LV switchgear: functions and selection

The three basic functions provided by low voltage switchgear for the related electrical circuit are:

• Electrical protection
• Isolation
• Local or remote switching

This chapter explains these functions, describes the most common types of low voltage protection and/or control switchgear. With a special focus on circuit-breakers: their characteristics, and how to select circuit-breakers, taking into account selectivity and cascading techniques.

Chapter H - Contents

• The basic functions of LV switchgear
  • LV switchgear functions - Electrical protection
  • LV switchgear functions - Isolation
  • LV switchgear functions - Switchgear control
• The switchgear
  • Elementary switching devices
  • Combined switchgear elements
• Choice of switchgear
  • Switchgear selection
  • Tabulated functional capabilities of LV switchgear
• Circuit-breaker
  • Standards and description of circuit-breakers
  • Fundamental characteristics of a circuit-breaker
  • Other characteristics of a circuit-breaker
  • Selection of a circuit-breaker
  • Coordination between circuit-breakers
  • Selectivity MV/LV in a consumer’s substation
  • Selectivity of Residual Current Devices (RCDs)
• Maintenance of low voltage switchgear

ru:Низковольтная распределительная аппаратура