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Time: 2017-02-17

The new national standard GB 31247-2014 "classification of the combustion performance of cables and optical cables" not only evaluates the carbonization height of cables, but also requires the assessment of the heat release and smoke generation characteristics of cables. Flame retardant cables with traditional structure are difficult to pass the B1 test of GB 31247-2014 combustion performance classification due to many combustiables in each component of cables and no good isolation measures. Isolated flame-retardant cable technology has been improved, successfully passed the B1 level assessment, I believe it will soon be widely used.

The national standard GB 31247-2014 "classification of combustion performance of cables and optical cables" will be officially implemented on September 1, 2015. According to the international standard, the flame retardant grade will be divided into A, B1, B2 and B3 from A, B, C and D. Class A is non-combustible, that is, the cable whose outer sheath is metal sheath, such as MI cable; B3 is non-flame retardant, such as VV, YJV, etc. Grade B1 and B2 are flame-retardant cables with an application amount of ****. They should be selected according to the importance of the place where they are used. For high-rise buildings and places with dense personnel, grade B1 flame-retardant cables should be selected. This classification standard redefines the flame retardant level, and puts forward new requirements for the flame retardancy of cables, as well as new requirements for the manufacturing and design selection of cables.

New eu rules on fire retardant cables in buildings to be enforced after 01 December 2016:

CPR (European regulation 305/2011) is the full name of the European construction product regulation, which aims to ensure the effectiveness and efficiency of the relevant market of the European Union by clearly stipulating the performance requirements of construction products. The regulation took effect in April 2011 and officially replaced CPD (construction product directive) in July 2013.

CPR specifies that fixed and installed power, control, and communication cables in buildings are covered by this code, with the primary concern being the safety and fireproof performance of the cable product.

The specific requirement is that only products with the assessment report of the designated testing agency on the combustion grade test can be sold in the eu construction product market.

Since the reference standard EN 50575 for the assessment of combustion grade was finally issued in July 2015, the requirements for the CPR cables will be enforced after the transitional period of December 1, 2016. If the manufacturers do not have the relevant documents and combustion rating assessment report, they will not be able to sell their cable products in the construction product market in the eu region after the end of the transition period, which will undoubtedly greatly affect the majority of cable manufacturers.

The introduction of CQC flame retardant cable combustion performance certification for construction projects is the first step to follow the eu's mandatory measures:

At present, a number of domestic construction codes have made provisions on the use occasions and requirements of flame retardant cables. However, the existing certification rules are not clear in grading, there is no assessment of the heat release index of cable combustion, the lack of grading certification of combustion performance and other issues need to be refined and improved. With the promulgation and implementation of the national standard GB 31247-2014 "classification of the combustion performance of cables and optical cables", China quality certification center (CQC) and the national fire prevention building materials quality supervision and inspection center jointly issued the fire retardant cable combustion performance certification rules for construction projects in accordance with the national standards. The combustion performance of cables used in construction engineering is graded according to product structure, combustion grade and product standard certification:

Class A is non-combustible cable

Class B1 is flame retardant class 1 cable

Class B2 is flame retardant class 2 cable

Therefore, it is necessary for domestic cable manufacturers and upstream material suppliers to attach great importance to this reform

With the increasing dependence of social production and people's life on electricity, a large number of rubber-plastic insulated wires and cables are used in various construction projects, which not only transmit electric energy and improve the building function, but also bring challenges to the building fire safety. It is one of the effective countermeasures to develop various high performance flame retardant cables and strengthen their application in engineering. Therefore, it is of great significance for building fire safety to understand and promote the manufacturing application and inspection and certification of flame retardant cables.