JPS6115562Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a simple circuit breaker that is used in submersible pumps, etc., and automatically cuts off the electrical circuit by detecting overload, short circuit, or leakage. The purpose of the present invention is to provide a circuit breaker that has excellent insulation properties and is easy to assemble.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings, which are examples of the present invention.

The figure shows an earth leakage breaker, which is roughly composed of a base 1, a relay body 24, a circuit section 40, a zero-phase current transformer 52, a case 60, and a terminal cover 81.

The base 1 is integrally molded of synthetic resin, plugs 2, 2 serving as power terminals are insert molded therein, and a stepped portion 3 is provided at the outer peripheral end over the entire circumference. In addition, there are five through holes 4 on the top surface,
5, 6, 7, 8, square holes 9, 9, recesses 10, 11, a barrier 12, and a cylindrical circuit housing portion 13 are provided. Load terminals 14 and 17 are each punched out from a single conductive metal plate and bent as appropriate, and are fitted into the recesses 10 and 11 and positioned. Fixed contacts 15 and 18 are fixed to one end of the load terminals 14 and 17, and a screw hole 1 is fixed to the other end.
6 and 19 are screwed into the screw holes 16 and 19, and terminal screws 20 and 21 are screwed into the screw holes 16 and 19, respectively.

The relay body 24 includes a yoke 25, a spool 29 around which a coil 28 is wound, an iron core 30 (see FIG. 3), a movable iron piece 31, and an insulating stand 32 on the upper surface of the movable iron piece 31.
Two movable contact pieces 33, 35 fixed via
The protrusion 26 provided at the lower end of the yoke 25 is fitted into the square hole 9 of the base 1 for positioning, and a fixing screw (not shown) is inserted into the through hole 4 from the bottom surface of the base 1. The relay main body 24 is fixed on the base 1 by inserting the yoke 25 and screwing the yoke 25 onto the lower end portion 27 (see FIG. 3). When the relay body 24 is fixed, the movable contacts 34, 36 provided at the tips of the movable contact pieces 33, 35
is fixed contact 15, 1 due to the urging force of return spring 37.
8.

The circuit section 40 consists of a printed circuit board 41 and a control circuit 42 configured by connecting appropriate electronic components to the printed circuit board 41, and is housed in the circuit housing section 13 of the base 1 and insulated from the relay body 24 and the contacts. be done. Two pairs of movable pieces 43, 45 and fixed pieces 44, 46 connected to the control circuit 42 are provided at the upper end of the printed circuit board 41, and a reset button 47 and a test button are provided on the upper surface of the movable pieces 43, 45, respectively. 48 are brought into contact with each other. Furthermore, an earth leakage indicator lamp 49 made of a light emitting diode is attached to the center of the upper end of the printed circuit board 41.

The zero-phase current transformer 52 has its entire outer peripheral surface covered with synthetic resin, and has a through hole 53 in the center, and a main circuit conductor 54 is connected to the through hole 53 at one end to the plugs 2, 2. , 55 is inserted and wound several times,
The zero-phase current transformer 52 is mounted in a floating state from the upper surface of the base 1 due to the rigidity of the main circuit conductors 54 and 55. The other ends of the main circuit conductors 54 and 55 are connected to the movable contact pieces 33 and 35 of the relay body 24. Terminals 56 of the secondary winding protrude from the upper surface of the zero-phase current transformer 52, and these terminals are connected to the control circuit 42 by lead wires (not shown).

The case 60 is integrally molded from synthetic resin, and has a recess 62 on the top surface for mounting a nameplate 61 (see Figure 3), and this recess 62 has three holes 63, 64, and 65. It is provided. Above hole 6
A reset button 47 and a test button 48 protrude from holes 3 and 64, respectively, and another hole 65 corresponds to an earth leakage indicator lamp 49. and,
Large diameter recesses 6 are provided around the holes 63, 64, and 65.
6, 67, and 68 are provided, and by fitting caps 69, 70 and a transparent plate 71 made of rubber into these recesses, and pressing the name plate 61 from above, the upper surface of the case 60 is sealed. becomes. A presser piece 72 is integrally provided at one end of the case 60, and the outline of the case 60 including the presser piece 72 has the same shape as the base 1.
The case 60 and the base 1 are integrated by pressing them onto the top surface of the base 1 through the screws 9 and screwing fixing screws (not shown) into the case 60 from the bottom surface of the base 1 through the through holes 5 and 6. be converted into The lower surface of the holding piece 72 presses the load terminals 14 and 17 when the case 60 and the base 1 are integrated, thereby preventing the load terminals from wobbling. Two exposure holes 73 and 74 are provided in the holding piece 72, and the load terminals 14 and 1 are connected through the holes 73 and 74.
7 and terminal screws 20, 21 are exposed.

The terminal cover 81 is box-shaped with an open bottom and is integrally molded from synthetic resin. A conduit 82 made of a rubber material is fitted into the terminal cover 81, and a cord 83 connected to a load such as a submersible pump passes through the conduit 82 and connects the load terminals 14, 17 exposed from the holding piece 72.
connected to. Then, the terminal cover 81 is crimped onto the holding piece 72 with the packing 80 in between, and a fixing screw (not shown) is inserted from the bottom surface of the base 1 through the through holes 7 and 8 of the base 1 and through the holding piece 72. By screwing the terminal cover 81 through the holes 75 and 76, the terminal cover 81 is fixed onto the presser piece 72.

