JP2010010322A - Electric apparatus with current transformer built therein, and short-circuiting plug for protecting current transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric apparatus with a current transformer built therein, equipped with a short-circuiting plug short-circuiting the secondary side of the current transformer to protect it when not used. <P>SOLUTION: A receptacle 4 is attached to a case 3 housing the electric apparatus body together with the current transformer and the secondary side of the current transformer is connected to contacts 402a to 402f of the receptacle 4. The electric apparatus is equipped with the short-circuiting plug 6 to be inserted into the receptacle 4 when a plug for taking an output out of the current transformer is detached from the receptacle 4. The short-circuiting plug 6 includes a short-circuiting plug body 603 having short-circuiting contacts 601a to 601f respectively connected to the contacts 402a to 402f of the receptacle 4 and a short-circuiting plate 602 connecting together these short-circuiting contacts, an insulating plate 604 covering an end face of the short-circuiting plate 602 and a knob 605. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric device with a built-in current transformer in which a current transformer is built in a case housing an electric device main body, and a short-circuit plug for current transformer protection used for protecting the current transformer in the electric device. It is about.

  When it is necessary to measure the alternating current flowing through the circuit configured in the case in the case where the electric device main body is housed in the case, a current transformer is provided in the case containing the electric device main body. The output of the current transformer is taken out through an outlet and an insertion plug inserted into the outlet.

  For example, in a section switch installed in a power distribution system or a switch provided in an outer box of a road-mounted transformer device, a current transformer that detects at least two-phase line current in a case housing the switch body The secondary side of each current transformer is connected to the contact of the outlet attached to the case, and the insertion plug attached to one end of the measurement cable connected to the external device such as the display is connected to the outlet. By doing so, the output of each current transformer is taken out and supplied to devices such as a display.

  A commercially available (standard product) metal outlet is usually used as the outlet attached to the case containing the electric device main body. The metal outlet includes a main body having a structure in which a plurality of outlet-side contacts are accommodated in a housing having an opening for receiving an insertion plug at one end, with respective axes oriented in the axial direction of the housing. And a cap that closes the opening of the housing of the outlet body when the plug is removed from the outlet body.

  As is well known, a current transformer is provided with a primary conductor through which a current to be measured flows, a core through which a magnetic flux generated by the current flowing through the primary conductor flows, and a secondary coil wound around the core. Thus, there are a through type using a through conductor arranged as a primary conductor penetrating the core and a winding type using a coil wound around the core as a primary conductor. There are two types of through-type current transformers, one in which a dedicated through conductor is provided by penetrating a core, and the other in which a conductor through which a current to be measured flows is used as a through conductor. In the case of measuring a large current in a power circuit, in most cases, a through-type current transformer is used. However, any type of current transformer built in an electric device targeted by the present invention is used. good. In any type of current transformer, when measuring a large current, if the secondary side is opened while the primary conductor is energized, an overvoltage is generated in the secondary coil, and the current transformer Opening the secondary side of the current transformer must be avoided because it may burn out or cause an electric shock. Therefore, when measuring an alternating current with a current transformer, a burden resistor is connected to the secondary side, and a current flowing through the primary side is detected from a voltage at both ends of the burden resistor. In general, by providing a measurement circuit with a burden resistance on the external device side such as a display and connecting the measurement circuit to the current transformer through a measurement cable, the secondary side of the current transformer is opened. Is prevented.

  As described above, when the current transformer provided in the electrical device is connected to the measurement circuit through the measurement cable, the current transformer is not normally opened, but the electrical device is not connected to the external device. If it is assumed that the electric device is used alone, for example, if the electric device is assumed to be installed and operated prior to the installation of the external device, the secondary of the current transformer It is necessary to provide some protective means in case the side is opened. Even if the current transformer is connected to the measurement circuit through the measurement cable, if it is assumed that the burden resistance is disconnected from the current transformer due to a failure of the measurement circuit, the current transformer It is necessary to provide a protective means in case the next side is opened.

  Therefore, as shown in Patent Document 1, the diode bridge full-wave rectifier circuit on the secondary side of the current transformer, the transistor connected between the output terminals of the rectifier circuit, and the output voltage of the rectifier circuit are Connect a protection circuit with a zener diode that conducts when the set value is exceeded and flow the base current to the transistor, and when the overvoltage occurs on the secondary side of the current transformer, the zener diode is turned on and the transistor A protection device has been proposed in which the secondary side of the current transformer is short-circuited by turning on the power supply.

Moreover, as shown in Patent Document 2, a series circuit of a current detector and a lightning arrester at both ends of the secondary coil of the current transformer, and a short-circuit contact that closes when the current detector detects a current, Are connected in parallel, and when an overvoltage occurs on the secondary side of the current transformer, the surge arrester is operated and the current is passed through the current detector to close the short-circuit contact. Proposals have also been made for protection devices that are short-circuited on the sides.
JP-A-10-274663 JP 2007-35808 A

  In the case of the protection device disclosed in Patent Document 1, there is a problem that the reliability is uneasy because the protection operation is not performed if one of the many diodes is damaged.

  Moreover, in the case of the protection device disclosed in Patent Document 2, it is necessary to provide a lightning arrester, a current detector, and a short-circuit contact for each current transformer disposed in the case of the electrical equipment. Not only is the structure in the case of the equipment complicated, but the cost of the electrical equipment is unavoidably high.

  When an electric device equipped with a current transformer is used alone, connect the measurement cable to the outlet attached to the case of the electric device via a plug, and leave the measurement cable outlet. A short-circuit piece that short-circuits the secondary side of the current transformer is connected to the terminal portion on the other side, but in this case, a measurement cable is also used when using an electric device alone. There was a problem that it had to be connected and was troublesome.

  In addition, when a current transformer is not used, a shorting plug that short-circuits between the contacts of the metal outlet is provided in a metal outlet attached to the case of the electrical device in order to extract the output of the current transformer to the outside. It is also possible to accommodate them. However, since a commercially available metal outlet does not have a sufficient space in the housing, it is necessary to devise a compact configuration of the shorting plug in order to accommodate the shorting plug therein.

