JPH0766716B2 - Low-voltage switch with bypass terminal for 3-phase 4-wire - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates generally to manual electrical switches, and more particularly to transformer secondary side switches for low voltage overhead distribution lines.

(Prior art and its problems) The conventional secondary side switch used for the transformer of the low voltage overhead distribution line is for single pole (see Fig. 8), and there is no multi-pole simultaneous switch. Since multiple switches for single pole are installed and operated individually, (1) malfunction of control relay circuit, (2) disturbance of output waveform of rectifier circuit, especially when switching three-phase load.
(3) In the worst case, the electric motor may be burned out. In addition, as structural problems, (a) it is dangerous because the charging part is exposed when the contact is opened, (b) an arc is visible during opening and closing operations, and (c) the open type causes corrosion or (D) The structure of the contact part, which is prone to performance deterioration, is the so-called self-contact type, and the contact pressure depends only on the elasticity of the conductive member (copper) itself, so there are variations during production or at the construction site. (E) Electric wire connection part (terminal) is tightened by screw because of improper handling. (E) Electric wire connection part (terminal) is screwed inadequately. (F) There are drawbacks such as blackouts inevitable when replacing transformers.

(Means for Solving the Problems) In the switch according to the present invention, since the three-phase four-wire structure and the three-phase contactors operate integrally at the same time, the disadvantages of the above items 1 to 3 are eliminated. By storing the switch body assembly in a casing to form a completely sealed type, (a),
Solve the problems of (b) and (c), answer the above item (d) by giving elasticity to the contact with a spring plate and coil spring, and use the tulip terminal as the electric wire connection part and (e) item. Except for the concern of
Solved the item problem.

(Operation) The structure of the switch according to the present invention is such that the movable contact holding elasticity by the spring plate and the coil spring rotates to electrically connect the fixed contact on the power supply side and the fixed contact on the load side. 3 sets of sub-assemblies are linked so that they can be interlocked for 3 phases, and a neutral-phase electrode assembly is also linked and stored in a hermetically sealed housing, and the lock mechanism is released by pressing a push button provided outside the housing. By operating the handle outside the housing, the three sets of movable contacts that rotate integrally are operated to perform the opening / closing operation. When the push button is released after operating the handle, the handle is locked in that position. A spring is attached to the eccentric part for the operation of the handle so that the movable contact does not stop during the opening and closing. Also, use tulip terminals for the connecting wire terminals to eliminate uncertainties such as insufficient tightening, and provide bypass terminals for each phase to connect from another power source when replacing the transformer, resulting in a power failure on the load side. I try not to. Since it is a three-phase, four-wire configuration, if the 200V terminals of the common transformer are connected to U and V, the neutral phase is connected to N, and the 200V of the power transformer is connected to the V and W terminals, then U, V, and W on the load side. Three-phase 200V between terminals, single-phase 20 between U and V terminals
It is easily understood with reference to FIG. 7 that single phase 100V can be obtained between 0V, U and N and between V and N, respectively.

(Embodiment) An embodiment of a low-voltage switch with a bypass terminal for three-phase four-wire according to the present invention will be described with reference to FIGS. 1 to 6.

As shown in FIG. 1, the body assembly 2 of the switch 1 is housed in a box-shaped upper and lower housings 3 and 4 which are electrically insulative and durable and made of, for example, FRP. Has been done. The tulip terminals 5a of the four phases U, V, W, and N arranged on the upper right side of the main assembly 2 in the direction of the arrow A are on the power source side, and the central row is a spare terminal for each, and the long left side The tulip terminals 5b are respective bypass terminals.
In FIG. 1 (B), the cylindrical caps 3a and 3b attached to the upper housing 3 are screwed into the housing for transporting and storing the switch 1, and the connection plug on the power source side is connected to the terminals 5a and 5b. The socket portions 3c and 3d are exposed by being removed at the time of connection, and the wiring is made watertight by a known method such as gland packing using the inner screws of the sockets 3c and 3d. (Handle 16 on the upper surface of the upper housing 3
Two mounting seats near the front and rear ends.
3e, and front and rear plates 6a, 6b (second
(See FIG. 3 and FIG. 3) It serves as a screw seat for fixing the housing 3 to the nut 7 fixed to the upper flange portions 6c and 6d. The lower housing 4 has the same structure as the upper housing 3, and the lower flange portions 6e and 6f of the front and rear plates 6a and 6b.
It is screwed to the nut 7 fixed to the.

