Why It Matters: High‑voltage and limited energy circuits routed too closely can cause cross‑talk, distortion, or packet errors, especially in dense cable trays or congested ceiling spaces. Best Practice: Use separate trays, conduits, or divider systems to isolate voltage classes. Maintaining proper separation between power, data, and limited energy cabling is foundational to system performance, safety, and code compliance. Separation isn't just an EMI precaution — it protects signaling, reduces rework, and ensures pathways meet inspection expectations across risers. What steps can be taken to separate data and power cable trays in retrofit situations? In retrofit situations, separating data and power cable trays is critical to minimize electromagnetic interference (EMI) and comply with standards such as NEC (National Electrical Code) and TIA/EIA. The following. When power and communications cables intersect, the code specifies that they should cross perpendicularly, at a 90-degree angle. At this crossing point, the two-inch separation is not typically required because the length of the parallel exposure is minimized. A well-engineered cable tray layout isn't just a matter of neatness; it's a critical factor in ensuring system reliability, safety, electromagnetic compatibility (EMC), and. Keeping data cables separated from power cables significantly reduces EMI risk. Cable trays are a support system for electrical cables, power, signal, and communication and optical fiber cables. NEC section 300-8 does not permit any tube, pipe, or equal for water, air gas, drainage, steam, or any service other than electrical in raceways or cable trays containing.