  An object of the present invention is to provide a current transformer comprising a case containing an electric device main body, and a current transformer that measures an alternating current that is housed in the case together with the electric device main body and flows through a circuit configured in the case. An object of the present invention is to enable protection of a current transformer without impairing reliability and without increasing costs in a built-in electric device.

  Another object of the present invention is to provide an electrical device with a built-in current transformer in order to protect the current transformer without impairing reliability and without increasing the cost. An object of the present invention is to provide a short-circuit plug for protecting a current transformer that can be used by being connected to an outlet provided in the case.

  The present invention includes a case in which an electric device main body is accommodated, a current transformer that is accommodated in the case together with the electric device main body, and is provided to measure an alternating current flowing through a circuit configured in the case. A contact connected to one end of the secondary coil of the flow device, and an outlet attached to the case having a plurality of outlet-side contacts including a contact connected to the other end of the secondary coil. In addition, it is intended for electric devices with built-in current transformers, in which the output of each current transformer is taken out through an outlet and an insertion plug connected to the outlet.

  The outlet used in the electrical apparatus targeted by the present invention includes a plurality of outlets in a housing having an opening for receiving an insertion plug having a plurality of plug-side contacts respectively connected to the plurality of outlet-side contacts. The outlet body has a structure that accommodates the outlet side contactors with their respective axes oriented in the axial direction of the housing, and the opening of the outlet body housing when the plug is removed from the outlet body. With a closing cap.

  The electric device with a built-in current transformer according to the present invention is provided with a short-circuit plug that is inserted into the housing of the outlet body with the insertion plug removed, and short-circuits the plurality of outlet-side contacts. The short-circuit plug includes a short-circuit plug body having a plurality of short-circuit contacts that respectively contact a plurality of outlet-side contacts in the outlet housing, and a short-circuit plug body disposed toward the opening side of the outlet body housing. An insulating portion that covers the end surface, and an insulating knob that is provided so as to protrude from the insulating portion toward the opening of the housing and is fixed to the short-circuit plug body, and the opening is closed by a cap. It is configured to have a size that fits within the housing of the outlet body in a closed state.

  When a current transformer is not used if a short-circuit plug that short-circuits between multiple contacts of the outlet is provided by inserting it into the outlet body housing with the plug inserted in the state as described above. In addition, since the secondary side of the current transformer provided in the electric device can be held in a short-circuited state, the electric device incorporating the current transformer can be used alone stably for a long period of time.

  In addition, the above short-circuit plug has only a short-circuit plug body having a short-circuit contact, an insulating portion covering the end face of the short-circuit plug body, and a knob, and has a simple structure without a plug housing. It is easy to make it compact so as to be accommodated in the outlet.

  When the contact provided on the plug to be connected to the outlet is male and the outlet-side contact provided on the outlet body is a female contact, one end of the short-circuit plug is within the outlet housing. A plurality of male short-circuit contacts that are brought into contact with a plurality of outlet-side contacts, and the plurality of short-circuit contacts are provided to be electrically connected to each other on the other end side of the plurality of short-circuit contacts. A short-circuit plug body having a short-circuit plate arranged toward the opening of the outlet body housing, and an end face of the short-circuit plate facing the opening side of the outlet body housing. And a shorting plug body provided so as to protrude from the insulating plate to the opening side of the housing It is preferable to adopt a configuration in which a fixed insulating knob against.

  When configured as described above, by sufficiently reducing the thickness of the short-circuit plate and the insulating plate covering the short-circuit plate and keeping the protrusion length of the knob to the minimum necessary, the axial dimension of the short-circuit plug is reduced, Since the shorting plug can be made compact, it can be easily applied even when a standard metal outlet is used as an outlet attached to the case of the electric device.

  In a preferred aspect of the present invention, the knob of the short-circuit plug is formed in a cylindrical shape, and the knob mounting hole provided through the short-circuit plate and the knob provided on the insulating plate so as to be aligned with the knob mounting hole It is attached to the short circuit plate through the through hole. An engaging portion that engages with each other and prevents the knob from coming out of the knob mounting hole is provided on the outer peripheral portion of the knob disposed in the knob mounting hole and the inner peripheral portion of the knob mounting hole. In addition, the knob contacts the inner surface of the cap when the opening of the housing of the outlet body of the plug is closed by the cap in a state where the plurality of short-circuit contacts are in contact with the plurality of outlet-side contacts, respectively. A plug is provided to prevent the plug from coming off from the outlet side contact.

  If comprised as mentioned above, the structure of a short-circuit plug can be simplified. In addition, a short-circuit plug can be assembled by simply stacking the short-circuit plate and insulation plate and fitting the knob into the knob mounting hole provided in the short-circuit plate and the knob through-hole provided in the insulation plate. The assembly of the plug can be simplified.

  In addition, when configured as described above, when the short-circuit contact is brought into contact with the outlet-side contact, and the opening of the outlet body housing is closed by the cap, the knob contacts the inner surface of the cap and the short-circuit plug is plugged into the outlet. In order to prevent displacement in the direction away from the side contact, the state where the secondary side of the current transformer is short-circuited can be stably maintained for a long period of time.

  In a preferred aspect of the present invention, the ring is loosely fitted into a hole provided through the knob in a direction orthogonal to the axial direction of the short-circuit contact, and the ring has an inner diameter of the knob through-hole provided in the insulating plate. Has a larger outer diameter.

  If a ring is attached to the knob as described above, the shorting plug can be pulled out by holding the ring even if the knob is formed in a small size. Therefore, it is possible to easily obtain a short-circuit plug that can be accommodated in a standard outlet.

  Further, as described above, if the outer diameter of the ring is made larger than the inner diameter of the knob through-hole provided in the insulating plate, the insulating plate can be prevented from coming off by the ring. The trouble of fixing to the short-circuit plate can be saved.

