What types of cables are run in structured cabling trays

Structured cabling trays typically carry power, control, instrumentation, and communication cables, all of which must be tray-rated and UL-listed for safety and compliance.

Common Cable Types

1. Tray Cable (TC) Tray Cable, defined under NEC Article 336, is a factory-assembled cable with two or more insulated conductors, optionally including grounding conductors, enclosed in a non-metallic jacket. TC cables are rated for 600 volts and are used for industrial power or control circuits. They are suitable for indoor, outdoor, and hazardous locations when properly rated, and TC-ER (exposure-rated) cables can extend up to six feet outside the tray if supported and secured . 2. Instrumentation Tray Cable (ITC) Instrumentation Tray Cable, covered under NEC Article 727, is designed for control and instrumentation applications. ITC cables can be shielded or unshielded, with multiple single conductors or twisted pairs, and may include metal armor for additional protection. These cables are used in environments requiring precise signal transmission and protection from electrical noise . 3. Metal-Clad (MC) Cables MC cables are often used as an alternative to TC cables for 600-volt motor power or control circuits. They feature a metallic sheath that provides mechanical protection and can be installed in cable trays where additional durability is required . 4. Fiber Optic and Communication Cables Cable trays also support fiber optic and low-voltage communication cables, which are used for data transmission, networking, and telecommunication. These cables are typically non-metallic and may include additional shielding to prevent interference . 5. Control and Power Cables In addition to TC and MC cables, trays can carry control cables for automation systems and power cables for distribution within industrial or commercial facilities. These cables must be rated for the environment, including temperature, moisture, and potential exposure to chemicals or mechanical stress .

Key Considerations

• UL Listing and Tray Rating: All cables in trays must be UL-listed and marked as cable tray rated to ensure compliance with NEC Section 392.10(A) and related articles .
• Environmental Ratings: Cables may be rated for indoor, outdoor, corrosive, or high-electrical-noise environments.
• Mechanical Protection: Some cables, like MC or armored ITC, provide additional protection against crushing or impact.
• Installation Practices: Proper securing, spacing, and fill limits must be followed to maintain ampacity and prevent overheating . Structured cabling trays provide a safe, organized, and accessible pathway for these cables, allowing for easier maintenance, future expansion, and compliance with electrical codes .