Question 1

What is the maximum cable run length for CAT6?

Accepted Answer

The permanent link (horizontal cable from patch panel to outlet) is limited to 90m for CAT5e, CAT6, CAT6A, and CAT7. The total channel length including patch cables at each end is 100m maximum. This 90/10 split allows 5m patch cable at the comms room end and 5m at the outlet end. Exceeding 90m permanent link will cause signal degradation and test failures. If runs exceed 90m, consider relocating the comms room or using fibre optic cable.

Question 2

Should I install CAT6 or CAT6A?

Accepted Answer

CAT6A is strongly recommended for new installations in 2026. While CAT6 supports 1 Gbps at 250MHz, CAT6A supports 10 Gbps at 500MHz over the full 100m channel. With Wi-Fi 7 access points now requiring 10 Gbps backhaul, and PoE++ (90W) becoming common, CAT6A provides the bandwidth and power-handling for current and future needs. The cable is thicker (7.5mm vs 6.2mm OD), so ensure conduit and trunking are sized accordingly.

Question 3

How many data outlets do I need per desk/room?

Accepted Answer

BS EN 50173 recommends: Offices — minimum 2 outlets per workspace (one for data, one for VoIP/spare). Meeting rooms — 2-4 outlets plus wireless access point. Each 10m of corridor — 1 outlet for WAP. Server rooms — 2 outlets per cabinet. The guideline of 'two outlets per 10m² of office space' is a good starting point. Over-provision by 20% for future growth — it's far cheaper to install cables during construction than to retrofit.

Question 4

What is a structured cabling system?

Accepted Answer

A structured cabling system is an organised, standards-compliant cable infrastructure that supports multiple hardware uses and is independent of the equipment connected to it. It comprises: Horizontal cabling (patch panel to outlet, max 90m), backbone cabling (between floors/buildings, typically fibre), work area (outlet to device), equipment room (servers, switches), and telecommunications room (floor distribution). It is designed per BS EN 50173 to a 15-20 year life.

Question 5

Do I need to segregate data cables from power cables?

Accepted Answer

Yes — to prevent electromagnetic interference (EMI), data cables should be separated from power cables. BS EN 50174-2 recommends: Unscreened data cable — minimum 200mm separation from single-phase power cables, 300mm from three-phase. Screened (STP/FTP) cable — minimum 50mm separation. If cables must cross, they should do so at 90 degrees. In shared trunking, a metal divider must separate power and data compartments. Segregation is critical for achieving certified performance.

Data Cabling Calculator — CAT6/6A Structured Cabling

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