JP2013005671A - Electrical apparatus with current transformer, and current transformer protecting short-circuit element used for electrical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical equipment with a short-circuit element that short-circuits a secondary side of a current transformer for protecting the current transformer during non-use thereof.SOLUTION: A receptacle 4 having a contact connected to a secondary coil of a current transformer is attached to a case 3 accommodating an electrical apparatus body together with the current transformer therein. A short-circuit element 10 has a structure that accommodates a short-circuit element body 11 including a plurality of short-circuit contact pieces 11a-11g connected to a plurality of contacts of the receptacle 4 in an insulation cap 12. The insulation cap 12 of the short-circuit element 10 has a shape that overlies an insulation support 403 holding the contact of the receptacle. When a metal cap 20 is screw-connected to a receptacle body 401, the insulation cap 12 of the short-circuit element 10 is received within the metal cap 20 to thereby insulate between the short-circuit element body 11 and the metal cap 20.

Description

  The present invention relates to an electric device including a current transformer that detects an alternating current flowing through an electric device main body housed in a case, and a current transformer protection short-circuit used for protecting the current transformer of the electric device. Is.

  When it is necessary to measure the alternating current flowing through the electrical equipment body in the case in the electrical equipment in which the electrical equipment body is accommodated in the case, the electrical equipment is provided with a current transformer, and the output of the current transformer Is supplied to an external device such as a relay box through an instrumentation cable.

  For example, in a circuit breaker installed in a power distribution system, a current transformer for detecting at least two-phase line current is housed in a case housing a circuit breaker, and the secondary side of these current transformers is in the case. Connected to the attached receptacle. A plug and a receptacle are attached to one end and the other end of an instrumentation cable that supplies the output of the current transformer to an external device, respectively, and the plug at one end of the instrumentation cable is attached to the case of the electrical device The receptacle attached to the other end of the instrumentation cable is connected to a plug attached to the relay box, for example.

  The current transformer includes 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. Current transformers include a through type that uses a through conductor arranged in a state of passing through a core as a primary conductor, and a wound type that uses a coil wound around a core as a primary conductor.

  There are a through-type current transformer that includes a dedicated through conductor as a conductor that penetrates the core, and a through-current transformer that uses a conductor through which a current to be measured flows. In the case of measuring a large current in a power circuit, in most cases, a through-type current transformer is used. However, the current transformer provided in the electrical equipment targeted by the present invention may be of any type. .

  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 measuring circuit with a burden resistance on the external device side such as a relay box and connecting the measuring circuit to the current transformer through an instrument cable, the secondary side of the current transformer is opened. Is prevented.

  As described above, when the current transformer provided in the electric device is connected to the burden resistance in the external device through the instrumentation cable, the current transformer is not normally opened. However, when it is assumed that the electrical device is separated from the external device and used alone, for example, it is assumed that the electrical device is installed and operated in the power distribution system prior to the installation of the external device. In some cases, it is necessary to provide some protection means in case the secondary side of the current transformer 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. However, in such a configuration, if any one of a large number of diodes is damaged, the protective operation is not performed, and there is a concern about reliability.

  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. A protection device has also been proposed in which the sides are short-circuited. However, in the case of such a protective device, 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 electric device. Not only is the internal structure complicated, but the cost of electrical equipment is inevitable.

  Therefore, as shown in Patent Document 3, the present applicant has removed the plug attached to the instrumentation cable from the receptacle attached to the case of the electric device in order to take out the output of the current transformer. In this state, an electrical device has been proposed in which a short-circuit (short-circuit plug) that short-circuits between the contacts of the receptacle is connected to the receptacle and the secondary coil of the current transformer is short-circuited by the short-circuit.

  A short-circuit used in an electric device disclosed in Patent Document 3 includes a short-circuit body having a plurality of short-circuit contacts that respectively contact a plurality of contacts of a receptacle, and an insulating member that covers an end surface of the short-circuit body And an insulating knob connected to the short-circuit body, and when the metal cap is attached to the receptacle, the size fits in the space formed between the metal cap and the receptacle. It is formed to have.