The body assembly 2 includes three sets of contact assemblies 25, one set of neutral phase electrode assemblies 35, and plates 6a, 6b in front of and behind these assemblies, as is apparent from FIG. There is. The front plate 6a has a U-shaped cross section as shown in FIGS. 1 and 2, and a nut 7 is fixed to the upper and lower flanges 6c and 6e by, for example, welding. Four
Plays the role of screwing. At the center of the front plate 6a, there is a through hole through which the rotary shaft 15 can freely rotate, and at a position symmetrical to the through hole, the contactor assembly 25 and the neutral phase electrode assembly are provided.
A hole is provided through which the bolt 8 is inserted through the hole 26f so as to fix the 35 adjacently to each other at the ends of the boss 26e (see FIG. 5).
The bolt 8 (see FIG. 3) and the nut 9 allow the assembly 25,
35 is held between the front and rear plates 6a, 6b. Further, a lock plate 10 having a key hole 10a in the front plate 6a and a push button 11 fixed to one end is movably attached to the left and right in the figure, and a coil spring 12 attached between pins 13 and 14.
Is always pulled to the left by, the square portion of the key hole 10a is engaged with the rotary shaft 15 having a square cross section to prevent the rotary shaft 15 from rotating, and the handle 16 is provided in front of the rotary shaft 15. It is fixed. On the other hand, the rear plate 6b also has a U-shaped cross section with reference to FIGS. 1 and 3, and the upper and lower flanges 6d and 6f
A nut 7 is fixedly attached to the front plate 6a, and the upper and lower housings 3 and 4 are screwed in the same manner as in the front plate 6a. The rear plate 6b is provided with a hole through which the above-mentioned bolt 8 is inserted, at a position corresponding to the case of the front plate 6a, and has a circular hole 6g at the center thereof, and a through hole 33b of the movable contactor core 33 (see FIG. 5). ) Through which a plate 17 fixed to bolts 18 for fixing cores 33 adjacent to each other at the end of boss 33a can rotate. Pins fixed to plate 17
The coil spring 21 is attached between the pin 19 and the pin 20 fixed to the rear plate 6b, and is expanded in the closed state. When the circuit is cut off, a quick return effect is provided and the coil spring 21 is prevented from remaining in the incomplete contact position.

Next, referring to FIGS. 4 and 5, the contactor assembly 25 includes a rectangular plate 26a formed of an electrically insulating material, a flange 26b formed around the plate 26a, and a pin 34 engaged in the center thereof. The circular hole 26c and the half-moon shaped slot 26d and the boss 26e are provided at positions symmetrical to the hole 26c, and the boss 26e has a hole 26f through which the bolt 8 (see FIG. 3) passes. The upper and lower surfaces of the flange 26b are made of a conductive material (copper in this example), and fixed contacts 27 and 28 on the power supply side and the load side are attached with a set screw 27a and a square nut 27c, respectively. Is prevented from rotating due to the protrusion 26g of the flange 26b, and the fixed contacts 27, 28 are screwed to the plugs 27b with which the tulip terminals 5a, 5b are engaged. The fixed contacts 27, 28 are made slightly wider than the flange 26b. On the other hand, the movable contactor core 33 molded from an electrically insulating material has a boss 33b having a through hole 33c that engages with the pin 34 at the center of a circular plate-shaped body 33a, and at a peripheral portion symmetrical to the boss 33b. Boss 33d
Are reinforced by arcuate ribs 33f on both sides, and the boss 3
3d has a hole 33e through which the bolt 18 (see FIG. 3) passes. Further, the rib 33f has a notch 33 at a position symmetrical with respect to the boss 33b.
g, and the width is a little wider than the width of the movable contact 29. The boss 33b serves as a guide for the washer 32 and the spring 31. The movable contact 29 has a plate shape made of an electrically conductive material (a copper plate in this example) and has a stepped central portion with a central hole. The spring plate 30 has the same shape as the movable contact 29, and is a movable contact.
It serves to give 29 a springiness. In a state where these parts are assembled as shown in FIG. 4, the protruding portions of the movable contactor 29 in the step form contact with the boss 26h of the core 26, and the spring plate 30, from behind the movable contactor 29, The coil spring 31 pushes, the movable contact 29 and the spring plate 30 engage with the notch 33g of the core 33, and the boss 33d passes through the slot 26d of the core 26 and the boss 33d of the adjacent core 33 and the bolt 18 and the nut. Is solidly connected and guided by the slot 26d to rotate,
A contact set as shown in FIG. 4 in which the centers of the fixed contact core 26, the movable contact 29, the spring plate 30, and the movable contact core 33 are aligned with each other by a pin 34 which is fixed by a set screw 34a. It becomes solid 25.