  In another preferred aspect of the present invention, the insulating plate and the knob are made of an insulating material having elasticity, and the annular knob is formed integrally with the insulating plate. In this case, the insulating plate has a protruding portion protruding toward the short-circuit plate, and is attached to the short-circuit plate in a state where the protruding portion is press-fitted into an insulating plate mounting hole provided in the short-circuit plate. An engaging portion that engages with each other and prevents the protruding portion from coming out of the insulating plate mounting hole at the outer peripheral portion of the portion press-fitted into the insulating plate mounting hole of the protruding portion and the inner peripheral portion of the insulating plate mounting hole. Is provided. In addition, the knob is provided between the inner surface of the cap and the insulating plate when the opening of the housing of the outlet body is closed by the cap with the plurality of short-circuit contacts in contact with the plurality of outlet-side contacts. It arrange | positions in the compressed state and is provided so that a short-circuit plug may prevent removing from an outlet side contactor.

  As described above, if the knob formed in an annular shape is integrated with the insulating plate, the number of parts of the shorting plug can be reduced and the configuration of the shorting plug can be simplified. In addition, as described above, when the opening of the housing of the outlet body is closed by the cap, the knob is arranged in a compressed state between the inner surface of the cap and the insulating plate. Because of the repulsive force, the shorting plug is urged to the outlet side contactor side, and the shorting plug can be prevented from coming off from the outlet side contactor, so that the secondary side of the current transformer is short-circuited for a long time. Can be held stably over the entire range.

  According to the present invention, there is also provided a case in which an electric device main body is accommodated, and a current transformer that is accommodated in the case together with the electric device main body and that measures an alternating current flowing through a circuit configured in the case. And an outlet attached to the case having a plurality of outlet side contacts including a contact connected to one end of the secondary coil of the current transformer and a contact connected to the other end of the secondary coil; Protects the current transformer when the plug is removed from the outlet of the electrical device with built-in current transformer, where the output of each current transformer is taken out through the outlet and the plug connected to the outlet. Therefore, a short-circuit plug for protecting a current transformer is provided which is inserted into an outlet instead of the plug-in plug.

  The outlet used in the present invention also includes a plurality of outlet side contacts in a housing provided with an opening at one end for receiving an insertion plug having a plurality of plug side contacts respectively connected to the plurality of outlet side contacts. An outlet body having a structure in which the axis of the housing is accommodated in the axial direction of the housing, and a cap that closes the opening of the outlet body housing when the plug is removed from the outlet body. Yes.

  A short-circuit plug according to the present invention includes a short-circuit plug body having a plurality of short-circuit contacts that respectively contact a plurality of outlet-side contacts in the outlet housing, and a short circuit disposed toward the opening side of the outlet body housing. An insulating part that covers the end face of the plug body, and an insulating knob that is provided so as to protrude from the insulating part toward the opening side of the housing and is fixed to the short-circuiting plug body. It is configured to have a size that fits within the housing of the outlet body in the closed state.

  When the outlet-side contact is a female contact, the short-circuit plug according to the present invention includes a plurality of short-circuit contacts whose one end is brought into contact with each of the plurality of outlet-side contacts in the outlet housing. A short-circuit plug body having a short-circuit plate provided to electrically connect the plurality of short-circuit contacts to each other on the other end side of the short-circuit contact and disposed toward the opening of the housing of the outlet body; An insulating plate disposed on the short-circuit plate so as to cover an end face of the outlet body of the outlet body of the short-circuit plate, and a short-circuit plug body provided so as to protrude from the insulating plate toward the opening of the housing And an insulating knob fixed to the outlet, and the outlet is closed with a cap. Configured to have a size that fits within the body of the housing.

  In a preferred embodiment of the present invention, the knob of the short-circuit plug is formed in a columnar shape, and the short-circuit plate is formed through the knob attachment hole provided through the short-circuit plate and the knob through-hole provided in the insulating plate. It is attached. An engaging portion that engages with each other and prevents the knob from coming out of the knob mounting hole is provided at the outer peripheral portion of the portion arranged in the knob mounting hole of the knob and the inner peripheral portion of the knob mounting hole. . The knob is provided so as to abut against the cap when the opening of the housing of the outlet body is closed by the cap and prevent the short-circuit plug from being detached from the outlet-side contact. Further, a ring having an outer diameter larger than the inner diameter of the knob through-hole provided in the insulating plate is loosely fitted into a hole provided through the knob in a direction orthogonal to the axial direction of the short-circuit contact. .

  In a preferred aspect of the present invention, the insulating plate and the knob are made of an insulating material having elasticity, and the knob is integrally formed on the insulating plate. In this case, the insulating plate has a protruding portion protruding toward the short-circuit plate, and is attached to the short-circuit plate in a state where the protruding portion is press-fitted into an insulating plate mounting hole provided in the short-circuit plate. Further, the outer peripheral portion of the portion press-fitted into the insulating plate mounting hole of the protruding portion and the inner peripheral portion of the insulating plate mounting hole are engaged with each other to prevent the protruding portion from coming out of the insulating plate mounting hole. An engaging portion is provided. Also in this case, the knob is arranged in a compressed state between the cap and the insulating plate when the opening of the housing of the outlet body is closed by the cap, so that the short-circuit plug is detached from the outlet-side contactor. Is provided to prevent.

  According to the present invention, when the current transformer is not used by providing the short-circuit plug that is inserted into the housing of the outlet main body in a state in which the plug is removed, and short-circuits the plurality of contacts of the outlet. Since the secondary side of the current transformer provided in the electric device can be kept short-circuited, the electric device incorporating the current transformer can be used stably for a long period of time.

  In the present invention, the short-circuit plug includes a plurality of short-circuit contacts whose one end is brought into contact with the plurality of outlet-side contacts in the outlet housing, and the plurality of short-circuit contacts on the other end of the plurality of short-circuit contacts. A short-circuit plug body having a short-circuit plate electrically connected to each other, an insulation plate disposed on the short-circuit plate so as to cover an end surface of the short-circuit plate outlet housing facing the housing, and this insulation When the shorting plug is constituted by an insulating knob provided so as to protrude from the plate to the opening side of the housing and fixed to the shorting plug body, the shorting plate and the insulating plate covering the shorting plate The axial direction of the short-circuit plug is reduced by reducing the thickness sufficiently and keeping the protrusion length of the knob to the minimum necessary. By reducing the size, it is possible to configure the short plug compact, it can be easily applied to a case where the metal outlet standard product is used as a concentrate to be attached to the electrical equipment case.

