A purpose 
 KBD-350 (200) / 660 (380) Flameproof Switch for feed gas mixtures containing methane, a dangerous coal mine explosion, AC 50Hz, rated voltage of 660V, 380V, rated current of 350,200 A of points not directly grounded in the power supply network, as the total power distribution switches, power distribution switch or as a motor branch infrequent start with. 
 Second technical features 
 1. Overload, short setting times can be, by adjusting the thermal relay setting; 
 2. Switch short circuit, overload protection, used in conjunction with the JJB-660/380 leakage protection can be achieved; 
 Three technical parameters 
 Rated voltage 
 (V) Rated current 
 (A) operating frequency 
 (HZ) closing mode 
 660,380 350,200 50 mechanical closing machinery to maintain