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. In industrial settings, electrical and instrumentation (E&I) cable trays or bridge racks play a critical role in organizing and supporting power, control, and signal cables across facilities. The NEC permits power and signal cables in the same tray under specific. Answer: No. 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. Separating high-voltage power cables from low-voltage communication cables is a fundamental requirement in any electrical installation.