  In the present invention, the knob of the shorting plug is formed in a cylindrical shape, and the knob is attached to the shorting plate in a state of passing through the knob mounting hole provided through the shorting plate and the knob through hole provided in the insulating plate. In such a configuration, the structure of the short-circuit plug can be simplified. In addition, a short-circuit plug can be assembled by simply stacking the short-circuit plate and insulation plate and fitting the knob into the knob mounting hole provided in the short-circuit plate and the knob through-hole provided in the insulation plate. The assembly of the plug can be simplified.

  In addition, the knob is configured to contact the inner surface of the cap when the opening of the housing of the outlet body of the plug is closed by the cap with the plurality of short-circuit contacts being in contact with the plurality of outlet side contacts, respectively. In some cases, the knob can prevent the short-circuit plug from being displaced in a direction away from the outlet-side contact, so that the state where the secondary side of the current transformer is short-circuited is stably maintained for a long period of time. be able to.

  In the present invention, a ring having an outer diameter larger than the inner diameter of the knob through-hole provided in the insulating plate is loosely fitted into the hole provided through the knob in a direction perpendicular to the axial direction of the short-circuit contact. In this case, even if the knob is formed in a small size, the shorting plug can be pulled out by holding the ring, so the protruding length of the knob can be shortened to reduce the size of the shorting plug. A short-circuit plug to be placed inside the outlet can be easily obtained.

  Also, if the outer diameter of the ring fitted in the hole provided in the knob is made larger than the inner diameter of the knob through-hole provided in the insulating plate, the insulating plate can be prevented from coming off by the ring. Thus, the assembly of the shorting plug can be facilitated by eliminating the trouble of fixing the pin to the shorting plate by bonding or the like.

  In the present invention, when the annularly formed knob is integrated with the insulating plate, the number of parts of the shorting plug can be reduced and the configuration of the shorting plug can be simplified. Further, the knob and the insulating plate are formed of an elastic insulating material, and the knob is disposed between the inner surface of the cap and the insulating plate when the opening of the housing of the outlet body is closed by the cap. In this configuration, the repulsive force of the knob can urge the shorting plug toward the outlet side contactor side to prevent the shorting plug from being detached from the outlet side contactor side. The state where the secondary side is short-circuited can be stably maintained for a long period of time.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 to FIG. 7 show an example of a preferred embodiment of the present invention. FIG. 1 is a circuit diagram showing the electrical configuration of the electric equipment. FIG. 2 is a short circuit to the outlet of the electric equipment according to this embodiment. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2, FIG. 4 is an outlet used in the present embodiment, a short-circuit plug inserted into the outlet, and a waterproof cap attached to the outlet. FIG. 5 is a front view of the short-circuit plug as seen from the direction of the VV line of FIG.

  The electrical equipment according to the embodiment shown in FIGS. 1 to 7 is a section switch installed in a power pole and inserted in series in a high-voltage distribution line in a distribution system. FIG. 1 shows an electrical configuration of a section switch according to the present embodiment. In this section switch, a switch (electric device main body) having U, V, W three-phase switches 1u to 1w. 1 and the conductors 2u to 2w connected in series to the three-phase switching parts 1u to 1w of the switch 1, respectively, and the conductors 2u and 2w are provided as primary conductors and flow through the conductors 2u and 2w. Feed-through current transformers CTu and CTw for measuring the phase currents of the phase and the W-phase, respectively, and zero-phase voltage detection capacitors Cu that are star-connected and whose non-neutral point terminals are connected to the conductors 2u to 2w, respectively. Thru Cw, a transformer CPT connected to the primary coil L1p between the neutral point of the capacitors Cu thru Cw and ground, a capacitor C1 connected across the primary coil of the instrument transformer, A case 3 includes a zero-phase current transformer ZCT having a structure in which a secondary coil is wound around a core that collectively surrounds 2u to 2w and that measures a zero-phase current flowing through the conductors 2u to 2w. Yes. A metal outlet 4 is attached to the side wall of the case 3 so that an insertion plug (not shown) can be inserted from the outside.

  As shown in FIGS. 2 and 3, the metal outlet 4 has a space 401a having a substantially circular cross section for inserting a plug (not shown) on the inside, and a flange 401b in the middle. A cylindrical housing 401 having Female outlet-side contacts 402a to 402f are disposed in a void 401a inside the housing 401 and are supported with respect to the housing 401 via an insulating support 403. The housing 401 and the outlet-side contacts An outlet body is constituted by 402a to 402f and the insulating support 403 that supports the outlet side contacts 402a to 402f with respect to the housing. A screw portion 404 is provided on the outer periphery of the opening end on one end side in the axial direction of the housing 401, and a screw portion 405 provided on the inner periphery of the waterproof cap 406 (see FIG. 4) is screwed into the screw portion 404. The outlet body and the cap 406 constitute a metal outlet 4.

  In this specification, in order to distinguish the contact provided on the outlet from the contact provided on the plug, the contact provided on the outlet is referred to as an outlet-side contact, and the contact provided on the plug is referred to as a plug-side contact. However, in the following description, when the configuration of the outlet is described, the outlet side contactor is simply referred to as a contactor unless particularly required.

  In the illustrated example, the insulating support 403 is formed to have a cylindrical shape, and a flange portion 403a provided at one end in the axial direction is the inner circumference of the other end in the axial direction of the metal housing 401. The contacts 402a to 402g are held in a hole fixed to the portion and penetrating the insulating support 403 in the axial direction.

  Of the contacts 402a to 402g, the six contacts 402a to 402f have their respective axes oriented in a direction parallel to the central axis of the housing 401, along a circle that concentrically surrounds the central axis of the housing, etc. Arranged annularly at angular intervals (positioned at the apex of the regular hexagon), and the other contact 402g is disposed with its axis aligned with the central axis of the housing 401. Yes.