JP-A-10-274663 JP 2007-35808 A JP 2010-10322 A

  As shown in Patent Document 3, when the plug attached to the instrumentation cable is in a state of being removed from the receptacle, a short circuit is connected to the receptacle, and this short circuit causes the secondary side of the current transformer to be connected. By short-circuiting the current transformer, it is possible to reliably protect the current transformer without using a protection circuit or a lightning arrester, with a simple structure, and without worrying about failure.

  However, since the short circuit used in the electric device disclosed in Patent Document 3 has an exposed conductive portion, a surge enters from the secondary side of the current transformer and the short circuit When a high voltage is applied to a nearby ground potential part (metal part of a metal cap or receptacle), there is a risk of dielectric breakdown between the short-circuiting element and the ground potential part, resulting in a problem with reliability. there were.

  In order to increase the insulation strength between the short circuit element and the ground potential part, it is conceivable to configure the receptacle and the metal cap so as to secure a sufficient insulation distance between the short circuit element and the ground potential part. Such a configuration is not preferable because the receptacle and the metal cap increase in size.

  The object of the present invention is to increase the insulation between the short-circuiting element for short-circuiting the contact of the receptacle and the ground potential portion in the vicinity thereof without increasing the size of the receptacle or the metal cap, thereby improving the reliability. An object of the present invention is to provide an electrical device with a built-in current transformer.

  Another object of the present invention is to short-circuit the contacts of the receptacle attached to the case of the electrical device with built-in current transformer without impairing the reliability and without increasing the size of the receptacle or the metal cap. An object of the present invention is to provide a current transformer protection short-circuiting element capable of protecting a current transformer in a case.

  The present invention includes a plurality of contacts including an electric device main body housed in a case, a current transformer for measuring an alternating current flowing through the electric device main body, and a contact for taking out an output of a secondary coil of the current transformer. A receptacle formed by supporting an insulating support of a contact assembly having a structure in which a cross-sectional outline is circular in a state where the respective axes are parallel to each other in a circular shape and supported on a receptacle body made of a conductive material, and the receptacle A metal cap that is screwed to the body and covers the contact assembly of the receptacle, and the plug contact is connected to the contact of the receptacle with the metal cap removed, and the output of the current transformer through the plug and the receptacle Is intended for electrical equipment that is supplied to external equipment.

  In the present invention, one of a pair of elements constituting a connector for electrical connection using a female contact and a male contact removably connected to the female contact is provided. It is called a receptacle and the other is called a plug. The contact provided on the receptacle may be female, the contact provided on the plug may be male, the contact provided on the receptacle may be male, and the contact provided on the plug side may be female. However, the contact provided in the receptacle is provided in a state of being accommodated in the insulating support.

  In the present invention, a plurality of short-circuiting contacts, each of which is in contact with a plurality of contacts that need to be short-circuited to each other in the receptacle with the plug removed, are connected to each other. An electrically conductive short circuit body having a structure electrically connected to the insulation body, and a bottomed cylindrical shape covering the insulating support of the contact assembly, and holding the short circuit body in the state of being accommodated inside A short circuit having a cap is provided. Then, each short-circuit contact of the short-circuit is brought into contact with a corresponding contact of the receptacle from which the plug has been removed, and the metal cap is screwed to the receptacle body in a state where the insulating cap is placed on the insulating support of the contact assembly. In this case, the insulating cap of the short circuit is received in the metal cap and is configured to insulate between the short circuit body and the ground potential portion including the metal cap.

  With the above configuration, each short-circuit contact of the short-circuit is brought into contact with the corresponding contact of the receptacle from which the plug has been removed, and the metal cap is placed in the receptacle while the insulating cap is placed on the insulating support of the contact assembly. When screwed to the body, the insulation cap can insulate between the short-circuit body and the ground potential part, so as to insulate between the short-circuit body and the ground potential part by an air gap, Without increasing the size of the receptacle and the metal cap, it is possible to enhance the insulation between the short-circuiting element and the surrounding ground potential portion, thereby improving the reliability.

