1、 Product Overview

When there is a fault in the T-connected branch line of 10KV overhead distribution line or the end user, the outgoing switch of the substation will trip because the protection action time limit of the incoming switch cannot be reasonably adjusted in coordination with the protection time limit of the outgoing switch of the substation. If the fault is permanent and the substation reclosing will not be successful, a local accident within the medium voltage user boundary will cause the power failure of the entire 10KV distribution line. If a user boundary switch (commonly referred to as watchdog) is installed at the T-junction or user terminal (responsibility boundary point), the fault (over-current, short circuit, single-phase grounding and other faults) in the user boundary is confirmed after judgment, and the fault is automatically isolated, then the user in the non fault area can be guaranteed to be in common use. ZW20A-12F outdoor user boundary vacuum circuit breaker is a user boundary switch independently developed by our company. It is mainly composed of ZW20A-12F outdoor pole mounted vacuum circuit breaker body, FDR-02 fault detection controller and external voltage transformer, which are electrically connected through aviation socket and outdoor sealed control cable. It has fault detection function, protection control function and communication function, can reliably judge and detect milliampere zero sequence current and interphase short circuit fault current within and outside the boundary, and can automatically remove single-phase ground fault and interphase short circuit fault. ZW20A-12F outdoor pole mounted vacuum circuit breaker is an outdoor power distribution equipment with the rated voltage of 12KV and three-phase AC 50Hz. It uses vacuum arc extinguishing and SF6 gas as the insulation medium. The box adopts the gas sealing, explosion-proof and insulation structure technology introduced from VSP5 of Toshiba, Japan. The sealing performance of the incoming and outgoing line bushings has also been improved. The overall sealing performance is excellent. The SF6 gas filled in the box does not leak and is not affected by the external environment; Its spring operating mechanism has been miniaturized and optimized for reliability and stability. With the adoption of the direct chain main drive and multi-stage tripping system, its action reliability and stability are several times higher than those of the traditional spring operating mechanism in China; The contact between the shaft and the sleeve of the main circuit adopts the internal retraction and external tension type watch chain structure. The contact resistance of the main circuit is small and the temperature rise is low. ZW20A-12F outdoor column mounted user high-voltage vacuum boundary breaker is a maintenance free product. It is a high-quality product among outdoor high-voltage vacuum boundary breakers. It is a new product developed by our company by combining the advantages and disadvantages of column mounted switches at home and abroad.

2、 This product mainly conforms to the following national standards:

Switch part: GB1984

High Voltage Alternating Current Circuit Breaker GB/T11022-1999

Common Technical Conditions for High Voltage Switchgear Control and Equipment Standards Control Terminal Part: GB/T726-2000

Basic Test Methods for Relays and Devices GB/T17626-1998

Electromagnetic Compatibility Testing and Measurement Techniques Electrical Fast Transient Burst Disturbance Test

3、 Environmental conditions

1. Ambient air temperature: - 40 ℃~+40 ℃; Daily temperature: the daily temperature change is not greater than 25 ℃; According to the nature of SF6 gas substance, when the ambient temperature is - 40 ℃, if the air pressure inside the box is 0.05Mpa, SF6 is still in the gaseous state to ensure the normal operation of the product. (When the ambient temperature is - 40 ℃ and the gauge pressure is 0.05Mpa, the SF6 liquefaction point is - 55 ℃; when the gauge pressure is zero, the SF6 liquefaction point will not exceed - 60 ℃).

2. The wind speed is not more than 35m/s;

3. No risk of inflammability and explosion. Places with strong chemical corrosives (such as various acids, alkalis or smoke) and violent vibration.

4. Altitude: ≯ 3000m;

5. Cover thickness: 10mm;

6. Air pollution degree: Grade IV;

7. Seismic intensity: ≯ 8;

8. Neutral grounding mode of power grid: neutral point is not grounded, neutral point is grounded through arc suppression coil, and neutral point is grounded through low resistance.

4、 Items specified by the user when ordering

1. Product model, name, parameter and communication mode;

2. Transformer ratio and accuracy class;

3. Quantity and delivery date;

4. Name and quantity of spare parts;

5. Other special operation requirements, such as contacts, accessories, etc;

6. Product certificate (including PT, CT and zero sequence transformer);

7. Installation and operation instructions;

8. Packing list;

9. Schematic diagram of product secondary wiring.