  A protrusion 407 is formed on a part of the inner periphery of the housing 401 so as to be fitted in a groove provided on the outer periphery of the insertion plug when the insertion plug (not shown) is inserted to position the insertion plug in the circumferential direction. . In addition, when the cap is screwed to the opening end of the housing, the waterproof cap 406 is interposed between the end portion of the housing and the inner surface of the cap 406 so that the liquid tightness of the coupling portion between the cap 406 and the housing is provided. An O-ring 408 to be mounted is attached.

  The illustrated metal outlet 4 is arranged in a state of penetrating through a mounting hole 301 provided in the side wall of the case 3 of the electric device, and its flange 401b is fastened to the side wall of the case 3 with a screw (not shown). Thus, the case 3 is fixed.

  In this embodiment, one end of secondary coils L2u and L2w of current transformers CTu and CTw, one end of secondary coil L2z of zero-phase current transformer ZCT, one end of primary coil L1p of instrument transformer PT, One end of the secondary coil L2p is connected through the electric wire 5 to the contacts 402d and 402e grounded through the ground wire. The other ends of the secondary coils L2u and L2w of the current transformers CTu and CTw are connected to the contacts 402a and 402b through the individual electric wires 5, respectively, and the other end of the secondary coil L2p of the instrument transformer PT and the zero phase change. The other end of the secondary coil L2z of the flow device ZCT is connected to the contacts 402c and 402f through the individual electric wires 5, respectively. The contact 402g at the center of the outlet 4 is a play contact that is not connected to any part.

  When supplying the output of the current transformers CTu to CTw, the output of the instrument transformer PT and the output of the zero-phase current transformer ZCT to an external measurement circuit, an insertion plug attached to the end of a measurement cable (not shown) Is inserted into the housing 401 of the metal outlet 4, and the contacts 402a to 402f of the metal outlet 4 are brought into contact with the corresponding male contacts provided on the plug.

  In the present embodiment, when an insertion plug (not shown) is removed from the outlet 4, a plurality of contacts 402 a provided in the outlet 4 are inserted into the outlet 4 instead of the insertion plug. Or the short circuit plug 6 for current transformer protection which short-circuits between 402f is provided.

  As shown in FIGS. 3 to 5, the short-circuit plug 6 used in this embodiment is a male short-circuit contact whose one end is brought into contact with the outlet-side contacts 402 a to 402 f in the outlet body housing 401. 601a to 601f and a short-circuit plate 602 for electrically connecting the short-circuit contacts 601a to 601f to each other on the other end side of the short-circuit contacts 601a to 601f. A shorting plug main body 603 arranged in a state directed toward the opening of the socket, and an insulating plate 604 arranged so as to overlap the shorting plate 602 so as to cover the end face of the shorting plate 602 facing the opening of the housing 401 of the outlet main body. , The opening of the housing 401 from the insulating plate 604 And an insulating knob 605 which is fixed relative to the short-circuit plug body 603 is provided so as to protrude to the side. In this example, the insulating plate 604 forms an insulating portion that covers the end surface of the short-circuit plug body 603. The short-circuit plug 6 is configured to have a size that can be accommodated in the housing 401 of the outlet body in a state where the opening is closed by the cap 406.

  In the illustrated example, the short-circuit plate 602 is made of a disk having an outer diameter smaller than the inner diameter of the housing 401 so that the short-circuit plate 602 can be inserted into the housing 401 of the outlet body, and one end side is respectively connected to the outlet contacts 402a to 402f. The short-circuit contacts 601a to 601f to be brought into contact are formed in a rod shape from a material having good conductivity. The short-circuit contacts 601a to 601f are annular at equal angular intervals so that they can be aligned with the outlet side contacts 402a to 402f, respectively, with their respective axes oriented in a direction perpendicular to the plate surface of the short-circuit plate 602. And the other end of each is joined to one end face 602a of the short-circuit plate 602 by brazing or welding.

  The insulating plate 604 is made of a disk-shaped insulating member having the same outer diameter as that of the short-circuit plate 602, and is arranged in a state of being overlapped with the other end surface 602 b of the short-circuit plate 602 facing the opening side of the housing 401. Yes. A knob mounting hole 602c and a knob through hole 604c that are aligned with each other are formed at the center of the short-circuit plate 602 and the insulating plate 604, respectively.

  The knob 605 of the short-circuit plug is formed to have a cylindrical shape, and is attached to the short-circuit plate 602 through the knob attachment hole 602c and the knob through hole 604c. Short-circuit contacts 601a to 601f in contact with the outlet side contacts 402a to 402f are provided on the outer peripheral portion of the knob 605 disposed in the knob mounting hole 602c and the inner peripheral portion of the knob mounting hole 602c. In order to pull out from 402a thru | or 402f, when the knob 605 is pulled by the opening part side of the housing of an outlet body, it engages with each other and the engaging part which prevents the knob 605 from coming out of the knob attachment hole 602c is provided. ing.

  In the illustrated example, a flange portion 605a is formed at the end of the knob 605 on the short-circuit contact 601a to 601f side, and the enlarged diameter portion 602c1 is fitted to the end of the knob mounting hole 602c on the short-circuit contact side. Is formed. By forming the enlarged diameter portion 602c1, the step portion formed on the inner periphery of the knob mounting hole 602c and the flange portion 605a of the knob 605 constitute the engaging portion, and these engaging portions engage with each other. This prevents the knob from coming off.

  The knob 605 has a length such that approximately half of the knob 605 protrudes outward from the insulating plate 604 in a state of being attached to the short-circuit plate 602 as described above, and a portion protruding from the insulating plate 604 of the knob 605 A ring 606 formed by forming a metal wire into a ring shape is loosely fitted into a hole 605b provided through the wire in a direction orthogonal to the axial direction of the short-circuit contacts 601a to 601f. . The illustrated ring 606 is formed by winding a metal wire in a coil shape for two turns and forming a ring shape, and has an outer diameter larger than the inner diameter of a knob through-hole 604 c provided in the insulating plate 604. . The ring 606 prevents the insulating plate 604 from being detached from the knob 605.

