18/4 CL3P Plenum Shielded Cable 500ft – White Pull Box

18/4 CL3P Plenum Shielded Cable – 4-Conductor EMI-Protected Bare Copper for Multi-Circuit Plenum Installs

18/4 CL3P plenum shielded cable is the versatile, interference-protected solution for multi-circuit installations in commercial plenum environments. This 500ft white pull box delivers four 18AWG stranded bare copper conductors, an aluminum foil shield with drain wire, and a CL3P-rated plenum jacket — purpose-built for security systems, CCTV, intercom, audio wiring, and building automation control circuits that require both EMI suppression and the flexibility to handle multiple signals on a single cable run.

Furthermore, this cable meets the fire safety requirements established under NEC Article 725 for power-limited Class 3 cable installations in plenum spaces (nofollow). As a result, it carries the CL3P rating — certifying it for air-handling plenums, HVAC ducts, drop ceilings, and riser shafts where flame spread and toxic smoke production must be minimized by code. Consequently, low-voltage contractors, AV integrators, and building automation engineers can specify and install this 18/4 CL3P plenum shielded cable with full confidence on any inspected commercial project.

Key Features of Our 18/4 CL3P Plenum Shielded Cable

• 4-Conductor Design — Maximum Wiring Flexibility: The four-conductor configuration is the defining advantage of this 18/4 CL3P plenum shielded cable over 2-conductor alternatives. A single cable run can simultaneously carry two independent circuits — for example, a signal pair and a power pair to a CCTV camera, separate transmit and receive channels for a two-way intercom, or multiple control zones for a building automation thermostat or relay. Moreover, the four-conductor format provides spare conductors on single-circuit applications, eliminating the need to repull cable if an additional circuit is required at the same device location in the future.

• Aluminum Foil Shield with Drain Wire: The overall aluminum foil shield encloses all four conductors with a bare copper drain wire for single-point grounding at the head-end equipment. This shield provides continuous 100% EMI and RFI coverage against adjacent cable bundles, lighting ballasts, HVAC motor starters, and building automation wiring sharing the same ceiling pathway. Furthermore, the drain wire ensures the shield can be correctly grounded to eliminate ground loops that would otherwise introduce hum or signal noise on sensitive audio and intercom circuits.

• 18AWG Stranded Bare Copper Conductors: Four 18AWG stranded bare copper conductors deliver the flexibility and conductivity required for complex low-voltage routing in commercial ceiling environments. Stranded construction bends around corners without fatiguing or kinking, making this cable ideal for runs that navigate through conduit, drop ceiling grid, and wall cavity without the risk of conductor fracture that affects solid wire on multi-bend pulls. Additionally, bare copper maintains superior long-term conductivity compared to copper-clad aluminum (CCA), which corrodes and increases resistance in humid ceiling environments.

• CL3P Plenum-Rated Jacket — NEC Article 725 Compliant: The white CL3P jacket is specifically tested and certified for installation in air-handling plenum spaces under NEC Article 725 for power-limited Class 3 circuits. This rating requires the cable to pass the UL 13 plenum cable construction and fire test standard (nofollow), confirming it will not contribute to flame spread or generate toxic smoke in an air-handling pathway. In other words, this cable is the correct and legally compliant specification for any power-limited low-voltage circuit in a commercial plenum ceiling.

• Security and CCTV System Compatible: The 4-conductor configuration makes this cable ideal for CCTV installations where both video signal and 12VDC or 24VDC power must be delivered to the camera over a single cable run. As a result, installers can complete both the video feed and camera power in a single pull, reducing conduit fill and simplifying rough-in on high-camera-count projects.

• Building Automation and Control System Ready: This 18/4 CL3P plenum shielded cable is suited for building automation thermostats, fan coil unit controllers, damper actuators, and relay circuits requiring multi-conductor shielded cable in plenum spaces. Furthermore, the shield is critical for building automation circuits that share ceiling pathways with high-frequency switching power supplies and variable frequency drives common in modern mechanical systems.

• Audio, Intercom, and Multi-Zone Sound Systems: The four conductors and EMI shielding make this cable ideal for two-way intercom wiring, multi-zone background music distribution, and stereo in-ceiling speaker circuits. Consequently, AV integrators can use a single SKU for intercom, paging, and audio zone circuits throughout a commercial build, simplifying procurement and inventory.

• 500ft Pull Box Packaging: The 500ft pull box provides enough cable for multiple full-floor circuit runs. Additionally, pull box packaging delivers tangle-free payout on active job sites, reducing installation time and material waste on multi-device, multi-circuit commercial deployments.

Why Choose This 18/4 CL3P Plenum Shielded Cable for Your Project?

