Load Break Switch




  • The Load Break Switch for overhead lines is divided into SF6 or solid insulated type depending on an insulation method.
    Also, it is divided into motorized type (operated by electrical signal) and manual type (operated by the operator).
  • The Motorized LBS is equipped with voltage and current sensors to monitor distribution networks.
  • The LBS is structured to be operated by a driver with a single spring, and has constant opening and closing time.
  • For SF6 insulated type, materials with excellent electrical properties are used at the tulip type contact point, and thus, high mechanical and electrical operation characteristics, and stability are achieved.


Ratings 11kV 24kV 36kV
Applied Standard IEC60265-1, or IEC62271-103
Rated Voltage(kV) 17.5 25.8 36
Rated Current(A) 630 630 630
Rated Frequency(Hz) 60/50 60/50 60/50
Rated Short-Time Current(kA) 16, 3sec 16, 3sec 16, 3sec
Rated Making Current(kAp) 40 40 40
Rated Power-frequency withstand Voltage(kV) 50 60 70
Impulse withstand Voltage(kV) 110 150 170
Operating Mechanism Motorized
Insulating Medium SF6 gas
Bushing Material Porcelain/Polymer

Main Functions

  • Open/Closed for the main contact is electrically or manually possible.
  • The tank has built-in voltage sensors to measure voltage of each phase on source side and load side.
  • On each phase, the current sensor to measure currents is built-in to the tank.
  • The position indicator indicates the main contact position.
  • For Gas Insulated type, gas pressure status is shown on the indicator. When gas low occurs, all electrical and mechanical operations on the LBS are inhibited.
  • All operations on the LBS can be inhibited through the locking device.
  • The operating lever is provided to operate the LBS by using the hook stick.
  • The LBS and the Control are connected through a single cable.
  • The additional auxiliary contact is provided for the main contact position.
  • The gas emitting device is provided to prevent explosions when internal arc occurs.
  • Installation frames or brackets are provided to enable single/double poles or frame mounting.


  • Use as the Switch to make & break loads that is below the rating at trunk lines.
  • Installed with the Recloser, use as the Switch to perform sectionalizing function at trunk and branch lines, or customers at line end
  • Use as the Switch for Load Shedding to maintain the power quality at the point of the branch lines or customers
  • Use as the Switch to connect the two lines at the normally open point. This Switch is open loop network, but applied to the radial network, which has an alternate source.