  In this embodiment, when the opening of the housing 401 of the outlet body is closed by the cap 406 with the short-circuit contacts 601a to 601f being in contact with the outlet-side contacts 402a to 402f, respectively, it is shown in FIG. In this way, the length of the knob 605 is set so that the knob 605 contacts the inner surface of the cap 406, and when the knob 605 contacts the inner surface of the cap 406, the short-circuit plug 6 is connected to the outlet side contacts 402a to 402f. Is prevented from coming off.

  A concave portion 607 for fitting a protrusion 407 provided on the housing 401 of the outlet is formed on the outer periphery of the short-circuit plate 602 and the insulating plate 604 of the short-circuit plug 6.

  When the shorting plug 6 is inserted into the outlet 4 and the shorting contacts 601a to 601f are brought into contact with the contacts 402a to 402f of the outlet, a series of contacts of the outlet is made by the shorting contacts 601a to 601f and the shorting plate 602. Since the children 402a to 402f are short-circuited with each other, the secondary side of the current transformers CTu and CTw and the zero-phase current transformer ZCT and the secondary side of the instrument transformer PT are held short-circuited. Each current transformer and instrument transformer are protected.

  In the above embodiment, when the waterproof cap 406 is attached to the outlet 4 after the short-circuit plug 6 is connected to the outlet, the knob 605 of the short-circuit plug 6 comes into contact with the inner surface of the cap 406 so that the short-circuit plug 6 is connected to the outlet side. In order to prevent the contact elements 402a to 402f from coming off, the state where the secondary side or the like of the current transformer is short-circuited can be stably maintained for a long period of time. In this embodiment, since the ring 606 is attached to the knob 605, the shorting plug can be connected by pulling the ring by pinching with the finger or by pulling the tool by pulling the tip of an appropriate tool on the ring. It can be easily pulled out from a metal outlet. Therefore, in order to allow the shorting plug to be accommodated in a narrow space in the outlet, even if the protrusion length of the knob 605 has to be shortened, the operation of removing the shorting plug can be easily performed. it can.

  6 to 8 show another embodiment of the present invention. In this embodiment, the insulating plate 604 and the knob 605 ′ are made of an insulating material having elasticity such as rubber, and the knob 605 ′ is integrally formed on the insulating plate 604. The insulating plate 604 integrally has a projecting portion 604d projecting toward the short-circuit plate 602, and the projecting portion 604d is press-fitted into an insulating plate mounting hole 602c 'provided in the short-circuit plate 602. Is attached.

  Short-circuit contacts 601a to 601f are in contact with the outlet side contacts 402a to 402f on the outer peripheral portion of the protrusion 604d that is press-fitted into the insulating plate mounting hole 602c ′ and the inner peripheral portion of the insulating plate mounting hole 602c ′. When the knob 605 'is pulled toward the opening side of the housing 401 of the outlet body in the state of being in contact, an engaging portion is provided that engages with each other and prevents the protruding portion 605d from coming out of the insulating plate mounting hole 602c'. It has been.

  In the example shown in the drawing, an enlarged diameter portion 604d1 is formed at the tip of the protrusion 604d, and the protrusion 604d is formed on the inner periphery of the opening end on the short-circuit contact side of the insulating plate mounting hole 602c ′ provided in the short-circuit plate. An enlarged diameter portion 602c1 ′ for fitting the enlarged diameter portion 604d1 is formed, and a step portion formed on the inner periphery of the attachment hole 602c ′ by forming the enlarged diameter portion 602c1 ′ in the insulating plate attachment hole 602c ′; The enlarged diameter portion 604d1 of the protruding portion 604d constitutes the engaging portion.

  The knob 605 ′ is formed in an annular shape (in the shape of glasses), and as shown in FIG. 6, the short-circuit contacts 601 a to 601 f are in contact with the outlet side contacts 402 a to 402 f, respectively. When the opening 401 is closed by the cap 406, the knob 605 is disposed so that the knob 605 'is compressed between the inner surface of the cap 406 and the insulating plate 604 as shown in FIG. The protrusion length from the insulating plate is set. As described above, when the knob 605 ′ is disposed in a compressed state between the inner surface of the cap 406 and the insulating plate 604, it is possible to prevent the short-circuit plug 6 from being detached from the outlet-side contactor. Therefore, the state where the secondary side of the current transformer or the like is short-circuited can be kept stable for a long period of time. Further, when the knob 605 'is formed in an annular shape, when removing the short-circuit plug, the short-circuit plug is pulled out by pinching and pulling the knob 605' or pulling the tool by pulling the appropriate tool on the ring. Therefore, the operation of removing the shorting plug can be easily performed.

  Other configurations of the embodiment shown in FIGS. 6 to 7 are the same as those of the embodiment shown in FIGS.

  In each of the above embodiments, the female contact is used as the outlet-side contact, but the present invention can also be applied when a male contact is used as the outlet-side contact.

  FIG. 8 shows an embodiment in which male contacts are used as the outlet-side contacts 402a ′ to 402g ′. The outlet-side contacts 402a ′ to 402g ′ are arranged in the same manner as in the previous embodiment. The housing 401 is supported via an insulating support 403 ′. In order to give elasticity to the distal end side of the outlet side contacts 402a ′ to 402g ′, a split s is provided on the respective distal end side of the outlet side contacts 402a ′ to 402g ′.

  The shorting plug 6 is disposed toward the opening side of the housing 401 of the outlet body and the conductive shorting block 602 ′ having holes in which the outlet side contacts 402 a ′ to 402 g ′ are slidably fitted. An insulating plate 604 ′ provided so as to cover the end face of the short-circuit block 602 ′ and mechanically coupled to the short-circuit block 602 ′, and a columnar knob 605 provided integrally with the insulating plate 604 ′. A ring 606 is loosely fitted in a hole 605b penetrating 605 in a direction perpendicular to the axial direction. In this embodiment, the holes provided in the short-circuit block 602 ′ for fitting the outlet side contacts 402a ′ to 402g ′ respectively constitute the short-circuit contacts 601a ′ to 601g ′, and the short-circuit block 602 ′ A short-circuit plug body 603 is configured.

