What is a mineral-insulated, non-combustible cable?-Guangdong Yongyi Zhujiang Wire & Cable Co., Ltd. – A manufacturing enterprise specializing in the production of wires and cables.

News

Home page

What is a mineral-insulated, non-combustible cable?

2020-01-03

On May 1, the latest edition of the "Code for Fire Protection Design of Buildings" GB 50016-2014, which has just been implemented, explicitly states: “Fire-fighting power supply lines should preferably be laid separately from other power supply lines in different cable shafts and trenches. If it is genuinely difficult to lay them separately and they must be installed in the same cable shaft or trench, they shall be arranged on opposite sides of the shaft or trench, and fire-fighting power supply lines must use mineral-insulated, non-combustible cables.” The implementation of this provision has redefined the crucial role of mineral-insulated, non-combustible cables in electrical fire protection applications in China, marking the day when these cables will increasingly replace fire-resistant, low-smoke, halogen-free cables—among others—in household electrical systems. This development will have a profound and far-reaching impact on the widespread adoption of mineral-insulated, non-combustible cables.

So, what exactly does “mineral-insulated non-combustible cable” refer to? The explanatory notes on page 377 of the new edition of the "Code for Fire Protection Design of Buildings" GB 50016-2014 state: “Mineral-insulated non-combustible cables consist of a copper core, mineral insulation material, and a metallic sheath made of copper or other metals. In addition to exhibiting excellent electrical conductivity, mechanical and physical properties, and fire resistance, these cables also possess outstanding non-combustibility. Under fire conditions, such cables not only ensure uninterrupted power supply for firefighting during the duration of the fire but also remain non-combustible and do not produce smoke.”

Is a mineral-insulated, non-combustible cable necessarily a BTTZ rigid copper-sheathed magnesium oxide mineral-insulated cable? Currently, relevant domestic organizations hold differing opinions on this issue, and there’s considerable debate ongoing. However, looking purely at the terminology, flexible mineral-insulated cables such as YTTW, NG-A(BTLY), and HFTGB available on the market today all appear to meet the relevant requirements stipulated in the new regulations. From a broader perspective, we can even boldly interpret this somewhat ambiguous wording as a prelude to yet-to-be-issued new standards and specifications—effectively leaving room and opportunities for the further development of flexible mineral-insulated cables, thereby demonstrating that flexible mineral-insulated cables are gradually gaining acceptance. After all, the regulations themselves do not explicitly specify whether rigid or flexible mineral-insulated, non-combustible cables should be used, nor do they clarify the materials or manufacturing processes that these cables must employ.

Although the current national standard GB/T 2900.10-2013, "Electrical Terms—Cables," and the industry standard JGJ 232-2011, "Technical Specification for Installation of Mineral-Insulated Cables," define only the BTTZ series of mineral-insulated cables, the term "flexible mineral-insulated non-combustible cable" as described in the new regulations appears to be applicable. As the number of successful domestic application cases continues to grow, the proportion of flexible mineral-insulated cables is steadily increasing, and it’s only a matter of time before relevant authoritative documents are issued.

BTTZ Cable Installation Instructions: Terminal Head Installation, Intermediate Connector Installation

What is the model number of fire-resistant wires and cables with a Class A combustion performance rating?