CL2 is the abbreviation for Class 2 Cable, a designation defined by the National Electrical Code (NEC) that applies to low-voltage cables used for circuits operating at limited power levels. CL2 cables are designed to safely transmit signals and power in systems that operate at 150 volts or less, providing insulation and fire resistance suitable for use in commercial and industrial environments.
Class 2 (CL2) cables are engineered for low-voltage applications where power levels are inherently limited, reducing the risk of electrical shock or fire. These cables are constructed to comply with NEC Article 725, which classifies wiring systems based on voltage and energy transmission characteristics. CL2 cables feature insulation capable of withstanding up to 150 volts and are tested for flame retardance to ensure they meet building and safety requirements for general-purpose use.
In commercial and industrial facilities, CL2 cables are commonly used for systems that transmit control signals, communication data, and low-power electrical currents. Their construction typically includes stranded copper conductors insulated with materials like PVC, polyethylene, or other thermoplastic compounds designed for durability and flexibility. CL2 cables can be found in applications such as security systems, intercoms, HVAC control, access control systems, and certain AV or automation networks.
CL2-rated cables are also available in variants such as CL2R (riser-rated) and CL2P (plenum-rated), which meet additional requirements for installation in specific building spaces. The CL2 rating itself indicates that the cable meets general safety requirements for use in commercial structures where low-voltage performance and fire safety are essential.
Commonly regulated under the National Electrical Code (NEC), specifically Article 725, and tested for performance and safety under UL (Underwriters Laboratories) guidelines. UL’s testing ensures compliance with voltage limitations, insulation standards, and flame resistance for commercial and industrial use.
The CL2 designation emerged as part of the NEC’s broader classification system for power-limited circuits, introduced to create clear standards for low-voltage wiring safety. Over time, as building automation and communication systems expanded, CL2 cables became a widely recognized standard across industries for their reliability and compliance with national fire and safety codes.
These applications benefit from CL2 cables’ balance of electrical performance, durability, and compliance with safety regulations for power-limited circuits.