  In the above description, the case where the main body of the electric device is a switch is taken as an example. However, the present invention is not limited to the switch, and the present invention is widely applied to a case where a current transformer is built in a case housing the electric device main body. Can be applied.

  When the knob 605 is formed in a columnar shape as in the embodiment shown in FIGS. 2 to 5 and the embodiment shown in FIG. 8, the ring 606 is fitted into the through hole provided in the knob 605. Then, the operation of pulling out the short-circuit plug from the outlet can be easily performed. However, the present invention is not limited to the case where the ring is attached to the knob as described above. The ring 606 is omitted, and a jig (not shown) is inserted into a through-hole provided in the knob 605 so that the short-circuit plug is disconnected from the outlet. You may make it pull out. In the embodiment shown in FIGS. 2 to 5, when the ring 606 is omitted, the insulating plate 604 is bonded to the short-circuit plate 602 in order to prevent the insulating plate from being detached from the knob 605.

It is a circuit diagram showing the electric composition of the electric equipment concerning the embodiment of the present invention. It is sectional drawing which showed the state which connected the shorting plug to the outlet socket of the electric equipment concerning this embodiment. It is the III-III sectional view taken on the line of FIG. It is sectional drawing which showed the outlet socket used by this embodiment, the short-circuit plug inserted in this outlet socket, and the waterproof cap attached to this outlet socket. FIG. 5 is a front view of the short-circuit plug as viewed from the direction of the VV line in FIG. 4. It is sectional drawing which showed the state which connected the shorting plug to the outlet socket of the electric equipment concerning other embodiment of this invention. It is sectional drawing which showed the electrical outlet used in the embodiment, the short-circuit plug inserted in this electrical outlet, and the waterproof cap attached to this electrical outlet. It is sectional drawing which showed the state which connected the shorting plug to the outlet socket of the electric equipment concerning further another embodiment of this invention.

Explanation of symbols

1 Switch CTu, CTw Current Transformer ZCT Zero Phase Current Transformer PT Instrument Transformer 3 Case 4 Metal Outlet 401 Outlet Body Housing 402a to 402f, 402a 'to 402f' Outlet Side Contact 406 Waterproof Cap 6 Shorting Plug 601a 601f, 601a 'to 601g' Short-circuit contact 602 Short-circuit plate 602 'Short-circuit block 603 Short-circuit plug body 604, 604' Insulation plate 605, 605 'Knob 605b Through-hole 606 Ring

Claims (9)

