The QJGR Series Flame-proof and Intrinsically-safe High Voltage Vacuum Soft Starter for Mining Applications is a new type of high-tech electrical equipment designed using third generation digital microprocessor control technology and modern thyristor technology. It is a specialized piece of equipment for the soft start of large high-voltage motors, providing the best voltage reduction and current limiting soft start mode for the motors, and mainly used for starting up and shutting down asynchronous motors. Structurally, the device is composed of a main vacuum contactor, fuse, control transformer, control module, high-voltage thyristor module, thyristor protection components, signal acquisition and processing components, and high-voltage vacuum bypass contactor.

1. Overload protection;

2. Overload and underload protection;

3. Over-voltage and under-voltage protection;  

4. Phase loss protection;

5. Three-phase unbalance protection;

6. Phase sequence protection;

7. Zero-sequence protection;

8. Thyristor over-temperature protection;

9. Wiring error protection;

10. Start Inhibit protection;

11. Long start protection;

12. Bypass contactor fault protection;

13. External fault input;

14. Locked rotor protection;

15. Door open lockout.

16. Time overcurrent protection

17. Short circuit protection