Scope and purpose 
 KBZ9 series flameproof vacuum feed switch for containing explosive gas (methane) mixture of the coal mine, in the AC 50HZ, voltage to 660/1140V, current 200-400A power supply line, as a power supply system switch the master switch or branch, also can be used as a large capacity motor starting control is not frequently used. 
 Main Features 
 1, the feed switches have leakage latch, leakage protection, overload protection, short circuit protection and display and test functions 
 2, for the master switch with a leakage protection; as branch switches with power and direction selectivity