Product Introduction
With the rapid development of China's power industry, when the reclosing operation was proposed in the 1970s and 1980s, the time required to close the contacts for the second time to open them was defined as the "golden short time". To ensure the breaking capacity of the second "opening" during reclosing, according to the requirements of the power industry standard DL/T755 "Guidelines for Safety and Stability of Power Systems", the short circuit time of high-voltage circuit breakers should not exceed 60ms. It is recommended to use 40 to 55ms, which can allow the arc extinguishing chamber to have sufficient time to change from the closing process to the state required before opening. State Grid requires that the short-circuit control of circuit breakers be achieved through reliable measures taken by the circuit breakers themselves. The opening and closing instructions of high-voltage circuit breakers are issued by the auxiliary switches configured in their operating mechanisms. Therefore, the auxiliary switches are ideal and reliable mechanisms for short-circuit control. This switch takes the FK switch as its main body. While inheriting the advantages of the FK switch such as large rated current, strong breaking capacity, flexible and diverse contact angles, and high temperature resistance, it adopts a mechanical structure that is ingenious.
Switch selection
12K12B 25K25K
Application equipment
Hydraulic mechanism
Environmental conditions
1.Ambient temperature: -40℃ to +80℃;
2. Altitude: No more than 5,000 meters;
3. Humidity: The average relative humidity within 24 hours shall not exceed 95%. The average pressure of water vapor does not exceed 2.2KPa. The monthly average relative humidity shall not exceed 90%. The average pressure of water vapor does not exceed 1.8KPa.
4. The vibration acceleration shall not exceed 15m/s ²;
5. The surrounding air is not significantly polluted by dust, smoke, corrosive or flammable gases.
Working principle
The FK auxiliary switch with delay function is based on the FK switch by adding a delay function module at the tail of the FK switch. This module drives the connection and disconnection of two normally open contacts. When the switch shaft rotates 95° from the open position, the ordinary normally open contact is connected, and at the same time, the delay module is triggered. After a delay of 13 to 26mm, The two normally open contacts driven by the delay module are connected, providing a guarantee for the short-time control of the circuit breaker.
Switch structure
This switch is composed of multiple units with the same structure. The moving contact piece is made of high-quality phosphor bronze, the moving contact is made of silver alloy, the fixed contact piece is made of copper plated with silver, and the insulating sheet is made of high-quality BMC material that is flame-retardant and heat-resistant, featuring high strength and good insulation performance. Reliable control of the delayed connection time of special contacts is achieved through the delay function module.
Wiring method
Insertion and crimping
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