1. The composition of the switch cabinet:
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 layout has two structures: “pin” shape or “1″ shape
2) Circuit breaker room
3) Cable room
4) Relay and instrument room
5) Small busbar room on the top of the cabinet
6) Secondary terminal room
★ Electrical components in the cabinet:
1.1. Commonly used primary electrical components (main circuit equipment) in the cabinet include the following equipment:
Current transformer is referred to as CT [such as: LZZBJ9-10]
The voltage transformer is referred to as PT [such as: JDZJ-10]
Grounding switch [such as: JN15-12]
Lightning arrester (resistance-capacitance absorber) [such as: HY5WS single-phase type; TBP, JBP combined type]
Isolating switch [such as: GN19-12, GN30-12, GN25-12]
High voltage circuit breaker [such as: less oil type (S), vacuum type (Z), SF6 type (L)]
High voltage contactor [such as: JCZ3-10D/400A type]
High-voltage fuse [such as: RN2-12, XRNP-12, RN1-12]
Transformer [e.g. SC(L) series dry transformer, S series oil transformer]
High voltage live display [GSN-10Q type]
Insulation parts [such as: wall bushing, contact box, insulator, insulation heat shrinkable (cold shrinkable) sheath]
Main bus and branch bus
High voltage reactor [such as series type: CKSC and starter motor type: QKSG]
Load switch [e.g. FN26-12(L), FN16-12(Z)]
High-voltage single-phase shunt capacitor [such as: BFF12-30-1] etc.
1.2. 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.
2. Classification of high voltage switch cabinets:
2.1. According to the installation method of the circuit breaker, it is divided into removable type (handcart type) and fixed type
(1) Removable or handcart type (indicated by Y): It means that the main electrical components (such as circuit breakers) in the cabinet are installed on the handcart that can be withdrawn, because the handcart cabinets are well interchangeable Therefore, it can greatly improve the reliability of power supply. Commonly used types of handcarts are: isolation handcarts, metering handcarts, circuit breaker handcarts, PT handcarts, capacitor handcarts and handcarts used, such as KYN28A-12.
(2) Fixed type (indicated by G): Indicates that all electrical components (such as circuit breakers or load switches, etc.) in the cabinet are fixedly installed, and fixed switch cabinets are relatively simple and economical, such as XGN2-10, GG- 1A etc.
2.2. Divided into indoor and outdoor according to the installation location
(1) Used indoors (indicated by N); it means that it can only be installed and used indoors, such as KYN28A-12 and other switch cabinets;
(2) Used outdoors (indicated by W); it means that it can be installed and used outdoors, such as XLW and other switch cabinets.
3. According to the cabinet structure, it can be divided into four categories: metal-enclosed armored switchgear, metal-enclosed compartmental switchgear, metal-enclosed box-type switchgear, and open-type switchgear
(1) Metal-enclosed armored switchgear (indicated by the letter K) The main components (such as circuit breakers, transformers, bus bars, etc.) are installed in the metal enclosures of the grounded compartments separated by metal partitions. Switch equipment. Such as KYN28A-12 type high voltage switch cabinet.
(2) Metal-enclosed compartmental switchgear (indicated by the letter J) is similar to armored metal-enclosed switchgear, and its main electrical components are also installed in separate compartments, but have one or more of a certain degree of protection Non-metallic partition. Such as JYN2-12 type high voltage switch cabinet.
(3) Metal-enclosed box-type switchgear (indicated by the letter X) The shell of the switchgear is a metal-enclosed switchgear. Such as XGN2-12 high voltage switch cabinet.
(4) Open switchgear, no protection level requirement, part of the shell is open switchgear. Such as GG-1A (F) high voltage switch cabinet
Post time: Sep-06-2021