The Mi cable is constructed entirely of inorganic materials. The outer metal sheath and insulated conductors enable the cable to endure the harsh impacts of fire while being fully operational afterward. Here are some requirements to make the MI cable:
Copper that is highly conductive-B5 or ASTM B4
Pure Magnesium Oxide (MgO)
A seamless Tube Cable
A continuous and maximum operating temperature of 250 ºC
Voltage of 0-300 volts AC/DC or 0-600 AC/DC
Factory test voltage of 1500 volts RMS (300-volt cable)
0.1% power factor
Dielectric constant (CIC) at 3.7
Dielectric strength (70 volts/ml at 475 ºC)
The cable is designed to offer users permanent solutions to difficult wiring problems. It is made to enable its users to experience the comfortable and permanent installation of electrical circuits.
According to the MICC, a MI Cable company, the process of manufacturing the MICC cable requires several procedures;
First, there has to be the best quality and pure Magnesium Oxide (MgO) powder. The powder is subjected to a melting point of 2800 C for it to be ideal for insulation.
Second, the pure MgO is turned into blocks. Unlike other companies, the MICC manufacture the full range of MI cable.
Thirdly, a seamless Copper Tube is used due to its optimal lifetime security and ability to withstand high pressure and stress. It is the perfect option for a fire-rated cable.
Then, the required number of conductors is added, together with the MgO blocks.
After that, the conductors and the MgO are inserted into the Seamless Tube Cable. The cable is then drawn through a die to make its diameter smaller and fit. The fine is highly tolerant to give quality via its unaltered geometry. Therefore, only cables with a perfect profile are produced.
Next, the cable is annealed to get rid of the sheath stress caused by the drawing process. The drawing and annealing processes are performed repeatedly until a cable with the perfect size is formed.
Here’s a video you can watch to understand MI cable manufacturing.
