The high-voltage load break switch (HV LBS) is an electrical device positioned between a high-voltage circuit breaker and a high-voltage disconnecting switch. Often used in series with a high-voltage fuse, it controls power transformers. Equipped with a simple arc-extinguishing mechanism, the HV LBS can switch certain load and overload currents but cannot interrupt short-circuit currents. For this reason, it is typically paired with a high-voltage fuse for short-circuit protection.

Installation Requirements for High-Voltage Load Break Switches:

1. Blade Alignment:
   The switch blade must align precisely with the fixed contact to ensure proper contact.

2. Phase Contact Timing:
   For a 10kV high-voltage load break switch, the blades of all phases must contact their fixed contacts simultaneously, with a tolerance of no more than 3 mm.

3. Pulling Distance:

   • For outdoor high-voltage column load switches: the pulling distance should exceed 175 mm.
   • For indoor compressed air load switches: the pulling distance should be 182 ± 3 mm.

4. Fixed Contact Orientation:
   The fixed contact of the load switch should typically connect to the power supply side. When installed vertically, the fixed contact should be on the upper side.

5. Transmission Components:

   • The transmission parts of the load switch must be free of cracks or damage, operate flexibly, and include a protective ring or sleeve for the tie rod.
   • Components such as extension shafts, bearings, couplings, and cranks must have adequate mechanical strength. Connecting rod shaft pins must not be permanently welded.

6. Cable Connections:
   For wall-mounted load switches, the connection to the incoming cable should pass through a busbar.

Applications and Common Models:

• Indoor MV LBS: Models such as 12kV, 24kV, and FN7 are common.
• Outdoor LBS: Models include FZW32 and SF6 LBS, suited for outdoor applications.