Referring to FIGS. 1 and 6, the neutral phase electrode assembly 35 includes a plate-shaped mounting core 36 molded from an electrically insulating material,
The U-shaped electrode 37 is attached to the lower flange in the same manner as the fixed contact 27 of the contact assembly 25, and the mounting core 36 is attached.
Has substantially the same structure as the fixed contact core 26 except that there is no slot 26d. The power supply side above the electrode 37 has the same structure as the fixed contact 27, but the lower load side is connected to the tulip terminal 5b, one is connected to the ground wire and the other is connected to the cylindrical terminal
38 is attached.

Referring to FIG. 7, when the 200V terminal of the common transformer T1 is connected to U and V, the neutral phase is connected to N, and the 200V of the power transformer T2 is connected to V and W, the power source side terminals of the switch of the present invention are referred to. , U on the load side,
Three-phase 200V for V and W, single-phase 200V for U and V, U, N and V,
A single phase of 100V is obtained for each N.

Next, the operation method will be described with reference to FIG.
To open and close the switch of the present invention, first push the push button 11
When pushed in the direction of the arrow against 12, the circular portion of the keyhole 10a engages with the rotating shaft 15 and the rotating shaft 15 becomes rotatable,
The handle 16 is rotated clockwise by about 90 ° and is fixed to the rotary shaft 15, and the plate on the opposite side has the same structure as the plate 17 shown in FIG.
Since it is firmly attached to the movable contactor core 33 of the contactor assembly 25 next to 35, all the cores 33 are integrated into one unit.
Rotating 90 degrees clockwise, the movable contact 29 in the horizontal position becomes the vertical position, and the spring plates 30 and 31 press the springs 30 and 31 on both sides of the fixed contacts 27 and 28 while maintaining elasticity. Both contacts 27, 28 are electrically connected. When the push button 11 is released, the lock plate 10 is returned to the position shown in FIG. 2 by the force of the spring 12, and the square portion of the key hole 10a is engaged with the rotary shaft 15 having a square cross section to prevent rotation. . At the time of opening, the spring 21 shown in FIG. 3 performs a quick return action to speed up the opening time of the movable contact 29 to make it difficult for the arc to fly and prevent it from stopping at the intermediate position of opening and closing. In this embodiment, the movable contactor has been described as a rotating type, but a linearly moving type is also conceivable.

(Effect of the invention) Since the switch of the present invention is a completely sealed type, corrosion or performance deterioration due to rainwater can be prevented, and it is safe because the charging part is not exposed. There is no uncertainty or individual unevenness, the contact structure uses coil springs and leaf springs to provide stability and durability, and there is a push-button locking mechanism, so there is a concern that the handle may accidentally operate when it hits an object. There is no such thing, because it is a three-phase batch open system, it does not enter the next phase state, and since a bypass terminal is provided,
It has the advantage that transformers can be replaced without interruption.

