Power and low voltage wires should be routed through a single cable tray

Power and low-voltage wires should generally not be routed together in a single cable tray unless separated by a solid barrier or sufficient spacing to prevent interference and comply with NEC standards.NEC and Industry GuidelinesThe National Electrical Code (NEC) and industry best practices recommend separating high-voltage (power) and low-voltage (signal or control) cables to avoid electromagnetic interference, voltage crossover, and potential damage to sensitive circuits . Specifically:NEC 392 governs cable tray installations, including fill limits, cable types, and separation requirements .Class 1 power circuits should not share space with Class 2 or Class 3 low-voltage circuits unless the low-voltage circuits are reclassified and installed using Class 1 wiring methods .Medium-voltage cables (above 600V) must never share a tray with signal cables .Separation MethodsTo safely route mixed-voltage cables:Use separate trays for power and low-voltage circuits whenever possible .Divider brackets or compartmentalized trays can allow cables to share a tray while maintaining physical separation .Maintain minimum spacing: For power cables rated 600V or less and Class 2/3 signal cables, a minimum of 2 inches separation is required, though many industrial installations use 12 inches vertical separation for added safety and reduced interference .Shielded cables can reduce interference but do not replace the need for proper separation .Crossing cables at 90 degrees is recommended when power and signal cables must intersect .Practical ConsiderationsTray fill: Avoid overfilling trays; power cables require more space than low-voltage cables, and exceeding fill limits can cause overheating and maintenance difficulties .VFDs and high-frequency noise: Variable frequency drive output cables can induce interference in nearby signal cables; maintain separation or use conduit for sensitive circuits .Inspection readiness: Separation violations are common inspection failures, so following NEC and TIA standards ensures compliance and reduces costly rework .ConclusionFor safety, reliability, and code compliance, power and low-voltage wires should be routed in separate trays or separated by solid barriers within a shared tray. Proper spacing, shielding, and tray selection are essential to prevent interference, maintain cable integrity, and meet NEC requirements.