The high-voltage load break switch (LBS) is a combined high-voltage electrical device that includes an isolating switch, fuse, thermal relay, shunt release, and arc extinguishing mechanism.

Key Features and Functions:

1. Arc Extinguishing Capability:
   The high-voltage LBS is equipped with a simple arc extinguishing device, allowing it to make and break normal load currents. However, it cannot interrupt short-circuit currents independently.

2. Coordination with Protective Devices:
   To address short-circuit currents, the LBS is typically paired with a high-voltage fuse and a thermal release. The fuse interrupts the circuit during a short circuit, while the thermal release trips the load switch automatically in the event of an overload.

3. Isolation Function:
   When the LBS is open, it creates a visible isolation gap, ensuring safe disconnection of the power supply for maintenance purposes.

Applications:

The LBS is designed for three-phase AC systems (10 kV, 50 Hz) and is often integrated with power distribution equipment, such as:

• Ring network switchgear
• Compact substations
• Power distribution systems for area network construction, industrial and mining facilities, high-rise buildings, and public utilities

It can serve as a ring network power supply or a terminal, performing functions such as power distribution, control, and protection.

Advantages:

• Performance: High breaking capacity, reliable operation, long electrical lifespan, and suitability for frequent operation
• Compact Design: Small size, lightweight, and minimal maintenance
• Safety: Equipped with an isolation gap, overload protection, and phase-loss prevention
• Remote Control Capability: Features an electric spring mechanism for the grounding switch with closing ability

Classification:

1. By Arc Extinguishing Medium:

   • Gas-generating type
   • Compressed gas type
   • Vacuum type
   • SF6 type

2. By Installation Location:

   • Indoor type
   • Outdoor type

Application Scenarios:

The LBS is suitable for environments requiring oil-free, low-maintenance, and frequent operations. When paired with fuses, it can replace circuit breakers for small or low-priority loads. Selection is based on rated voltage and current, with verification for dynamic and thermal stability. If used with a fuse, only the breaking capacity of the fuse needs to be checked, eliminating the need for further stability verification.