The concept of mineral insulated cables
1, concepts or definitions
National standards GB/T13033 - 2007, "mineral insulated cables and terminals under rated voltage 750V and below" (Part 1) are not defined.
2, the Ministry of housing and urban standard JG/T313 - 2011 "rated voltage 750V and below a mineral insulated cable and terminal" (People's Republic of China construction industry standard definition) is not suitable for BTTZ mineral insulated cable.
Specific to today's introduction, mainly in the national standard GB/T13033 - 2007, "rated voltage 750V and below mineral insulated cables and terminals" as the basis. Speak more specifically introduces the copper sheath insulation fireproof cable for Magnesium Oxide, "the main content of minerals laying rule cable laying technology project" -- JGJ232__2011 is Magnesium Oxide copper sheath insulation fireproof cable. It is defined as follows: copper with high conductivity is used as conductor; inorganic Magnesium Oxide is used as insulation; seamless copper tube is used as sheath; if necessary, a layer of plastic outer sheath is extruded outside the metal copper sheath. For example: Copper sheathed Magnesium Oxide insulated cable (BTTZ cable), is an outer layer made of seamless copper sheath, middle filling Magnesium Oxide crystal powder as insulation materials, is a new type of single stranded copper conductor cable. This definition is more narrowly defined than the last one.
3. Development of mineral insulated cables
Mineral insulated cable (Mineral Insulated Cable), referred to as MI cable. At present, according to the structural characteristics can be divided into two kinds of rigid and flexible.
Rigid mineral insulated cable (BTTZ) invented earlier, conceived at the end of the nineteenth Century Swiss engineer Arnold Borel proposed Francois mineral insulated cables, and obtained a patent in 1896, after 1934-1936 years, the British put into production quickly. China was also developed in 60s of last century. It began to be used in the fields of military, metallurgy and so on. In the middle of 80s, it began to industrialize and was gradually accepted by the construction field.
In 1991, China promulgated the "GB13033 rated voltage 750V and below the national standard of mineral insulated cable and terminal", but the corresponding design standards and norms in the formulation, revision of failed to keep up with, resulting in the use and promotion of the mineral cable in our country has been slow to develop, in application lags behind the developed countries. In recent years, in order to improve the safety level of the electrical circuit, and reduce the loss of electrical fire accidents, the Ministry of construction, Ministry of public security, some local governments have issued a code for electrical design, and clearly defined in some important places or electrical wiring should use mineral insulated cables, to further broaden the scope of application of mineral insulated cable.
4, the current standards and norms
GB/T13033 - 2007 National Standard for mineral insulated cables and terminals under rated voltage 750V and below. Instead of 1991 China promulgated the "GB13033 rated voltage 750V and below a mineral insulated cable and terminal" 09D101-6_ "standard; mineral insulated cable laying" instead of "99D101_6"; "mineral cable laying technology project" JG/T313 - 2011 "- JGJ232__2011; rated voltage 750V and below the mineral insulated cable and terminal".