6kV Mining Flameproof and Intrinsic Safety Vacuum AC Soft Starter QJGR-250/6
Functions: This product is mainly used in underground coal mines, where there are mixed explosive gases, such as methane. It is used to control and protect the motors frequently started in the power system, which is 3-phase neutral point ungrounded, with rated voltage 6kV, rated frequency 50hz and rated current up to 250A.
It is functional and reliable and it can precisely step up the starting current so as to diminish the damage to the power system with soft start and soft stop. Remote control, on-site control and fast open structure are available.
Operation Principle: Thyristors are connected in series and are micro-computer controlled so as to adjust the voltage gradually and smoothly. It is composed of explosion-proof enclosure and functional core. The silicon control rectifier and contactor can be drawn out for maintenance. The front door is half fast-open type. Its self-inspection function helps to protect the power system from the damage of over current, under current, short circuit, earth leakage, under voltage, over voltage, loss of phase, neutral grounding and etc. Technical Parameters: Rated Voltage: 6kV Rated Frequency: 50hz Rated Current: 250A, 150A, 50A Rated breaking current: 2000A Rated making current: 2500A Max breaking current (25 times): 2500A Rated short-time withstand current/ period: 2500A, 2s Rated short-time peak withstand current/period: 6250A, >0.3s