Key issues for selecting prefabricated branch cables

A prefabricated branch cable with good quality must be a mine cable with excellent performance. For domestic products, the conductor performance, insulation performance, mechanical physical properties of the material should meet the GB12706-91 standard - because the performance of the cable is prefabricated Basic indicators of branch cable products.

The prefabricated branch cable is a series of special production equipment in the factory according to the specifications of the main and branch cables required by the cable user, branch cable, length, branch position, etc. The branch cable is manufactured on the production line.

The performance of branch connectors is critical, which is the key performance of prefabricated branch cables. The branch coupling body connects the main cable and the conductor of the branch cable together, and is insulated and moisture-proof. From an external point of view, there is no way to know the quality of the internal joints. There are two important tests that can test the performance of the joints, namely contact resistance and thermal cycling tests.

The ratio of the contact resistance to the reference resistance of the isochronous branch cable R1/R2 (R1: contact resistance of the contact, R2: reference resistance of the branch cable) ≤ 1.2; for the thermal cycle test, when the main cable and the branch cable respectively pass the rated operating current, Heating for 5 hours, natural cooling for 3 hours into a cycle, a total of 125 cycles, after the 25th cycle, the surface temperature of the coupling does not exceed 75 °C, after each cycle, the surface temperature of the joint can not be compared with the surface temperature value of the 25th cycle 8°C high.

Resistance, because of the material's hindrance to the current, so called its resistance material. Resistance will cause changes in the flux of electrons, the smaller the resistance, the greater the flux of electrons, and vice versa. Substances with little or no electrical resistance are called electrical conductors, or conductors for short. The substance that cannot form current transmission is called an electrical insulator, or an insulator for short. The YFD series of prefabricated branch cables have been tested by the National Mine Cable Quality Supervision and Inspection Center. The contact resistance R1/R2 is 0.7, and the 25th thermal couple surface temperature is 43°C<75°C, and the 26th to 125th highest temperature is 47 °C<51°C.

Thermal cycling refers to the work cycle where heat is passed from one part to another. In a reactor, the heat transfer circuit is usually separated from the power to prevent the liquid from becoming radioactive after passing through the heat transfer circuit and contaminating its power circuit.

The key to deciding the performance of the branch coupling body lies in the material and process of the branch coupling body. For the majority of designers, it should pay full attention to the cable quality of the prefabricated branch cable , the material selection of the joint, and the production process and tooling.