Issue link: https://www.e-digitaleditions.com/i/1192126
62 I ICT TODAY Support: Cable Pathway and Wire Mesh Trays Flexibility, particularly in installations with multiple cable drops, is also important when planning the cable pathway (Figure 6). In the case of runways, new designs offer movable cross members that allow for maximum flexibility. Radius drops can be placed exactly where they are needed to path cable into or out of the vertical manager. Additionally, easy-to-use tool-less pathway dividers allow the user to maintain required space between cable bundles within the pathway as dictated by industry standards. Another popular cable support solution is the wire mesh cable tray, which can be supported from the wall, ceiling, floor or from the tops of open racks. When look- ing for wire mesh cable trays, look for designs featuring smooth edges to protect cable and installers from getting hurt, as well as zinc plating to allow electrical continuity through splice connections. Considerations for selecting a robust cable pathway solution include: 1. Route Will the cable pathway require irregular transitions or simple turns? Look for tool-less and adjustable designs that allow for ultimate flexibility in the pathway. 2. Support The pathway should be able to support cables from the ceiling, wall, racks or floor with adequate space support away from sources of electromagnetic interference (EMI). 3. Weight Based on the size of runway and tray and distance between supports, what is the maximum weight supported? The support must be designed using a 50 percent fill of cabling to allow for future growth. 4. Bonding and Safety Consider designs with integrated bonding studs to make installation easier. Is the bond appropriate for the circuits carried per local electrical code? Make sure the pathway is securely supported and bonded. 5. Accessibility Is the pathway isolated from nontechnical staff but still accessible for new cable runs? 6. Accessories Each egress/ingress point should provide sufficient protec- tion for cables. This includes ensuring cables are properly divided/organized within the runway or tray for easy tracing. 7. Heat NFPA-70 and TIA TSB-184-A also address heat buildup and limit cable fill based on the types of circuits. PoE circuits above 60 Watts (high-amperage power circuits) fall into this category. 8. Corrosion Resistance Is the pathway located where it will be exposed to weather, chemicals or other environmental conditions that require an additional layer of corrosion protection? Consider a cost-effective corrosion-resistant finish with resistance class IEC 61537 Class C8 that delivers corro- sion resistance almost equivalent to stainless steel. FIGURE 6: Flexibility, particularly in installations with multiple cable drops, is also important when planning the cable pathway.