1、 Purpose:

1. FN3-10, FN3-10R, FN3-10R/3 load heads are high-voltage electrical appliances of high-voltage devices of indoor devices. It is applicable to AC 50Hz, 6KV or 10KV networks for breaking and closing load and overload current. It can also be used for breaking and closing no-load long lines. Switch of no-load transformer and capacitor. The load switch with RN3 fuse (FN3-10R, FN3-10R/S) can cut off the short circuit breaker for protection switch.

2. The load switch can be operated with CS3 and CS2 manual operating mechanisms.

2、 This load switch is applicable to the following working environments:

1. The altitude shall not exceed 1000 meters;

2. The ambient air temperature is not higher than+40 ℃ and not lower than - 10 ℃.

3. Indoor places where the relative air humidity is not more than 90% (when the temperature is+25 ℃);

4. In the environment without conductive dust;

5. No corrosive gas objects that damage metal and insulation;

6. Places free from severe vibration and impact;

7. In the environment without combustion and explosion hazard.

4、 Structure:

The appearance of FN3-10 indoor load switch is similar to that of general indoor disconnector (Fig. 1). The bottom of the switch is frame 2, and the transmission mechanism is installed in it. The frame is mounted on it. The frame is equipped with six insulators. The upper three insulators 3 are used as supporting parts and cylinders. The piston is installed in the frame and driven by the main shaft. The lower three insulators only serve as supporting parts. The upper and lower insulators are equipped with contact bases. The conductive part is composed of the knife switch and the contact base. The knife switch 6 and the lower contact base 8 are fastened by six pieces of spring. The end of the knife switch is equipped with arcing contact 5, and the upper contact base 4 is the main static contact.

The main static contact is equipped with arc static contact 3 and arcing nozzle 1. The arc static contact and the main static contact are connected by two thin beryllium bronze sheets (see Figure 5).

Each phase blade is composed of two copper plates. The end and the main static contact are riveted with silver contacts. When the load switch is closed, the main circuit is in parallel with the arc-extinguishing circuit, and most of the current flows through the main circuit. When the load switch is opened, the main circuit is disconnected first, and the current only flows through the arc contact. At this time, sufficient compressed air has been generated in the cylinder. When the arc contact is disconnected to the nozzle, the nozzle also generates certain gas due to the contact between the arc and the nozzle. When the arc-extinguishing contact is just disconnected, these two kinds of air flows are strong heat arc blowing, Make the arc extinguish quickly.

The frame is welded by angle steel and steel plate (see Fig. 4a). The upper part of the frame is the main shaft 6. The auxiliary shaft 1 is driven by the tube 7, and then connected with the insulating pull rod 2 to make the blade move. A long hole is opened on the passenger 2. The tube is equipped with a quick closing spring 8. The auxiliary shaft is welded with a cam and closing movement. When the main shaft 6 rotates in a counterclockwise direction, the tube 7 moves downward. After moving for a short period of time, the cam is hooked with the trip buckle. When the tube 7 continues to move downward, the closing spring is compressed, and the blade does not move at this time, When the main shaft rotates to the end position, the tube 7 pushes the trip buckle to open the trip buckle and the cam, and the switch closes quickly. Two break springs 8 are installed in the middle of the frame.

The upper part on the left side of the frame is the opening oil buffer, and the lower part is the closing rubber buffer. The frame is provided with mounting holes (see Figure 1). Users can configure M16 bolts to fix the load switch. The crank arm can be installed on either side of the left or right end of the main shaft of the load switch, and there is a grounding screw M10 on the left side of the frame connecting the operating mechanism × 25。

Add a fuse (Figure 2) with the model of FN3-10R/S above the FN3-10 load switch or a fuse (Figure 1) with the model of FN3-10R below the FN3-10 load switch. The fuse is composed of frame, socket and fuse tube.

5、 Installation and adjustment:

1. The installation height of the load switch is generally 2.5 meters (the distance from the main shaft of the load switch to the ground). The installation position of the operating mechanism and the distance from the handle fulcrum to the ground shall not be less than 1.1 meters.

2. The load switch shall be installed on the vertical wall or metal frame. The switch shall be at the opening position during installation. The user can configure 4 M16 bolts to fix it by using the mounting holes on the frame at the beginning and bottom. When the load switch has a fuse, another 2-4 M16 bolts shall be prepared to fix the fuse.