  In a preferred aspect of the present invention, the rear end portions of the plurality of short-circuit contacts of the short-circuit body are electrically and mechanically connected to the flange plate made of a conductive material, whereby the plurality of short-circuit contacts are integrated. It becomes. The short-circuit insulating cap is made of an insulating material having elasticity, and a short-circuit engaging groove is provided on the inner periphery of the cylindrical portion so as to be positioned near the bottom of the cylindrical portion of the insulating cap. In this case, the short-circuit body is housed in the insulating cap, and the portion near the outer periphery of the flange plate is held in the insulating cap by being fitted in the short-circuit locking groove. In this aspect, at least one air vent groove extending over the entire length of the cylindrical portion in the axial direction is formed on the outer periphery of the cylindrical portion of the insulating cap, and the receptacle body of the receptacle to which the short-circuit is connected has a metal When screwing the cap, the air in the space formed between the bottom of the cylindrical portion of the insulation cap of the short-circuiting element received inside the metal cap and the metal cap can be discharged to the outside through the air vent groove. It is configured.

  As described above, the insulating cap is made of an insulating material having elasticity, and the portion near the outer periphery of the flange plate of the short-circuiting body is in the short-circuiting locking groove formed on the inner periphery of the cylindrical portion of the insulating cap. If the structure is such that the main body of the short-circuit is held by the insulating cap by fitting, the assembly of the short-circuit can be facilitated. Moreover, when comprised in this way, since the whole short circuit can be hold | maintained, without removing a short circuit body main body from an insulation cap by grasping and holding the part near the bottom of the cylindrical part of an insulation cap, a short circuit Even if an insulating knob is not provided, the short circuit can be attached and detached, and the structure of the short circuit can be simplified.

  In addition, as described above, if at least one air vent groove extending over the entire length of the cylindrical portion in the axial direction is formed on the outer periphery of the cylindrical portion of the insulating cap, the receptacle body of the receptacle to which the short-circuiting element is connected When screwing the metal cap, the air in the space formed between the bottom of the insulation cap cylindrical part and the metal cap received inside the metal cap can be discharged to the outside through the air vent groove. Therefore, the metal cap can be easily attached. Therefore, it is possible to connect the short-circuit provided with the insulating cap to the receptacle without hindering the attachment of the metal cap.

  In another preferred aspect of the present invention, with the short-circuit connected to the receptacle, the portion near the bottom of the cylindrical portion of the insulating cap of the short-circuit is disposed in a state of protruding outward from the end face of the receptacle body. Further, the dimensions of the contact assembly of the receptacle and the dimensions of the short circuit are set.

  As described above, when the dimensions of the contact assembly of the receptacle and the dimensions of the short-circuit are set, with the short-circuit connected to the receptacle, at least the bottom portion of the cylindrical portion of the short-circuit insulation cap is connected to the receptacle. Since it can be arranged in a state of protruding outward from the end surface of the body, the part near the bottom of the insulation cap of the short circuit together with the short circuit body inside the hand is gripped by hand or a tool, It can be easily attached and detached. Therefore, even if the short-circuit element is not provided with a knob made of an insulating material, the short-circuit element can be easily attached and detached, and the structure of the short-circuit element can be simplified.

  The receptacle for connecting the short circuit may be attached to the other end of the instrumentation cable, one end of which is electrically connected to the secondary coil of the current transformer, and the case of the electrical device provided with the current transformer It may be attached to.

  The present invention also includes a plurality of electrical equipment bodies housed in a case, a current transformer for measuring an alternating current flowing through the electrical equipment body, and a contact for taking out an output of a secondary coil of the current transformer. A receptacle formed by supporting the insulating support of a contact assembly having a structure in which a contact is supported in an insulating support having a circular cross-section in a state where the respective axes are parallel to each other on a receptacle body made of a conductive material. And a metal cap screwed to the receptacle body to cover the contact assembly of the receptacle, and a contact of the plug is connected to the contact of the receptacle with the metal cap removed, the plug and the The receptacle of an electrical device in which the output of the current transformer is supplied to an external device through the receptacle. Wherein said Target current transformer protective shorting terminal to be connected to the receptacle in place of the plug in order to protect the current transformer when the plug is disconnected from.

