1.CM fire rating
CM is currently the most commonly used flame retardant level for cable cable. Its test standard is UL 1581. According to the definition, a small bundle of Cm-class cable cable will automatically go out within 5 meters of combustion diffusion.
At present, the outer sheath of CM-class cable network cables is mostly made of PVC and the insulation layer is made of high-density PE. When burned, it will emit toxic halogen, smoke and a lot of heat.CM-class cable is generally used for horizontal running on the same floor, and is commonly found in the United Kingdom, Asia and Australia.
2.CMR fire rating
The safety of the CMR fire rating is the second, which is mainly achieved by improving the ignition point of the cable to achieve the purpose of non-flammable. Its test standard is UL 1666. In the definition, under the condition of forced fan combustion, a bundle of CMR cable network cables must be extinguished within 5 meters of the combustion diffusion.
At present, the outer sheath of CMR class cable network cable is made of high flame retardant PVC material, and the insulation layer is made of high-density PE material. After flame combustion, it will emit toxic halogenated gas (chlorine gas) and lead vapor, which will quickly consume the oxygen in the air and make the flame go out.CMR class cabling is widely used in ventilation systems in mains that are physically separated from the cabling system, i.e. in the interior vertical mains subsystem, and is commonly found in Asia and Australia.
3.CMP fire rating
The CMP fire rating is the safest. It has perfect flame retardancy and does not emit large amounts of toxic smoke when burning.The CMP test standard is UL 910. According to UL definition, a bundle of CMP cable and network cables must extinguish themselves within 5 meters of the combustion diffusion under the conditions of forced intensive combustion by fans.
The outer sheath of CMP class cable wire is made of fluorine (such as PTFE PTFE, FEP fluorinated ethylene propylene), which has high decomposition temperature and ignition point.Because CMP cable network cable can stop the spread of the combustion, will send out to minimize smoke and toxin, even when there is a fire, nor in the building is full of a lot of burning due to cable network and smoke or harmful toxins, so grade CMP cable network cable is used in the ventilation duct or air handling equipment used air circumfluence pressurization system, common in Canada and the United States.
4.Dongguan Wenchang Electronic Co., Ltd. is a China manufacturer with CM, CMR, CMP certification.
CMR class (vertical combustion test) These are commercial grade cables in the UL standard. Safety standard is UL1666. There is no smoke density specification and they are generally used for floor vertical and horizontal wiring.
CMP class (Stei Sodium Duct Test) is the most required cable in UL fire safety standard. It is usually installed in air reflux pressurization systems used in ventilation ducts or air handling equipment. It is approved in Canada and the United States.
5.Differences between CM, CMR and CMP:
CM, CMR and CMP differ in fire rating, combustion situation and outer sheath material. In addition, they differ greatly in price and application area.
(1)The difference in price.
The outer sheath of CM cable and CMR cable is made of PVC material, while the CMP cable is made of fluorine material, so the price of CMP cable is much more expensive than that of CM cable and CMR cable.
(2) Differences in application areas
In general, CM cable is used in the horizontal wiring of building lifts and inflatable rooms in other environments, CMR can be used in the vertical wiring of building lifts and vertical passages, and CMP can be used in the horizontal wiring of air ducts, inflatable rooms or other air circulation environments.
Post time: Aug-27-2020