Explaining UL Flame Retardant Wire Standards For You

- Jan 01, 2020-

The so-called flame retardant wire is simply understood as an unburnable wire. Generally, we call Teflon wires flame retardant wires. But in fact, flame retardant means that under specific test conditions, the flame spreads and the residual flame extinguishes itself within a specific time. For this reason, UL has formulated different flame-retardant grades according to different conditions.


Any wire or cable listed by UL has been tested and verified to meet a certain fire rating, and the cable can be printed with the UL identification, fire rating and approval number.


Booster stage-CMP stage (Plenum Flame Test / Steiner Tunnel Test)

This is the highest required cable (Plenum Cable) in the UL fire protection standard. The applicable safety standard is UL910. The test requires that multiple samples be laid on the horizontal air duct of the device. 87.9KW gas Bunsen burner (300,000BTU / Hr) is used to burn 20 minute. The eligibility criterion is that the flame must not extend beyond 5 feet from the flame front of the gas Bunsen burner. The optical density has a maximum peak value of 0.5 and an average density value of a maximum of 0.15. This CMP cable is usually installed in air return pressure boosting systems used in ventilation ducts or air handling equipment, and is approved for use in Canada and the United States. FEP / PLENUM materials that meet the UL910 standard have better flame retardancy than low-smoke halogen-free materials that meet the standards of IEC60332-1 and IEC60332-3, and the smoke concentration is lower when burned.


Mains-CMR (Riser Flame Test)

This is a UL standard commercial-grade cable (Riser Cable). The applicable safety standard is UL1666. The experiment stipulated that several samples were laid on the simulated vertical shaft, and the prescribed 154.5KW gas Bunsen burner (527,500BTU / Hr) was used for 30 minutes. Eligibility criteria are that the flame cannot spread to the upper part of a 12-foot-tall room. Trunk-level cables have no smoke concentration specifications and are generally used for vertical and horizontal wiring on the floor.


Commercial-CM (Vertial Tray Flame Test)

This is a general purpose cable in the UL standard and the applicable safety standard is UL1581. The experiment stipulated that a plurality of specimens were laid on a vertical 8-foot-high stand, and the prescribed 20KW ribbon torch was used to burn (70,000 BTU / Hr) for 20 minutes. The acceptance criterion is that the flame cannot spread to the upper end of the cable and extinguish itself. UL1581 is similar to IEC60332-3C, except that the number of cables is different. Commercial-grade cables have no smoke concentration specifications, and are generally only used for horizontal wiring on the same floor and not for vertical wiring on the floor.


General-CMG (Vertial Tray Flame Test)

This is a general purpose cable in the UL standard and the applicable safety standard is UL1581. Commercial and general-purpose test conditions are similar, and both are approved for use in Canada and the United States. General-purpose cables have no smoke and concentration specifications, and are generally only used for horizontal wiring on the same floor, and not for vertical wiring on the floor.

 

Home-CMX (Vertial Wire Flame Test)

This is the UL standard Restricted Cable. The applicable safety standard is UL1581-VW-1. The test stipulated that the sample should be kept vertical, and burned (30,000 TU / Hr) with the test torch for 15 seconds, then stopped for 15 seconds and repeated 5 times. The eligibility criteria are that the remaining flame must not exceed 60 seconds, the sample must not burn more than 25%, and the surgical cotton pads on the bottom cannot be ignited by falling objects. UL1581-VW-1 is similar to IEC60332-1, except that the burning time is different. This grade also has no smoke or toxicity specifications and is only used in home or small office systems where a single cable is installed. This type of cable should not be laid in bundles and must be sleeved.


The safety performance based on flame retardant wires is greater than ordinary wires. Nowadays, flame retardant wires have been widely used.

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