3. Install insulating pull rod 8 on the switch as shown in Figure 1. The length of the pull rod shall be checked and adjusted after matching with the operating mechanism.

4. Before connecting the conductive bus with the terminal board of the switch, the contact surface should be filed and wiped with a fine file.

5. FN3-10, FN3-10R, FN3-10R/S. Three types of load switch. It can be used with any of CS3 and CS2 manual operating mechanisms. When the operating mechanism handle is up, the load start should be in the closing position. When the handle is downward, it should be the opening position.

6. The adjustment of load switch and CS3 operating mechanism shall be carried out according to the following steps:

(1) See Fig. 3 and Fig. 4. The connecting rod 3 between the load switch and the operating mechanism is 3/4 "welded steel pipe (provided by the customer). One end of the connecting rod 3 is welded with the curved crank arm 2 on the switch, and the other end is welded with the screw rod on the operating mechanism. The insertion depth at the welding point is not less than 25mm (for CS3 type). The length of the connecting rod 3 is determined by the customer.

(2) Determine the initial angle of the upper crank arm of the main shaft at the beginning of the load according to the adjustment.

(3) After the load switch and the operating mechanism are installed together, the rotation angle of the operating mechanism handle should match the rotation angle of the main shaft when the load switch is "open" and "close"

(4) When the switch is in the open and close position, the locating pin of CS3 type operating mechanism shall reliably lock the handle, and it cannot be operated without pulling out the locating pin.

7. The adjustment of load switch and CS2 operating mechanism shall be carried out according to the following steps:

(1) Place the operating mechanism in the split position, connect the connecting rod 2 (3/4 "welded steel pipe) with the connecting rod 1 on the transmission bearing and weld the bent crank arm on the main shaft of the load switch (the length of the connecting rod 1.2 must be determined by the customer).

(2) At the opening position, when the handle of the operating mechanism is pulled downward, the parts that have been tripped should be able to be buckled on the semicircle hook again. If the handle of the operating mechanism reaches the lower stop pin and is buckled prematurely, the connecting rod 1 must be shortened, otherwise, the connecting rod 1 must be lengthened.

(3) If a loss-of-voltage release is installed and the test is conducted without voltage, the ram of the loss-of-voltage release must be pressed down, and then manually operated to close, otherwise the core cannot be sucked when the loss-of-voltage release is not powered.

(4) The rest shall be adjusted according to Item 6 (2) (3).

8. After the load switch and the operating mechanism are installed, they should be "opened" and "closed" for 10 times respectively, and the following checks and adjustments should be made to the load switch.

(1) During the operation, the rotating part shall be flexible and free from jamming and other phenomena impeding the normal operation of the switch.

(2) The breaking distance from the blade of the load switch to the upper stationary contact should be within 182 ± 3 mm. If it exceeds this range, it can be achieved by adjusting the connecting rod 3 in Figure 5 and Figure 6, the connecting rod 2 in Figure 7 or the gasket in the rubber buffer of the load switch.

(3) When the load switch is at the closing position, the lower edge of the blade should be aligned with the edge on the red line mark of the main static melting head. Otherwise, it should be adjusted. Adjust the blade and insulating pull rod, and check whether the device condition of arc static contact conforms to Figure 3.

(4) During the "opening" and "closing" process of the load switch, there should be no excessive friction between the arcing contact and the nozzle, otherwise, the arcing contact and the blade should be adjusted, and the device of the arcing contact should be checked to see if it conforms to Figure 3.

(5) When the load switch is at the closing position, there should be a gap of 1 ± 0.5 mm between the outer edge of cam 6 on the auxiliary shaft and the release 7, which can be achieved by adjusting screw 9. (See Figure 6)

(6) The different simultaneous contact deviation of the three-phase arc contact of the load switch shall not be greater than 4mm, which can be achieved by adjusting the hexagon eccentricity at the connection of the blade and the insulating pull rod.

(7) After the load switch is adjusted, the speed test shall be carried out to reach the upper opening speed of 4.8 ± 0.5 m/s and the closing speed of 7.4 ± 0.5 m/s, and the closing speed of 3.6 ± 0.4 m/s