DATA CENTRE CABLING: POWER AND NETWORK CONNECTIVITY FOR HIGH-DENSITY RACKS

A data centre rack requires two cable categories: power cables for PDU-to-server connections and network cables (Cat.6A or Cat.7) for high-speed data transmission. High-density racks also need thin-diameter patch cables to maintain airflow, and all cables should be LSZH (Low Smoke Zero Halogen) rated for fire safety compliance. LAPP provides both ÖLFLEX® power cables and ETHERLINE® network cables from a single manufacturer—covering every connection in the rack with consistent quality and unified technical support.

Data centre construction across ASEAN is accelerating as hyperscale operators and colocation providers expand to meet regional cloud demand. Behind every server rack sits a cabling infrastructure that determines network performance, power reliability and long-term maintainability. This guide covers the cable types you need for data centre racks, how to prevent electromagnetic interference between power and data runs, the fire safety ratings your cables must carry and how LAPP’s portfolio addresses both sides of the rack.

What cables do you need for data centre racks?

Every data centre rack requires cables on two parallel paths: power distribution from the facility PDU to each server, and network connectivity from each server to the top-of-rack switch or patch panel.

Power cables. These distribute AC or DC power from the PDU (Power Distribution Unit) to individual servers and networking equipment. Industrial-grade power cables like ÖLFLEX® provide the current-carrying capacity, flexibility and fire safety ratings that data centre environments demand. Key requirements include LSZH sheathing for enclosed spaces, adequate conductor sizing for the rack’s total power draw and sufficient flexibility for neat routing within cable management arms.

Network cables (structured cabling). The data side of the rack uses Cat.6A or Cat.7 Ethernet cables. Cat.6A supports 10 Gigabit Ethernet up to 100 metres at 500 MHz bandwidth—the current standard for most enterprise and colocation deployments. Cat.7 extends to 600 MHz with individual pair shielding (S/FTP), providing headroom for 25GbE and 40GbE upgrades. LAPP’s ETHERLINE® range covers both categories with industrial-grade construction designed for demanding environments.

Patch cables. Pre-assembled ETHERLINE® patch cables connect servers to the patch panel. In high-density racks with 40+ servers, cable diameter matters—thinner cables improve airflow and reduce congestion in cable management trays. LAPP offers Cat.6A patch cables with RJ45 connectors in standard lengths, ready for immediate deployment.

How do you prevent EMI between power and data cables?

Electromagnetic interference (EMI) is one of the most common causes of network errors in data centres—and one of the most preventable. When power cables and data cables run parallel in the same tray or bundle, the electromagnetic field from the power cable induces noise in the data cable. This causes bit errors, retransmissions and reduced throughput.

Four practices minimise EMI in rack cabling:

Separate power and data paths. Route power cables on one side of the rack and data cables on the other. Use dedicated cable management on each side. This physical separation is the single most effective EMI reduction measure.

Use shielded data cables. Cat.6A S/FTP and Cat.7 S/FTP cables include individual pair shielding plus an overall screen. This shielding attenuates external EMI by 20–40 dB compared to unshielded equivalents. ETHERLINE® Cat.6A and Cat.7 cables use S/FTP construction for maximum noise rejection.

Maintain crossing angles. Where power and data cables must cross, ensure they cross at 90°. Parallel runs of power and data cables in close proximity should be avoided entirely.

Ground shielding properly. Shielded cables only work when the shield is properly terminated and grounded at both ends. LAPP’s shielded ETHERLINE® patch cables include shield continuity through the RJ45 connector for reliable ground paths.

LAPP’s data centre portfolio: from PDU to patch panel

LAPP covers both the power and data sides of data centre infrastructure:

ÖLFLEX® power cables. Industrial-grade power distribution cables in LSZH variants for PDU connections, busbar trunking feeds and rack power whips. Available in a range of conductor sizes to match rack power requirements from single-server setups to high-density deployments.

ETHERLINE® Cat.6A. Installation cables and patch cables supporting 10GbE at 500 MHz. S/FTP shielded construction with LSZH sheath. Suitable for horizontal runs from patch panel to server and for structured cabling backbone.

ETHERLINE® Cat.7. High-performance installation cables operating at 600 MHz with individual pair shielding (S/FTP). Provides bandwidth headroom for 25GbE and 40GbE upgrades without having to replace cabling infrastructure.

ETHERLINE® patch cables. Factory-terminated Cat.6A patch cables with RJ45 connectors. 100% tested for insertion loss, return loss and crosstalk. Available in multiple lengths for flexible rack deployment.

SKINTOP® cable glands. IP-rated cable entry for panel and cabinet installations where environmental sealing is required.

FLEXIMARK® labelling. Colour-coded, machine-printable labels for cable identification across power and data runs—essential for efficient maintenance and troubleshooting in facilities with thousands of cables.

What cable ratings are required for data centre fire safety?

Data centres are enclosed, high-value environments where cable fire safety directly affects business continuity. Three ratings matter:

LSZH (Low Smoke Zero Halogen). When standard PVC cables burn, they release dense smoke and toxic halogen gases that damage equipment and endanger personnel. LSZH cables produce minimal smoke and no halogenic acid—critical in enclosed server rooms where evacuation routes are limited and equipment value is high. All LAPP ETHERLINE® data centre cables are available in LSZH variants.

Flame retardancy. Cables must self-extinguish and not propagate fire along cable trays. Look for IEC 60332-3 (flame propagation for bunched cables) certification—more stringent than single-cable testing and realistic for dense rack environments.

CPR (Construction Products Regulation). For data centres in markets that follow EU standards, cables must carry a CPR euroclass rating. Class B2ca or Cca is typical for data centre installations. Confirm the CPR classification for your specific market requirements.

Specifying LSZH from the start avoids costly cable replacement during compliance audits. Many facility managers discover non-compliant cabling only during certification inspections—resulting in unplanned downtime and rewiring costs that far exceed the marginal cost of specifying LSZH cables initially.

Talk to our engineers

LAPP’s application engineers help data centre teams specify the right cables and connectors for new builds and upgrades. From PDU power distribution to top-of-rack network patching, LAPP covers both sides of the infrastructure with industrial-grade components designed for high-availability environments. They review your rack density, power requirements, network speed targets and fire safety standards to recommend a matched power-and-data cabling package.

Browse the ETHERLINE® data communication range and ÖLFLEX® power cables on the JJ-LAPP eShop, or explore LAPP’s industrial Ethernet solutions for detailed specifications.

Contact the team to discuss your data centre cabling requirements and receive specification support for your next facility project.