Classification of flame retardant grades of cables

Cable is an indispensable part of modern society, which is widely used in electric power, communication, transportation, construction, petrochemical and other fields. However, in the process of cable use, due to various reasons, fire accidents may occur, which will bring great threats to people's lives and property safety. In order to ensure the safe use of cables and prevent the occurrence of fire accidents, the classification standard of cable flame retardancy is formulated.

The flame retardant grade of cables refers to the combustion performance of cables under fire conditions, and is usually tested and evaluated by the international standard IEC60332. The standard divides the flame retardant grade of cables into three grades: A, B and C, of which A is the highest and C is the lowest.

operation sequence/order

1. Select test samples: randomly select 3 samples from the same batch of cables for testing.

2. Preparation before test: Leave the sample at 20 5℃ for 24 hours to make it reach room temperature.

3. Test method: Put the sample on the combustion device according to a certain length, ignite the lower end, and record its combustion time and length.

4. Evaluation results: According to the test results, the flame retardant grade of cables is divided into three grades: A, B and C, of which A is the highest and C is the lowest.

Classification of flame retardancy

Class A cable: In case of fire, the flame spread speed of the cable is extremely slow, the flame height is extremely low, the burning time is extremely short, and the burning length is extremely short.

Class B cable: In case of fire, the flame spread speed of cable is slow, the flame height is low, the burning time is short, and the burning length is short.

Class C cable: In case of fire, the flame of the cable spreads faster, the flame height is higher, the burning time is longer and the burning length is longer.