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. EMI risk increases with parallel runs and long shared pathways. 3 (C) (1) still apply to cables in the tray system? 392. 3 (C) (1) is more strict requiring the. 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. 3 (C) (2) of the National Electrical. Cable tray barriers can be used to separate conductors operating over 600 volts from other conductors in the same tray operating at 600 volts or less. Separating high-voltage power cables from low-voltage communication cables is a fundamental requirement in any electrical installation. This practice is mandatory for two distinct reasons: ensuring the safety of the structure and its occupants, and preserving the integrity of sensitive data.