  The short-circuiting device according to the present invention includes a plurality of short-circuiting contacts that respectively contact a plurality of contacts that need to be short-circuited to each other in the receptacle with the plug removed, and the plurality of short-circuiting contacts are mutually connected. A metal short-circuit body that is electrically connected to the body, and a bottomed cylindrical shape that covers the insulation support of the receptacle contact assembly and holds the short-circuit body inside Each of the short-circuit contacts of the short-circuit body is brought into contact with a corresponding contact of the receptacle from which the plug has been removed, and the insulating cap is put on the exposed portion of the contact assembly. When the metal cap is screwed to the receptacle body, the insulation cap is received in the metal cap to insulate between the short-circuit body and the metal cap It has been made.

  In a preferred aspect of the present invention, the plurality of short-circuit contacts of the short-circuit body have a structure in which the respective rear end portions are electrically and mechanically connected to a flange plate made of a conductive material and integrated. The insulating cap is made of an insulating material having elasticity, and a short-circuiting-engaging groove portion is provided around the inner periphery of the cylindrical portion so as to be positioned near the bottom portion of the cylindrical portion of the insulating cap. In this case, the short-circuit body is accommodated in the insulating cap, and the portion closer to the outer periphery of the flange plate is fitted into the short-circuit locking groove portion and held by the insulating cap. Also, in this aspect, at least one air vent groove extending over the entire length of the cylindrical portion in the axial direction is formed on the outer periphery of the cylindrical portion of the insulating cap, and the metal cap is screwed into the receptacle body of the receptacle to which the short circuit is connected. When joining, the air in the space formed between the bottom part of the cylindrical part of the insulating cap of the short circuit received inside the metal cap and the metal cap can be discharged to the outside through the air vent groove. Yes.

  According to the present invention, each short-circuit contact of the short-circuit is brought into contact with a corresponding contact of the receptacle from which the plug has been removed, and the metal cap is placed on the receptacle body in a state where the insulation cap is placed on the insulating support of the contact assembly. When the screw is connected to the connector, the insulation cap can insulate the short-circuit body from the ground potential part, so that the receptacle is insulated from the short-circuit body and the ground potential part by an air gap. In addition, without increasing the size of the metal cap, it is possible to enhance the insulation between the short-circuiting element and the surrounding ground potential portion to improve the reliability.

  In the present invention, the insulating cap is made of an insulating material having elasticity, and the portion near the outer periphery of the flange plate of the short-circuiting body is formed in the short-circuiting engaging groove formed on the inner periphery of the cylindrical portion of the insulating cap. When the structure is such that the short-circuit body is held by the insulating cap by fitting, the assembly of the short-circuit can be facilitated. Moreover, when comprised in this way, the short circuit body whole can be hold | maintained, without removing a short circuit body main body from an insulation cap by hold | gripping and hold | maintaining the part near the bottom part of the cylindrical part of an insulation cap. Even without providing an insulating knob on the short circuit, the short circuit can be attached and detached, and the structure of the short circuit can be simplified.

  In the present invention, when at least one air vent groove extending over the entire length of the cylindrical portion in the axial direction is formed on the outer periphery of the cylindrical portion of the insulating cap, a metal is attached to the receptacle body of the receptacle to which the short circuit is connected. When the cap is screwed, the air in the space formed between the bottom of the cylindrical portion of the insulating cap of the short circuit received inside the metal cap and the metal cap can be discharged to the outside through the air vent groove. Therefore, it is possible to connect the short-circuit element provided with the insulating cap to the receptacle without hindering the attachment of the metal cap.

