical Power Distribution 

As their name implies, power cables supply electricity to machines and systems. 

Medium Voltage (MV) Feeder Cables 

MV cables handle up to 35kV and carry power from substations and utility lines to nearby transformers. The transformer then steps the voltage down to usable levels to safely power the data center. MV cables also connect power generators and uninterrupted power supplies (UPS) for use during power outages. 

Other applications include connecting solar panels and wind turbines to substations and the electrical grid. 

EPR/PVC or Low Smoke Zero Halogen (LSZH) Jacketed Wires 

EPR/PVC cables provide several benefits, including flexibility, moisture resistance, and high-temperature performance. This wire powers switchgears, circuit panels, and high-voltage motors. 

In public areas, LSZH jacketed wire is optimal because it produces little smoke and no halogens while burning. During a fire, standard wire insulation can create thick smoke as it melts, making it hard to see. Meanwhile, halogens released during burning can mix with surrounding air to create toxic fumes. 

Although LSZH is a global standard, in the U.S., make sure any wire or cable used in plenum spaces is either CMP (for copper) or OFNP (for fiber) rated. 

XHHW-2 for Conduit 

This wire type works well for continuous-load circuits, generators, batteries, and UPS situations. XHHW-2 also helps power machines and HVAC and cooling systems. 

THHN/THWN Wire 

Choosing which of these wires to use often depends on the environment. 

THHN is best used indoors, including branch circuits and high-heat areas. THWN is moisture-resistant, making it a go-to for outdoor applications like power feeds and underground runs. 

Tray Cables (TC, TC-ER, PLTC, PLTC-ER, ITC) 

Tray cables are the unheralded workhorses of many industries, including data centers. 

These multi-conductor cables run power from substations to main distribution boards (MDBs) and server rack power distribution units (PDUs). You can also find these cables used with battery packs and UPS systems. 

Thanks to their PVC jacketing, tray cables are easy to pull through conduit. The slick outer covering protects the inner system, including conductors, from abrasion and other damage. As a result, tray cables are great for connecting power to boxes, switchgear, appliances, and other machines. 

Metal Clad (MC) Cable 

Unlike other cables, MC cables have an aluminum or steel covering protecting the conductors inside. The metal shell reduces crushing, abrasion, and impact damage, while preventing EMI issues. 

MC cable is suitable for areas where conductors might come into contact with moisture, chemicals, dust, or other contaminants. 

SOOW/SEOOW Cables 

Data centers use SOOW and SEOOW cables for portable and temporary power. 

Both cable types feature oil-resistant inner conductor insulation and overall jacketing. They’re also moisture-resistant, making them great for outdoor applications and areas where contact with water or oil could occur. SEOOW is even more impressive, as it can operate at 600V while submerged in water. 

Since these wires only supply temporary power, they work best for lighting, tools, and portable carts. If the component is part of a permanent installation, use tray cable instead. 

Variable Frequency Drive (VFD) Cables 

VFD cables provide power to machine motors and control their speed by varying the voltage and frequencies used. 

These cables have a copper braid or foil shielding that helps contain any generated EMI. By preventing EMI from escaping, VFD cables prevent potential interference with other nearby cables, including Cat6A data wires. 

The cable's design also includes XLPE or PVC insulation to help the cable better handle voltage changes and spikes and dissipate voltage buildup. And unlike standard wiring options, VFD cables have a symmetrical grounding system. This prevents damage to connected motors, minimizing potential fail points and increasing reliability. 

Infrastructure and Safety 

Data centers are jammed with expensive equipment. The wires in this section maintain a safe environment for people and machines and serve as backup power. 

Bare/Green Insulated Copper Grounding Wire 

Ground wire provides electrical systems with a safe path to earth, protecting extremely sensitive and expensive equipment from damage. 

DC Battery Cable 

Although many parts of a data center operate using AC power, critical components of the facility run on DC. This includes fire alarms and security systems, switchgear, generator output breakers, and circuit breakers. 

Data centers use DC battery cables to connect redundant batteries to electrical systems. These batteries supply DC power to the facility when AC power falters, keeping systems running with supplemental power. 

Controls, Lighting, and Monitoring 

From lights and cooling to monitoring and safety, these wires ensure every backend system runs smoothly. 

Small Gauge Instrumentation Wires (18-22 AWG) 

Small gauge wires fill many roles, most notably for powering safety and monitoring systems, including: 

• Temperature tracking 

• Environmental monitoring 

• Cooling system monitoring 

• Sprinklers 

• Smoke detectors 

• Biometric scanners 

This wire is easy to bend and work with in tight areas, making it great for installers. However, it's worth noting that the smaller the wire gauge is, the less effective it is for longer runs. 

Building Automation and Control Networks (BACNet) Cables 

These shielded cables serve as low-voltage communication and signal cables to help coordinate and control critical infrastructure that maintain a data center's servers. 

The cable’s shielding makes it resistant to electrical noise and carries a low capacitance, making it a cost-effective and easy solution for linking server rooms over long distances. 

Beyond connecting server rooms, BACNet cables also control cooling loops, support power systems, and monitoring systems. 

Class-2 (Low Voltage) Lighting Cables 

These small insulated wires power low-voltage LED lights less than 30V. You can find Class-2 wire tucked in plenum areas powering magnetic locks, security cameras, and thermostats, and other low-energy devices. 

Although they typically handle low voltage, Class-2 wiring must have a 150V rating for higher currents. 

Data Movement 

Data centers store and move information in real-time. To accomplish this feat, facilities need systems designed for high speed and reliability. 

Data Cables (Cat6A, Cat8, Fiber Optic Cable) 

Many data centers use Cat6A as the standard, though Cat8 is an option for short-distance data transfers because of its speed. 

Companies use fiber optic cable to transmit data at ultra-high speeds. Despite sometimes long transmission lengths, fiber optic cable has low signal degradation and can resist EMI from nearby wires. 

Coaxial Cable 

Most people know coaxial cable as a communications and television workhorse, but it has a home in data centers. 

Coaxial cable has unique layers comprised of a conductor, dielectric insulator, shielding, and jacket. This multi-layer design prevents signal leakage while maintaining constant electrical impedance. 

This wire supports radio frequency (RF) signals, media satellite feeds, timing systems, and distributed antenna systems (DAS). The DAS is especially important, since it allows cell service inside the facility. Without them, data centers would be dead zones. 

Many Wires, One Goal 

Data center infrastructure is complex and beautiful, with thousands of different cables working in concert to do incredible things. 

Our reliance on the internet and online resources is constantly expanding. In turn, so is the role data centers play in supporting and expanding our capabilities. 

And while the servers inside those windowless buildings act as each facility’s beating heart, the wire and cable winding through their corridors are the veins. 

Without them, power doesn't flow, cooling systems lose their edge, and security becomes an afterthought.