18/4 Plenum-Rated Fire Security Control Cable - CMP CL3P 300V

In this review the focus is on the 18/4 plenum-rated control cable and who will benefit most from it: installers and building managers who need a flame-retardant, flexible low-voltage cable for fire alarm, security, intercom and similar systems. The single biggest reason to buy is its CMP/CL3P plenum rating combined with stranded bare copper conductors, which gives confidence for installation in ceiling plenums and other air-handling spaces while keeping conductivity and handling performance high.

Key Features

• Plenum-rated CMP/CL3P: Highest flame retardant grade allows routing in ceiling plenum spaces used for air distribution, reducing fire and smoke risk.
• Stranded 100% copper conductors: Stranded bare copper provides improved conductivity and flexibility for easier termination and reliable signal transmission.
• 300V CL3 rating: Rated for 300V and Class 3 power-limited circuits, making it suitable for thermostats, security panels and similar low-voltage uses.
• Multiple applications: Designed for fire alarms, burglar stations, public address, intercoms, nurse call and access control systems for broad installation use.
• Standards compliant: Meets NEC 725 & 800 and UL standards UL 13 and UL 444, and is UL or ETL listed and RoHS compliant for code-friendly installations.

Who It's For

Electricians, low-voltage installers and facility maintenance staff who must run cables through plenum spaces will find the cable well suited to commercial, institutional and some residential retrofit projects. The plenum rating and UL/ETL listings make this a practical choice for code-conscious projects that require reliable signal and power-limited wiring.

It is not aimed at high-voltage power distribution or outdoor direct-burial use; while UV resistant and suitable for some outdoor low-voltage routing, projects that require armored, shielded or specialty outdoor-rated cable should consider other products.

Pros & Cons

Pros

• High flame retardant CMP/CL3P rating allows safe routing in plenum air spaces.
• Stranded bare copper conductors offer good conductivity and make the cable easy to strip and terminate.
• Broad application support for alarm, intercom, PA, telephone and access control systems.
• Compliant with NEC, UL and CSA standards, simplifying code approval.

Cons

• Some customers note the cable feels thin for certain aesthetic lighting runs, so it may not suit every low-profile visual application.

Specifications

Conductor	Stranded bare copper
Configuration	18 AWG, 4 conductors
Flame rating	CMP / CL3P / FT6 (Plenum-rated)
Voltage rating	300V (Class 3 power-limited)
Standards	NEC 725 & 800; UL 13 & UL 444; CSA-C22.2 No. 2556
Listing	UL and/or ETL listed; RoHS compliant

Our Verdict

The 18/4 plenum-rated control cable is a practical, code-conscious choice for professionals running fire alarm, security and communication circuits in plenum spaces. Its stranded copper conductors and UL/ETL listings deliver reliable performance and easier handling, representing good value for installation projects that require the higher flame-retardant CMP rating.

Frequently Asked Questions

Can this cable be run in ceiling plenum spaces?
Yes; it is CMP/CL3P plenum-rated specifically for use in air-handling plenums and similar spaces.

Is the conductor material solid or stranded?
The cable uses stranded bare copper conductors for flexibility and reliable conductivity.

Is this suitable for outdoor use?
It is UV resistant and can be used for some outdoor low-voltage applications, but it is not a direct-bury or armored outdoor power cable.