In the assembled state as described above, the earth leakage breaker inner case 60, base 1 and packing 5
It is sealed with 9 and has a waterproof structure, and
The terminal portion is sealed by a terminal cover 81, a holding piece portion 72, a packing 80, and a conduit 82. Therefore, even if the earth leakage breaker is installed near the submersible pump, there is no possibility that water droplets will enter the earth leakage breaker.

Here, the operation of the earth leakage breaker will be explained.

First, the plug 2 is inserted into an outlet, and one end of the cord 83 is connected to a load such as a submersible pump. In this state, the movable contact 3 of the relay body 24
4 and 36 are in contact with fixed contacts 15 and 18,
The load circuit is in the on state.

Next, when a leakage current occurs in the load, the zero-phase current transformer 5
2, the coil 28 is
is excited, and the movable iron piece 31 is attracted to the iron core 30 and rotates in the clockwise direction in Fig. 3. As a result, the movable contacts 34, 36 separate from the fixed contacts 15, 18, the main circuit is interrupted, and the connection to the load is stopped. At the same time, the leakage current indicator lamp 49 lights up to indicate the occurrence of a leakage current. When interrupting the above-mentioned circuit breaker, if a large current is interrupted, an arc is generated, which may cause an arc short circuit between the contacts of each pole. However, since the barrier 12 is integrally provided on the base 1 and separates the contacts, insulation is provided and there is no risk of an arc short circuit.

Even after the main circuit is cut off, the coil 28 is kept in an excited state by the action of the control circuit 42, and the movable iron piece 31 continues to be attracted to the iron core 30. If you want to reset the load after completing the repair of the earth leakage part, press the cap 69 of the reset button 47 protruding from the front of the case 60, bend the movable piece 43 attached to the printed circuit board 41, and release the fixed piece. 44. As a result, the holding of the control circuit 42 is released, the coil 28 is demagnetized, and
The movable iron piece 31 rotates counterclockwise in FIG. 3 due to the biasing force of the return spring 37, and the movable contacts 34, 36
The fixed contacts 15 and 18 are closed again, and the load circuit is turned on. And the earth leakage indicator lamp 4
9 is also turned off.

To test the operation of this earth leakage breaker, press the cap 70 of the test button 48,
The coil 28 is excited by bringing the movable piece 45 attached to the printed circuit board 41 into contact with the fixed piece 46 . As a result, the movable contacts 34, 36 and the fixed contacts 15, 1
8 and at the same time, the earth leakage indicator lamp 49 lights up, so it can be confirmed that the operation has been performed.

As is clear from the above explanation, according to the present invention, the terminal block and case of the relay are omitted, and the yoke of the relay body is directly attached to the base, so the space can be reduced by that much, and the yoke can be mounted directly on the base. By mounting the relay body, zero-phase current transformer, and control circuit in close proximity, the relay body can be made smaller.
Moreover, since the control circuit is mounted on the printed circuit board, and the load terminals are provided with fixed contacts that come into contact with and separate from the movable contact piece and terminal screws for external connection, wiring work and internal structure can be simplified. Furthermore, since the printed circuit board on which the control circuit is mounted is housed in the cylindrical circuit storage part protruding from the base, sufficient insulation from other conductive parts in the vicinity is ensured.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a circuit breaker according to the present invention, FIG. 2 is a plan view with the case and terminal cover removed, and FIG. 3 is a sectional view taken along the line -- in FIG. 2. 1...Base, 2...Plug (power terminal), 1
0,11...Recess, 12...Barrier, 13...Circuit storage part, 14,17...Load terminal, 15,18
... Fixed contact, 24 ... Relay body, 25 ... Yoke, 28 ... Coil, 30 ... Iron core, 31 ... Movable iron piece, 33, 35 ... Movable contact piece, 34, 36
. . . Movable contact, 40 . Zero-phase current transformer, 5
4, 55...Main circuit conductor, 60...Case, 7
2... Presser piece part, 81... Terminal cover, 82...
Conduit.

Claims (1)

[Scope of utility model registration request] A pair of plug-shaped power terminals are provided protruding from the bottom surface of the base, a zero-phase current transformer and a relay body are arranged close to each other on the top surface of the base, and the pair of movable contact pieces of the relay body are located at one end of the base. The yoke of the relay body is directly fixed on the base so that the yoke of the relay body is located at established,
A printed circuit board mounted with a control circuit that operates and self-maintains the relay main body according to the output of the zero-phase current transformer is vertically stored in this circuit housing part, and the power terminal and movable contact piece are connected to the zero-phase current transformer. The secondary winding of the zero-phase current transformer is connected to the control circuit through a current transformer, and a pair of load terminals are fitted and positioned in a recess on the upper surface of one end of the base. A fixed contact is provided at one end to face the movable contact piece,
A circuit breaker characterized in that a terminal screw is provided at the other end of the load terminal, and the top surface of the load terminal is pressed by a case that covers the top surface of the base.