[Brief description of drawings]

FIG. 1 is a perspective view of a low-voltage switch with bypass for three-phase four-wire according to the present invention, in which the upper housing is removed, FIG. 2 is a view taken along arrow A of FIG. 1, and FIG. 3 is taken along arrow B of FIG. Fig. 4, Fig. 4 is a perspective view of a contactor assembly pair, Fig. 5 is an exploded perspective view of Fig. 4, Fig. 6 is a partial view of a neutral phase electrode assembly, and Fig. 7 is an electric circuit diagram of the switch. FIG. 8 is a side view of a conventional single pole switch. (Explanation of signs) 1 ... Switch, 2 ... Main body assembly, 3 ... Upper housing 3a, 3b ... Cap, 3c, 3d ... Socket 3e ... Mounting seat, 4 ... Lower housing 5a, 5b ...... Tulip terminal, 6a ...... Front plate 6b …… Rear plate, 6c, 6e, 6f …… Flange 6g …… Round hole, 7 …… Nut, 8 …… Bolt, 9 …… Nut 10 …… Lock plate, 10a …… Key hole, 11 …… Push button 12 …… Coil spring, 13,14 …… Pin, 15 …… Rotating shaft 16 …… Handle, 17 …… Plate, 18 …… Bolt 19,20 …… Pin, 21 …… Coil spring 25 …… Contact assembly, 26 …… Fixed contact core 26a …… Plate, 26b …… Flange, 26c …… Hole 26d …… Groove hole, 26e …… Boss, 26f …… Hole 26g …… Raised, 26h …… Boss, 27,28 …… Fixed contact 27a …… Set screw, 27b …… Plug, 27c …… Square nut 29 …… Moveable contact, 30 …… Spring plate 31 … Coil spring, 32… Washer, 33… Movable contact core 33a… Plate, 33b… Boss, 33c… Hole 33d… Boss, 33e… Hole, 33f… Rib 33g… Off Notch, 34 ... Pin, 34a ... Set screw 35 ... Neutral phase electrode assembly, 36 ... Mounting core, 37 ... Electrode 38 ... Terminal

Front page continuation (72) Inventor Yoshitomo Wakai 3-5-6 East Monzen, Kawasaki-ku, Kawasaki-shi, Kanagawa Tomita Denki Seisakusho Co., Ltd. (72) Mitsukata Mitsuo 5-11-7 Nishi-nippori, Arakawa-ku, Tokyo Kinho Denki Co., Ltd. (56) Bibliography Sho 61-23245 (JP, U)

Claims (3)

[Claims] 1. A low-voltage switch with a bypass terminal for a three-phase four-wire, comprising a fixed contact on the power supply side and a load side, which has at least one ordinary terminal and a bypass terminal, and a three-phase movable contact. And a neutral phase electrode assembly, and a sealed housing that houses the contact assembly and the neutral phase electrode assembly, wherein the movable contact is in the axial direction. Are juxtaposed and connected together
For its rotation, a spring is attached to the eccentric part, and a rotary shaft with a square cross section is adjacent to a square hole and a circular hole that engage with the rotary shaft. A lock mechanism composed of a plate having, the lock of the rectangular rotary shaft is released by moving the plate in the longitudinal direction, and the movable contact can be operated only while the lock mechanism is released. It is rotated and is not stopped at the intermediate position of the opening and closing, and the handle is operated from the outside of the housing to simultaneously rotate to open and close the electric path, and temporary power is supplied from the bypass terminal to cause a power failure to the load side. A low-voltage switch with a bypass terminal for a three-phase four-wire, which is characterized in that it is possible to carry out construction work such as transformer replacement without occurring. 2. A low-voltage switch with a bypass terminal for a three-phase four-wire system according to claim 1, wherein the movable contact is held elastic by a spring plate and a coil spring. 3. A low-voltage switch with a bypass terminal for a three-phase four-wire according to claim 1, wherein a tulip terminal is used to connect the distribution line terminals.