It is sectional drawing which showed separately the metal cap used in embodiment of this invention, a short circuiting element, and a receptacle. It is sectional drawing which showed the state which connected the short circuit used in this embodiment to the receptacle with the metal cap before attaching to a receptacle. It is sectional drawing which showed the state which connected the short circuit element to the receptacle used by this embodiment, and also attached the metal cap to the receptacle. It is a top view of the receptacle used by this embodiment. (A) is a top view of the short-circuit main body used in the present embodiment, and (B) is a cross-sectional view taken along line BB in (A). (A) And (B) is the top view and longitudinal cross-sectional view of the insulation cap of the short circuit used in this embodiment, respectively. It is the connection diagram which showed the electrical structure of the electric equipment of this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The electrical device according to the present embodiment is a circuit breaker that is disposed near the end of the high-voltage distribution line in the distribution system and is inserted in series into the distribution line. As shown in FIG. 7, this circuit breaker includes a circuit breaker body 1 having U, V, W three-phase circuit breakers 1 u to 1 w and a three-phase circuit breaker 1 u to 1 w of the circuit breaker body 1. Each of the conductors 2u to 2w connected in series, and the through-type current transformers are provided so that the conductors 2u and 2w are respectively primary conductors and respectively measure the U-phase and W-phase line currents flowing through the conductors 2u and 2w. Devices CTu and CTw. Devices (electric device main bodies) such as the circuit breaker main body 1, the conductors 2u to 2w, and the current transformers CTu and CTw are accommodated in a metal case 3. On the side wall of the case 3, a receptacle 4 ′ constituting a metal connector is attached so that a plug (not shown) attached to an instrumentation cable can be connected from the outside.

  A receptacle 4 'attached to the case 3 includes an insulating support 403' fixed to a receptacle body (not shown) made of a conductive material, and a contact 4a held in the insulating support 403 '. The contacts 4a 'to 4g' are connected to devices in the case 3 through lead wires.

  In the example shown in FIG. 7, the contacts 4b 'and 4g' are connected to both ends of the secondary coil of the current transformer CTu, and the center contact 4a 'is connected to the center tap of the secondary coil of the current transformer CTu. Yes. The contacts 4e 'and 4g' are connected to both ends of the secondary coil of the current transformer CTw, and the contact 4f 'is connected to the center tap of the secondary coil of the current transformer CTw. Further, in the illustrated example, the contacts 4c 'and 4d' are connected to both ends of the trip coil 5 that is excited when the blocking portions 1u to 1w are opened. A diode 6 is connected to both ends of the trip coil 5.

  A plug attached to one end of an unillustrated instrumentation cable is connected to the receptacle attached to the circuit breaker case 3. At the other end of the cable for instrumentation, the receptacle 4 shown in the lowermost part of FIG. 1 and FIG. 4 is attached, and this receptacle 4 is connected to a plug attached to a relay box (not shown), thereby transforming current. The outputs of the secondary coils of the capacitors CTu and CTw are supplied to the circuit in the relay box.

  The receptacle 4 attached to the other end of the instrumentation cable includes a receptacle body 401 made of a conductive material and a contact assembly 402 supported by the receptacle body 401. The receptacle body 401 is formed so that the contour shape of the cross section is circular, and an annular groove 401b is formed on one axial end surface 401a thereof, and a peripheral wall 401c that defines the outer periphery of the groove 401b. A female screw portion 401d used for screwing a metal cap, which will be described later, is formed on the inner peripheral surface of the inner screw surface.

  The contact assembly 402 includes an insulating support 403 and contacts 4 a to 4 g held in the insulating support 403. The insulating support 403 is formed so that the contour shape of the cross section is circular, and the center axis of the insulating support 403 coincides with the center axis of the receptacle body 401, and the portion near the rear end thereof is the receptacle body 401. It is fixed to the inner circumference. In the illustrated example, a neck lower part 403a having a reduced outer diameter is formed in a portion near the rear end of the insulating support 403, and the neck lower part 403a is fitted to the inner peripheral part of the receptacle body 401. It is fixed to the receptacle body 401 by appropriate means.

  The head 403b of the insulating support formed on the distal end side of the neck lower portion 403a of the insulating support 403 is disposed in a state of protruding outward from one axial end surface 401a of the receptacle body 401, and is insulated. An end surface 403 b 1 on the front end side of the head 403 b of the object 403 is disposed at a position beyond the end surface 401 a of the receptacle body 401.

