The composition of the switchgear
Feb 28, 2021
The switchgear shall meet the relevant requirements of the GB3906-1991 "3-35 kV AC Metal-enclosed Switchgear" standard. It is composed of a cabinet and a circuit breaker, and has functions such as overhead incoming and outgoing wires, cable incoming and outgoing wires, and bus connection. The cabinet is composed of a shell, electrical components (including insulators), various mechanisms, secondary terminals and connections.
Cabinet material:
1). Cold rolled steel plate or angle steel (for welding cabinet);
2) Al-Zn coated steel sheet or galvanized steel sheet (used for assembling cabinets).
3).Stainless steel plate (non-magnetic).
4). Aluminum plate ((non-magnetic).
The functional unit of the cabinet:
1). Main busbar room (generally the main busbar is arranged in two structures of "product" shape or "1" shape 2). Circuit breaker room 3). Cable room 4). Relay and instrument room 5). Cabinet roof small bus room 6). Secondary terminal room
Electrical components in the cabinet:
1. Commonly used primary electrical components (main circuit equipment) in the cabinet include the following equipment:
Current transformer referred to as CT
Voltage transformer referred to as PT
Earthing switch
Lightning arrester (resistance-capacitance absorber)
Isolation switch
High voltage circuit breaker
High voltage contactor
High voltage fuse
transformer
High voltage live display
Insulation parts [such as: wall bushing, contact box, insulator, insulation heat shrinkable (cold shrinkable) sheath]
Main bus and branch bus
High voltage reactor
Load switch
High-voltage single-phase shunt capacitors, etc.
2. The main secondary components commonly used in the cabinet (also known as secondary equipment or auxiliary equipment, refer to the low-voltage equipment that monitors, controls, measures, adjusts and protects the primary equipment), the common ones are the following equipment:
1. Relay 2. Electricity meter 3. Ammeter 4. Voltage meter 5. Power meter 6. Power factor meter 7. Frequency meter 8. Fuse 9. Air switch 10. Change-over switch 11. Signal lamp 12. Resistance 13. Button 14 . Microcomputer integrated protection device and so on.
