US UL's Five Fire Ratings

US UL's five fire rating UL fire rating is divided into five types:

1, booster level. This includes CMP copper (UTP and ScTP) and OFNP or OFCP fiber optic cables, which are the highest grade cables. On a bundle of booster grade cables, when the fan is forced to blow to the flame, the spread of flame on the cable within 5m will self-extinguish. Moreover, due to the inclusion of chemicals, this type of cable does not emit toxic fumes or steam when it is burned or at extremely high temperatures. In the United States, booster grade cable is the preferred cable. In communication wiring, it is usually installed in the air return pressurization system used in ventilation ducts or air handling equipment.

2, trunk level. This includes CMR copper cables as well as OFNR or OFCR fiber optic cables and is the second-ranked cable. Bundled trunk level cables In the case of fan forced air blow, the spread of flame on the cable must be self-extinguishing within 5m, however, it does not have smoke or toxicity specifications. In other countries outside the United States, this fire rating is usually used in building trunks and horizontal cables.

3, commercial grade. This includes CM copper cables as well as OFN or OFC fiber optic cables. Commercial grade cables are of a lower class than the trunk grade. The spread of flame on bundled cables must be self-extinguishing within 5m, but there are no restrictions on fan forced air and no smoke or toxicity specifications. Commercial grade cables are commonly used for horizontal cabling and are generally bundled together.

4, general level. This includes CMG copper cables as well as OFNG or OFCG fiber optic cables. This level of cable performance is similar to commercial grade.

5, home level. This refers to the CMX copper cable, which has no fiber classification and is the lowest level of UL fire rating. The flame on a home-grade cable must extinguish itself when it reaches 5m, but there is no smoke or toxicity specification. Home-grade cables are generally only used in home or small office systems where each cable is laid separately. It should not be laid in bundles because the flame spread of bundled cables is very different from a cable.