... PurposeBXB- /3300(1140,660)Y series apply to low-voltage protection box containing methane gas and coal dust mixed with ... and below Mining Explosion-proof mobile substations, low-voltage distribution switches, low voltage side of the common fault breaking, high ... leakage, and leakage atresia, overvoltage, under voltage, tripping and other backup protection;Protect me divided into two loops bilateral ...