SYSTON 18/2 Shielded Plenum Alarm Control Cable - CMP Rated

In this review of the SYSTON 18/2 Shielded Plenum Alarm Control Cable the bottom line is straightforward: this cable is aimed at installers and facility managers who need a reliable, low-voltage control wire that can be run in plenum spaces. The reviewer found the single biggest reason to buy is the combination of stranded pure copper conductors with aluminum foil shielding and a CMP plenum rating, which together deliver consistent signal performance and the safety to install in air-handling spaces. This makes it a practical choice for fire alarm, security, and other power-limited circuits.

Key Features

• Plenum-Rated CMP: The CMP/CL3P/FT6 flame retardant construction allows safe installation in building plenums and ceiling return-air spaces without compromising safety.
• Stranded Pure Copper Conductors: Stranded bare copper cores provide good conductivity and flexibility, making the cable easier to route in tight runs than solid conductors.
• Aluminum Foil Shielding: A full aluminum foil shield reduces electromagnetic interference, keeping signals clear for alarms, intercoms, and access control wiring.
• 300V CL3 Rating: The 300V insulation and CL3 classification ensure this cable meets Class 3 power-limited circuit requirements for low-voltage systems.
• Multiple Application Support: Designed for fire alarms, burglar stations, public address, telephone, nurse call, and other low-voltage communication or control uses.
• UV Resistant Jacket: The outer jacket resists UV exposure for short-term outdoor routing or protection in exposed areas while maintaining flexibility.

Who It's For

This cable is best for professional electricians, AV installers, security contractors, and building maintenance teams who need a code-compliant cable for plenum spaces and power-limited systems. It is particularly useful where shielding is important to avoid interference from nearby electrical runs or equipment.

It is less suitable for heavy power distribution, outdoor direct burial, or applications that require thicker gauge conductors for higher current. Hobbyists expecting a very thick cable should note some users describe the jacket and conductor bundle as relatively thin compared with larger power cables.

Pros & Cons

Pros

• Good signal integrity from the aluminum foil shield that blocks EMI for sensitive communication circuits.
• Flexible stranded copper conductors make routing through conduits and panels easier than solid wire.
• High safety margin with CMP plenum rating and 300V insulation for low-voltage installations in air-handling spaces.
• Versatile for many low-voltage systems including alarms, intercoms, and access control.

Cons

• Some customers report the cable feels thinner than expected, which can be a limitation if a heavier duty jacket or larger conductor is required.
• Not intended for direct burial or high-voltage applications, so additional protection is required for harsh outdoor use.

Specifications

Conductor	Stranded bare copper
Pair/Size	18/2
Shielding	Aluminum foil full shield
Rating	CMP / CL3P / FT6 (Plenum-Rated)
Voltage	300V (CL3)
Applications	Fire alarm, security, PA, intercom, telephone, access control

Our Verdict

The SYSTON 18/2 Shielded Plenum Alarm Control Cable is a practical, code-minded choice for professionals installing low-voltage, power-limited systems in buildings with plenum space runs. Its stranded copper conductors and full foil shielding deliver reliable signal performance, and the CMP rating adds an important safety advantage. For those needing a thicker jacket or outdoor burial cable, a different product would be better, but for indoor plenum and protected outdoor routing this cable offers solid value.

Frequently Asked Questions

Can this cable be run in ceiling plenums?
Yes, it is CMP plenum-rated and designed for use in air-handling spaces and return-air plenums.

Is the cable shielded against interference?
Yes, a full aluminum foil shield reduces electromagnetic interference to protect signal integrity in sensitive circuits.

Can it be used for outdoor direct burial?
No, it is not intended for direct burial; use protective conduit or select a cable rated for outdoor burial for those installations.