A case containing an electric device main body, a current transformer which is housed in the case together with the electric device main body, and is provided to measure an alternating current flowing through a circuit configured in the case; A plurality of outlet side contacts including a contact connected to one end of the secondary coil of the container and a contact connected to the other end of the secondary coil, and an outlet attached to the case. The outlet includes a plurality of outlet side contacts in a housing having an opening at one end for receiving a plug having a plurality of plug side contacts connected to the plurality of outlet side contacts, respectively. When the outlet body has a structure in which the axis is accommodated in the axial direction of the housing, and the plug is removed from the outlet body And a cap for closing the opening of the housing of the outlet body, the current transformer built-in electric device output of each current transformer is taken out to the outside through the connected mating plug in the outlet and said outlet,
A shorting plug that is inserted into the housing of the outlet body in a state where the plug is removed, and short-circuits between the plurality of outlet side contacts;
The shorting plug is disposed toward the opening side of the housing of the outlet body, and the shorting plug body having a plurality of shorting contacts that respectively contact the plurality of outlet side contacts in the outlet housing. An insulating portion that covers an end face of the short-circuit plug body, and an insulating knob that is provided so as to protrude from the insulating portion toward the opening of the housing and is fixed to the short-circuit plug body.
The shorting plug has a size that fits within the housing of the outlet body in a state where the opening is closed by the cap;
Electrical equipment with built-in current transformer characterized by A case containing an electric device main body, a current transformer which is housed in the case together with the electric device main body, and is provided to measure an alternating current flowing through a circuit configured in the case; An outlet having a plurality of outlet-side contacts including a female contact connected to one end of a secondary coil of the container and a female contact connected to the other end of the secondary coil, and attached to the case The outlet includes a plurality of male plug-side contacts respectively connected to the plurality of outlet-side contacts, and the plurality of outlets in a housing having an opening for receiving an insertion plug at one end. An outlet body having a structure in which the outlet side contacts are accommodated in a state where the respective axis lines are directed in the axial direction of the housing, and the plug is removed from the outlet body. A cap with which the opening of the housing of the outlet body is closed when in a state, and the output of each current transformer is taken out through the outlet and an insertion plug connected to the outlet. In electrical equipment,
A shorting plug that is inserted into the housing of the outlet body in a state where the plug is removed, and short-circuits between the plurality of outlet side contacts;
The short-circuit plug includes a plurality of male short-circuit contacts whose one end is brought into contact with the plurality of outlet-side contacts in the outlet housing, and the plurality of short-circuits on the other end of the plurality of short-circuit contacts. A short-circuit plug body having a short-circuit plate provided so as to be electrically connected to each other and disposed toward the opening of the outlet body housing, and toward the opening side of the outlet body housing. An insulating plate disposed on the shorting plate so as to cover the end surface of the shorting plate, and fixed to the shorting plug body so as to protrude from the insulating plate toward the opening of the housing. With an insulated knob,
The shorting plug has a size that fits within the housing of the outlet body in a state where the opening is closed by the cap;
Electrical equipment with built-in current transformer characterized by The knob of the short-circuit plug is formed in a cylindrical shape, and penetrates the knob attachment hole provided through the short-circuit plate and the knob penetration hole provided in the insulating plate so as to be aligned with the knob attachment hole. Attached to the short-circuit plate
An engaging portion that engages with each other and prevents the knob from coming out of the knob mounting hole on the outer peripheral portion of the knob disposed in the knob mounting hole and the inner peripheral portion of the knob mounting hole. Is provided,
The knob is in contact with the inner surface of the cap body when the opening of the housing of the outlet body is closed by the cap in a state where the plurality of short-circuit contacts are in contact with the plurality of outlet side contacts, respectively. The short-circuit plug is provided to prevent the short-circuit plug from coming off from the outlet-side contact.
The electric device with a built-in current transformer according to claim 2. A ring is loosely fitted into a hole provided through the knob in a direction perpendicular to the axial direction of the short-circuit contact;
The ring has an outer diameter larger than an inner diameter of a knob through-hole provided in the insulating plate;
The electric device with a built-in current transformer according to claim 3. The insulating plate and the knob are made of an insulating material having elasticity, and the knob is integrally formed on the insulating plate,
The insulating plate has a protruding portion protruding to the short-circuit plate side, and the protruding portion is attached to the short-circuit plate in a state of being press-fitted into an insulating plate mounting hole provided in the short-circuit plate,
The outer peripheral portion of the protruding portion that is press-fitted into the insulating plate mounting hole and the inner peripheral portion of the insulating plate mounting hole are engaged with each other to prevent the protruding portion from coming out of the insulating plate mounting hole. An engaging part for blocking,
The knob is electrically insulated from the inner surface of the cap when the opening of the housing of the outlet body is closed by the cap with the plurality of short-circuit contacts being in contact with the plurality of outlet-side contacts, respectively. Disposed in a compressed state between the plate and the shorting plug so as to prevent the plug from being removed from the outlet-side contact;
The electric device with a built-in current transformer according to claim 2. A case containing an electric device main body, a current transformer which is housed in the case together with the electric device main body, and is provided to measure an alternating current flowing through a circuit configured in the case; A plurality of outlet side contacts including a contact connected to one end of the secondary coil of the container and a contact connected to the other end of the secondary coil, and an outlet attached to the case. The outlet includes a plurality of outlet side contacts in a housing having an opening at one end for receiving a plug having a plurality of plug side contacts connected to the plurality of outlet side contacts, respectively. When the outlet body has a structure in which the axis is accommodated in the axial direction of the housing, and the plug is removed from the outlet body A socket for closing the opening of the housing of the outlet body, and the outlet of the electrical device with a built-in current transformer, in which the output of each current transformer is taken out through the outlet and an insertion plug connected to the outlet. A short-circuit plug for protecting a current transformer that is plugged into the outlet instead of the plug to protect the current transformer when the plug is removed from the plug;
A short-circuit plug body having a plurality of short-circuit contacts that respectively contact the plurality of outlet-side contacts in the outlet housing, and an end face of the short-circuit plug body arranged toward the opening side of the outlet body housing And an insulating knob provided so as to protrude from the insulating part to the opening side of the housing and fixed to the short-circuit plug body,
The shorting plug has a size that fits within the housing of the outlet body in a state where the opening is closed by the cap;
A short-circuit plug for current transformer protection. A case containing an electric device main body, a current transformer which is housed in the case together with the electric device main body, and is provided to measure an alternating current flowing through a circuit configured in the case; A plurality of female outlet side contacts including a female contact connected to one end of a secondary coil of the container and a female contact connected to the other end of the secondary coil, and attached to the case An outlet for receiving an insertion plug having a plurality of male plug-side contacts respectively connected to the plurality of outlet-side contacts. An outlet body having a structure in which the plurality of outlet-side contacts are accommodated in a state where respective axes are directed in the axial direction of the housing, and an insertion plug is removed from the outlet body. A cap that closes the opening of the housing of the outlet body when in a closed state, and outputs the output of each current transformer to the outside through the outlet and an insertion plug connected to the outlet In order to protect the current transformer when the plug is removed from the outlet of the built-in electric device, a short-circuit plug for current transformer protection inserted into the outlet instead of the plug.
A plurality of short-circuit contacts whose one end is brought into contact with each of the plurality of outlet-side contacts in the outlet housing, and the plurality of short-circuit contacts are electrically connected to each other at the other end of the plurality of short-circuit contacts. A short-circuit plug body having a short-circuit plate provided to be connected and arranged toward an opening of the housing of the outlet body, and an end surface of the short-circuit plate facing the opening of the housing of the outlet body is covered. An insulating plate disposed to overlap the shorting plate, and an insulating knob provided so as to protrude from the insulating plate to the opening side of the housing and fixed to the shorting plug body,
The shorting plug has a size that fits within the housing of the outlet body in a state where the opening is closed by the cap;
A short-circuit plug for current transformer protection. The knob of the short-circuit plug is formed in a columnar shape, and is attached to the short-circuit plate in a state of penetrating a knob attachment hole provided through the short-circuit plate and a knob through-hole provided in the insulating plate,
An engaging portion that engages with each other and prevents the knob from coming out of the knob mounting hole on the outer peripheral portion of the knob disposed in the knob mounting hole and the inner peripheral portion of the knob mounting hole. Is provided,
The knob is provided to contact the cap when the opening of the housing of the outlet body is closed by the cap and prevent the short-circuit plug from being detached from the outlet-side contact,
A ring is loosely fitted into a hole provided through the knob in a direction perpendicular to the axial direction of the short-circuit contact;
The ring has an outer diameter larger than an inner diameter of a knob through-hole provided in the insulating plate;
The shorting plug for current transformer protection according to claim 7 characterized by things. The insulating plate and the knob are made of an insulating material having elasticity, and the knob is integrally formed on the insulating plate,
The insulating plate has a protruding portion protruding to the short-circuit plate side, and the protruding portion is attached to the short-circuit plate in a state of being press-fitted into an insulating plate mounting hole provided in the short-circuit plate,
The outer peripheral portion of the protruding portion that is press-fitted into the insulating plate mounting hole and the inner peripheral portion of the insulating plate mounting hole are engaged with each other to prevent the protruding portion from coming out of the insulating plate mounting hole. An engaging part for blocking,
The knob is disposed in a compressed state between the cap and the insulating plate when the opening of the housing of the outlet body is closed by the cap, and the shorting plug is connected to the outlet-side contactor. Being provided to prevent it from coming off,
The shorting plug for current transformer protection according to claim 7 characterized by things.

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