Cable Fire Rating CMP CMR CM CMG CMX Meaning


Industry Dynamics



First, the supercharger level -MPMP-class (blast test / Plenum Flame Test / Steiner TunnelTest)

This is the most prestigious Plenum Cable in the UL fire protection standard. The applicable safety standard is UL910. The test stipulates that multiple samples are laid on the horizontal air duct of the unit and burned with 87.9 KW gas Bunsen burner (300,000 BTU / Hr) 20 minutes. The standard of qualification is that the flame must not extend beyond 5 feet from the flame front of the Bunsen burner. The peak optical density is a maximum of 0.5 and the average density is a maximum of 0.15. This CMP cable is typically installed in an air-return booster system for ventilation ducts or air handling equipment approved by Canada and the United States. FEP / PLENUM materials complying with UL910 have better flame retardancy than low-smoke, halogen-free materials complying with IEC60332-1 and IEC60332-3, and low concentrations of smoke.

CMP: Filled level communications cable, which is the highest cable security rating, with perfect flame retardancy and low smoke and toxin emissions. According to the UL definition, a bundle of CMP cables must be self-extinguishing within less than 5 meters of combustion spread under fan intensive combustion conditions. CMP cables use Teflo-based chemicals to stop burning and disperse, minimizing emitted fumes and toxins. This adds significant cost to the lower UL rated cables. CMP grade cables are used in buildings where cables are laid in the ventilation return passage. In the event of a fire, the building will not be filled with a lot of smoke or hazardous toxins from the cables. CMP grade cables must undergo a rigorous combustion test: UL910- "Flame Propagation and Smoke Density Value Test"

Second, the trunk-level-CMR (Riser Flame Test)

This is a UL standard commercial cable (Riser Cable), the applicable safety standard UL1666. The test requires the laying of multiple specimens on a simulated vertical axis with the specified 154.5 kW gas Bunsen burner (527,500 BTU / Hr) for 30 minutes. The eligibility criteria for the flame can not spread to the upper part of the 12-foot-tall room. Mainline cables have no smoke concentration specifications and are generally used for vertical and horizontal floor wiring.

CMR: Mainline communications cable. This is the second most rated cable, which has perfect flame retardancy but does not test emitted fumes and toxins. In addition to CMP and cables, CMR cables and all other communication cables use halide-based chemicals, such as chlorine, to stop the spread of combustion. By definition, a bundle of CMR cables must be extinguished within less than 5 meters of combustion spread under fan forced combustion conditions.

CMR cable jackets are typically made of a type of PVC that emits chlorine gas in the combustion chamber. The chlorine gas depletes the oxygen in the air and extinguishes the flame. CMR grade cables are widely used in trunk applications where the ventilation system is physically separated from the cabling system. This is very common in Asia and Australia. CMR-class cables must undergo intensive flame testing: UL1666- "Cable Flame Propagation Level Test for Vertical Mounting to Middle"

Third, the commercial-CM level (vertical combustion test Vertial Tray Flame Test)

This is the UL standard commercial grade cable (General Purpose Cable), the applicable safety standard UL1581. The test requires that multiple test specimens be placed on a vertical 8-foot support and burned (70,000 BTU / Hr) for 20 minutes with a prescribed 20 kW ribbon burner. Pass the standard flame can not be spread to the top of the cable and go out on their own. UL1581 and IEC60332-3C similar, but the number of laying cables varies. Commercial-grade cables have no smoke concentration specifications and are generally used only for horizontal routing of the same floor and should not be used for vertical routing of floors.

Fourth, the general level - CMG level (vertical combustion test Vertial Tray Flame Test)

This is the UL standard General Purpose Cable (General Purpose Cable), the applicable safety standard UL1581. Commercial and general purpose test conditions are similar, with Canada and the United States approved. General-purpose cable without smoke concentration specifications, generally only applies to the same level of horizontal alignment, not on the floor of the vertical wiring.

CM / CMG: General Communication Cabling. This is common in the building's horizontal alignment, which is usually divided into smaller bundles compared to CMR cables. CM / CMG cables use halogen-based chemicals when grouping. By definition, in a small bundle of cables, the CM / CMG cable must be self-extinguishing within less than 5 meters of its combustion spread. The flame is not forced to use a fan to burn. CM / CMG cable jackets are typically made from a class of PVC that emits chlorine gas in the combustion chamber. CM / CMG cables are commonly used for horizontal routing in the UK, Asia and Australia. CM / CMG cable must pass CSA FT-4 "vertical combustion test"

Fifth, household level - CMX level (vertical combustion test Vertial Wire Flame Test)

This is UL standard Restricted Cable, applicable to UL1581, VW-1. The test procedure was to keep the sample vertical and burn for 30 seconds with a test torch (30,000 TU / Hr), then stop for 15 seconds and repeat 5 times. Eligibility criteria for the flame should not exceed 60 seconds, the specimen can not be burned more than 25%, at the bottom of the surgical cotton pad can not be ignited by falling objects. UL1581-VW-1 is similar to IEC60332-1, except that the burning time is different. There is also no smoke or toxicity rating for this class, only for home or small office systems where a single cable is laid. Such cables should not be used in bundles and must be shielded. Smoke density, halogen content and toxicity levels.

CMX: Residential Communications Cabling. This type of cable is limited to residential or other small applications where the number of communication cables used is very small, and these applications typically only have one cable laid. CMX-level tools can not be used in bundled cable applications. CMX cable must pass UL VW1 combustion test