  The insulating support 403 is formed with one through-hole 404a penetrating the central portion in the axial direction, and six axial through-holes 404b to 404g arranged at equal angular intervals around the through-hole 404a. Yes. One female contact 4a is held in the central through hole 404a of the insulating support 403, and six female contacts 4b to 4g are respectively provided in the six through holes 404b to 404g formed around the through hole 404a. Is held. The female contacts 4a to 4g are arranged with their respective tips directed toward the tip surface 403b1 side of the insulating support 403. From the tip surface side of the insulating support 403 to the female contacts 4a to 4g, A corresponding male contact of a plug (not shown) can be inserted and brought into contact. The female contacts 4a to 4g are connected to plug contacts respectively connected to the contacts 4a 'to 4g' of the receptacle 4 'attached to the case 3 through the electric wires 7 in the instrumentation cable.

  A male contact of a plug attached to a relay box (not shown) is connected to the contacts 4a to 4g of the receptacle 4 attached to the other end of the instrumentation cable, and the output of the current transformer is connected to the receptacle 4 and the receptacle. It is supplied to the circuit in the relay box through a connected plug (not shown).

  In this embodiment, when the receptacle 4 attached to the other end of the instrumentation cable is removed from the plug attached to the terminal box, the receptacle 4 is connected to the receptacle 4 instead of the plug. Among the provided contacts, a short circuit 10 is provided for short-circuiting contacts that need to be short-circuited to each other.

  The shorting element 10 used in the present embodiment has a shorted body 11 and a bottomed cylindrical shape that covers the insulating support of the contact assembly, and holds the shorting body 11 accommodated inside. 12.

  As shown in FIGS. 5A and 5B, the short-circuit body 11 is provided corresponding to each of the female contacts 4a to 4g of the receptacle 4, and the distal end side corresponds to the female contacts 4a to 4a. It has a structure in which male short-circuiting contacts 11a to 11g are inserted and connected to 4g, and these short-circuiting contacts are electrically and mechanically connected to each other.

  In the illustrated example, the rear end portions of the short-circuiting contacts 11a to 11g are electrically and mechanically connected to the disk-shaped flange plate 13 made of a conductive material, so that the short-circuiting contacts 11a to 11g are It is integrated.

  The insulating cap 12 is made of an insulating material having elasticity such as rubber, and as shown in FIGS. 6A and 6B, the cylindrical side wall 12a and the axial direction of the side wall 12a. It is formed so as to have a bottomed cylindrical shape integrally provided with a bottom 12b that closes one end of the bottom. On the inner periphery of the side wall 12a of the insulating cap 12, a short-circuit locking groove 12c is provided around the bottom 12b, and the flange plate 13 of the short-circuit body 11 is provided in the short-circuit locking groove 12c. The short-circuit main body 11 is held by the insulating cap 12 by fitting the portion closer to the outer periphery of.

  At least one air vent groove 12d is formed on the outer periphery of the side wall 12a of the insulating cap 12 so as to extend over the entire length of the side wall in the axial direction. In the illustrated example, three air vent grooves 12d extending over the entire length in the axial direction of the side wall portion 12a are formed at intervals of 120 degrees on the outer periphery of the side wall portion 12a.

  The metal cap 20 shown in FIG. 1 to FIG. 3 is screwed and attached to the receptacle body 401 of the receptacle 4 to which the plug 4 is removed from the receptacle 4 and the short-circuiting element 10 is connected. The illustrated metal cap 20 is formed to have a cup-like shape integrally including a cylindrical peripheral wall portion 21 and an end wall 22 formed at one end of the peripheral wall portion 21 in the axial direction. In addition, on the outer periphery of the other end (opening end) in the axial direction of the peripheral wall portion 21, a male screw portion 23 that is screwed into the female screw portion 401 d of the receptacle body 401 is formed.

  On the outside of the end wall 22 of the metal cap 20, a metal fitting 24 for attaching a chain for connecting the metal cap to a case or a receptacle body of an electric device so as not to be lost is fixed. Further, as shown in FIG. 3, when the metal cap 20 is screwed to the receptacle body 401, the inner periphery of the opening end of the metal cap 20 and the receptacle are disposed on the inner periphery of the opening end of the peripheral wall portion 21 of the metal cap 20. An O-ring 25 that seals the connecting portion between the metal cap 20 and the receptacle body 401 is held between the peripheral wall portion that defines the inner peripheral portion of the groove portion 401 c of the body 401.

