cable news: the influence of the structure of refractory cable on the fire resistance-非凡电子娱乐

due to the insulation and sheath of wire and cable,

generally made of plastic or rubber and other combustible materials.

with the increase in the amount of wire and cable short circuit and other reasons for the greater the probability of fire.

in the event of a fire, a large amount of smoke produced by the burning of the wire and cable,

not only to reduce the visibility of the fire, the impact of personnel fled the scene of the fire,

and the smoke is irritating, narcotic, causing suffocation to the human body,

poisoning, or even death, causing major economic losses and casualties.

in the national standard, the characteristics of fire resistant wire and cable have been clearly defined.

gb12666.6-91 specifies the fire resistance of fire-resistant cable:

class a: the flame temperature is 950~1000 deg c, the duration of the fire is 90min, no breakdown;

class b: flame temperature of 750~800 deg c, continuous fire time 90min, no breakdown.

however, the market is now refractory steel wire and cable quality uneven,

impact on the use of fire-resistant wire and cable.

how can we ensure that the products meet the standard requirements of the fire performance indicators?

it is a very important factor to select the mica tape with good fire resistance.

a class of synthetic mica tape is more suitable, refractory b class can choose natural gold mica tape.

however, the same mica tape,

why do some manufacturers of fire-resistant cable can not pass the fire test?

in addition to the process, equipment for reasons,

special attention should be paid to the influence of the winding structure on the fire resistance.

insulated wire core after the cable generally need to wrap around the glass ribbon, pvc belt or non-woven belt as reinforcement,

to keep the structure of the cable to be round. if the selection is not suitable for wrapping tape,

fire resistance of refractory cable. using the same mica tape layer and the cladding structure,

wrapped around the cable wrapped with non-woven tape or pvc tape can be tested by fire,

however, wrapped around the fire with fire retardant properties of glass ribbon or mica tape is not necessarily through the fire test.

we designed the use of coated glass ribbon and mica tape as the purpose of wrapping the cable,

is to use their fire resistance to improve the fire resistance of the cable,

however, the test results show that the fire resistance is decreased.

how does the wrap around cable affect the fire resistance of the cable?

refractory cable insulation materials generally use pvc, pe, xlpe, etc..

under the condition of high temperature combustion at 750 deg c, the insulating layer of the cable basically does not exist,

the insulation layer is designed to ensure the electrical properties of the cable under normal conditions and the protection of the refractory layer,

the fire resistance of the cable is not determined, but the influence of the insulation state on the refractory layer should be taken into account in the high temperature combustion.

if the cable is wrapped around a layer of the non-woven fabric or pvc belt, it is burned with the insulation,

the stress deformation caused by the temperature fluctuation has enough space to diffuse outward,

the damage of the refractory layer is small, so it has little influence on the fire resistance.

if the cable wrapping layer is coated with glass ribbon or mica tape, because the cladding layer has a certain fire resistance,

because of the fire resistance of the cladding layer, the insulating material is not directly contacted with the flame when burned,

instead of melting. due to the tightening of the cladding layer,

the stress and deformation produced by the melting of insulation material can not be released outwards,

the refractory layer is subjected to large impact force. and if the cable is armoured,

when the temperature changes, the stress and deformation of the steel strip are also applied to the refractory layer,

this makes the refractory layer suffer more damage, so it is difficult to pass the fire test.

fire resistant cable can play an important role in the fire, is vigorously promoting the use of important places,

in order to ensure that the fire retardant cable should play its due role, the cable manufacturer must guarantee the quality of the refractory cable.

the wrapping structure of fire-resistant cable has an influence on the fire resistance. if the choice is not proper, the fire resistance will decrease.

from the point of view of reducing cost, non - low - smoke - resistant cable can be made of non - woven fabric.