The 4-conductor format is the key reason to specify this 18/4 CL3P plenum shielded cable over a 2-conductor equivalent. In commercial security, AV, and building automation work, the most expensive part of any cable installation is the labor — not the cable itself. A single 4-conductor run between a controller and a remote device eliminates the need for a second cable pull and a second conduit fill calculation for that circuit pair. Moreover, for projects using building automation systems where thermostat and sensor wiring commonly requires three or four conductors for power, signal, and common, this cable handles all connections in a single shielded pull without any splicing. Additionally, the four conductors provide a natural upgrade path — if a two-conductor circuit later requires an additional return or ground conductor, the spare conductors are already in the wall or ceiling without requiring a repull. For 2-conductor shielded plenum applications where the smaller profile is preferred, see our 18/2 CL3P CMP Plenum Shielded Cable 500ft White (DoFollow).

The shielded construction on this 18/4 CL3P plenum shielded cable is especially important in modern commercial buildings where building automation, AV, and security systems share ceiling plenum space with dense data cabling, LED driver wiring, and HVAC control conduits. Unshielded cable in these environments can develop induced noise on audio circuits, false trigger events on CCTV motion detection, and erratic behavior on BAS thermostat control loops — all of which generate costly service callbacks. Therefore, specifying shielded cable on every 4-conductor low-voltage circuit in a commercial plenum is a best practice that eliminates the most common source of unexplained system faults after occupancy. Furthermore, the ANSI/TIA-570-D residential and light commercial cabling standard (nofollow) recommends shielded cable in environments with elevated EMI potential — a recommendation increasingly applicable to modern commercial buildings packed with high-frequency switching electronics. For the complete range of shielded and unshielded CL3P plenum cables across all gauges and conductor counts, browse our full Speaker and Security Cable collection (DoFollow).

The white jacket on this 18/4 CL3P plenum shielded cable makes it the natural choice for audio, intercom, and building automation circuits where white cable is the standard color convention. White cable blends with white ceiling grid systems and white junction boxes, and is the expected color in finished commercial ceiling spaces where cable is visible during inspections or tenant walkthroughs. In other words, white maintains the professional appearance that building owners, facility managers, and AHJs expect in a properly completed commercial installation. For black jacket cable on security or access control circuits, see our 16/2 CL3P CMP Plenum Unshielded Cable – Black 500ft (DoFollow).

Frequently Asked Questions

Q: What applications specifically require 4 conductors rather than 2 in a plenum shielded cable?

Several common commercial low-voltage applications require 4 conductors rather than 2, making this 18/4 CL3P plenum shielded cable the correct specification over a 2-conductor alternative. CCTV cameras often require both a coaxial video conductor and a separate DC power conductor — but for analog HD cameras using HDCVI, HDTVI, or AHD over twisted-pair, four conductors provide the full signal and power circuit in a single cable. Building automation thermostats and zone controllers typically require three to four conductors for the R (power), C (common), Y (cooling), and G (fan) signals. Two-way intercom systems require separate transmit and receive conductor pairs. Additionally, multi-zone background music systems using impedance-matching volume controls require four conductors to support both the input and output connections at the volume control. Therefore, specifying 4-conductor cable as the default for multi-circuit low-voltage rough-in reduces the risk of discovering a two-conductor shortfall after the walls are closed.

Q: Can this 18/4 CL3P plenum shielded cable be used for building automation and HVAC control circuits?

Yes — this 18/4 CL3P plenum shielded cable is specifically listed in the confirmed application set for building automation and control systems. The 18AWG stranded bare copper conductors provide the flexibility required for connecting thermostats, VAV box controllers, damper actuators, and fan coil unit controllers that are typically located in plenum ceiling spaces directly adjacent to the mechanical equipment they control. The aluminum foil shield is critical for BAS circuits because variable frequency drives, compressor motor starters, and switching power supplies in the mechanical system generate the high-frequency interference most likely to corrupt BAS communications. Furthermore, the CL3P plenum rating ensures code compliance in the air-handling spaces where most BAS wiring is routed. As a result, specifying this cable eliminates the two most common BAS commissioning problems: insufficient conductors and EMI-induced communication errors on the control network.

Q: Is the shielding on this cable appropriate for CCTV and security camera installations in plenum ceilings?

Yes — this 18/4 CL3P plenum shielded cable is well-suited for CCTV and security camera installations in commercial plenum environments. The aluminum foil shield protects the video signal conductors from the electromagnetic interference that causes noise, banding, and color distortion on analog CCTV feeds running near fluorescent lighting, switching power supplies, and other low-voltage cable bundles in the same ceiling space. The 4-conductor format allows a single cable to deliver both the video signal pair and the 12VDC or 24VAC camera power pair in the same pull, eliminating a separate power cable run to each camera location. Additionally, the CL3P plenum rating ensures the cable is compliant for installation in the air-handling ceiling spaces above drop ceilings where the majority of commercial CCTV cameras are mounted. Consequently, this cable simplifies both rough-in planning and inspection approval on CCTV projects in commercial plenum environments.

18/4 CL3P plenum shielded cable from 52Networks delivers 4-conductor versatility, EMI-shielded signal protection, and CL3P-certified fire safety for every commercial security, AV, and building automation installation. Order today and receive a 500ft white pull box ready for your next plenum project.