  In this embodiment, the insulation cap 12 of the short circuit 10 has a size that can be fitted to the inner periphery of the metal cap 20, and each short circuit contact of the short circuit 10 is provided as shown in FIG. The metal cap 20 is placed in the receptacle body as shown in FIG. 3 in a state in which the plug 4 is brought into contact with the corresponding contact of the receptacle 4 and the short-circuit insulating cap 12 is put on the insulating support 403 of the contact assembly 402. When screwed to 401, the insulating cap 12 of the short-circuiting element 10 is received in the metal cap 20 to insulate between the short-circuiting body 11 and the ground potential portion including the metal cap 20.

  With each short-circuit contact of the short-circuit 10 brought into contact with a corresponding contact of the receptacle 4 from which the plug has been removed, and with the insulating cap 12 of the short-circuit 10 placed on the insulating support 403 of the contact assembly 402, the metal cap 20 is screwed to the receptacle body 401, the air in the space between the bottom 12b of the insulating cap 12 and the end wall 22 of the metal cap 20 is compressed, and the pressure is compressed between the metal cap 20 and the receptacle body 401. In this embodiment, when the metal cap 20 is attached by forming the air vent groove 12d on the outer periphery of the short-circuit insulating cap 12, the bottom of the short-circuit insulating cap 12 Since the air in the space formed with the metal cap is discharged to the outside through the air vent groove 12d, The attachment of the cap 20 can be performed without any trouble.

  As in this embodiment, the insulating cap 12 is made of an insulating material having elasticity, and the flange plate of the short-circuit body 11 is placed in the short-circuit locking groove 12c formed on the inner periphery of the cylindrical portion 12a of the insulating cap. When the short-circuit main body 11 is held by the insulating cap 12 by fitting a portion near the outer periphery of the short-circuit, the assembly of the short-circuit 10 can be facilitated. Moreover, when comprised in this way, by hold | gripping and hold | maintaining the part near the bottom part 12b of the side wall part 12a of the insulation cap 12, without making the short circuit body main body 11 remove | separate from the insulation cap 12, the whole short circuit element 10 is obtained. Since it can hold | maintain, even if it does not provide an insulating knob in the short circuit 10, a short circuit can be attached or detached, and the structure of a short circuit can be simplified.

  In the above embodiment, the receptacle body 401 does not have a portion surrounding the head of the insulating support 403 of the contact assembly 402, but surrounds a part of the head of the insulating support 403 of the contact assembly 402. The present invention can also be applied when the peripheral wall portion is provided in the receptacle body 401. Also in this case, in a state where the short circuit 10 is connected to the receptacle 4, the portion near the bottom 12b of the insulating cap 12 of the short circuit 10 is disposed so as to protrude outward from the end face of the receptacle body 401. By setting the dimensions of the contact assembly 402 of the receptacle 4 and the dimensions of the short-circuit 10, at least a portion of the short-circuit 10 near the bottom 12 b of the insulating cap 12 in a state where the short-circuit 10 is connected to the receptacle 4. Can be arranged in a state of projecting outward from the end face of the receptacle body 401, so that the portion near the bottom of the insulating cap 12 of the short-circuit 10 is moved together with the short-circuit body 11 inside by hand or a tool. By grasping, the short-circuiting element 10 can be easily attached and detached. When the receptacle body is configured in this way, the portion surrounding the contact assembly 402 of the receptacle body and the metal cap 20 serve as a ground potential portion surrounding the short-circuit body, and this ground potential portion and the short-circuit body 11 is insulated by an insulating cap 12.

  In the above embodiment, the present invention is applied to the circuit breaker provided in the distribution system. However, the present invention is provided with a current transformer, and the secondary coil of the current transformer is connected to an external device through the receptacle. Can be widely applied to electrical equipment.

