The mine explosion proof dry type transformer use in explosion hazard area. This kind of transformer usually make dry type transformer. The main structure is all joint surfaces made according to the requirement of flameproof which can bear 0.8MPa of inner pressure
The principle of mine explosion proof dry type transformer change the voltage by electromagnetic induction. There are 2 sets of coils in transformer. They are a primary side coil and a secondary side coil. In normal the secondary coil is inside of the primary side coil. When a coil side connect to alternating current, the coil of transformer produce alternating magnetic field the secondary coil side will produce induced electromotive force. The ratio of turns of transformer’s coils is equal to the voltage ratio.
The capacity of mine dry type transformer usually has 4 kilovolt ampere and 2.5 kilovolt ampere which is specially used for power supply of electric drill, lighting, signal and other equipment.Its incoming and outgoing wires are drawn by the cable through the outgoing sleeve.The primary voltage is 380 volts and 660 volts.The side voltage is generally 133 volts.The flameproof transformer with the capacity above 100 kva is often combined with the flameproof switch box to form the flameproof mobile substation.Its output voltage is 400 volts, 690 volts and 1200 volts to meet the needs of mine electrical equipment.In order to adapt to tunnel transportation, transformer structure height is required to be low.In this way, the iron column diameter can be larger, generally using cold rolled silicon steel sheet.Insulation of 100 kva and above is usually grade H.