  In the above embodiment, the short-circuit is connected to the receptacle attached to the other end of the instrumentation cable, one end of which is connected to a current transformer provided in the electric device. However, as shown in FIG. When the receptacle 4 'for connecting the instrumentation cable is attached to the case of the electric device, a short-circuit can be connected to the receptacle 4' attached to the case of the electric device.

  In the above embodiment, the receptacle contact for connecting the short-circuit is female, and the short-circuit contact is male. However, the contact supported in the insulating support of the receptacle is male, and the short-circuit contact The contact may be female.

DESCRIPTION OF SYMBOLS 3 Case of electrical equipment 4 Receptacle 4a-4g Female contact 401 Receptacle body 401d Female thread part 402 Contact assembly 403 Insulation support 404a thru | or 404g Through-hole 10 Short circuit 11 Short circuit body 11a thru | or 11g Short circuit contact 12 Insulation cap 12a Peripheral wall part 12b Bottom part 12c Short-circuiting element locking groove part 13 Flange plate 20 Metal cap 21 Peripheral wall part 22 End part wall 23 Male thread part

Claims (7)

A plurality of contacts each including an electric device body housed in a case, a current transformer for measuring an alternating current flowing through the electric device body, and a contact for taking out an output of a secondary coil of the current transformer. A receptacle formed by supporting the insulating support of a contact assembly having a structure in which the outline of a cross-section is supported in a circular shape in a state where the axes are parallel to each other in a circular shape, on a receptacle body made of a conductive material, and the receptacle A metal cap screw-coupled to the body and covering the contact assembly of the receptacle, and a contact of a plug is connected to the contact of the receptacle in a state where the metal cap is removed, and the plug and the receptacle are passed through the plug and the receptacle. In electrical equipment where the output of the current transformer is supplied to external equipment,
A plurality of short-circuiting contacts, each of which is in contact with a plurality of contacts that need to be short-circuited to each other in the receptacle with the plug removed, are electrically connected to each other. A conductive short-circuit body having a connected structure; and an insulating cap having a bottomed cylindrical shape that covers an insulating support of the contact assembly and holding the short-circuit body inside. Provided with a short circuit,
Each short-circuit contact of the short-circuit is brought into contact with a corresponding contact of the receptacle from which the plug has been removed, and the metal cap is placed on the receptacle body in a state where the insulating cap is placed on an insulating support of the contact assembly. When the screw coupling is performed, an insulating cap of the short-circuit is received in the metal cap and is configured to insulate between the short-circuit body and a ground potential portion including the metal cap.
Electrical equipment with a current transformer characterized by The plurality of short-circuit contacts of the short-circuit body are integrated by electrically and mechanically connecting each rear end portion to a flange plate made of a conductive material,
The insulating cap is made of an insulating material having elasticity, and is positioned near the bottom of the cylindrical portion of the insulating cap, and a short-circuit locking groove is provided around the inner periphery of the cylindrical portion,
The short-circuit body is accommodated in the insulating cap, and the portion near the outer periphery of the flange plate is held in the insulating cap by being fitted into the short-circuiting engaging groove,
At least one air vent groove extending over the entire length of the cylindrical portion in the axial direction is formed on the outer periphery of the cylindrical portion of the insulating cap,
When the metal cap is screwed to the receptacle body of the receptacle to which the short-circuit is connected, formed between the bottom of the cylindrical portion of the short-circuit insulation cap received inside the metal cap and the metal cap Configured to be able to exhaust the air in the space to be discharged to the outside through the air vent groove,
An electric device comprising the current transformer according to claim 1.   The contact assembly of the receptacle is arranged such that a portion near the bottom portion of the cylindrical portion of the insulation cap of the short circuit protrudes outward from the end face of the receptacle body in a state where the short circuit is connected to the receptacle. The dimension of the above and the dimension of a short circuit are set, The electric equipment provided with the current transformer according to claim 2 characterized by things.   4. The current transformer according to claim 1, wherein the receptacle to which the short-circuiting element is connected is attached to the other end of an instrumentation cable having one end electrically connected to the secondary coil of the current transformer. With electrical equipment.   The electrical equipment provided with the current transformer according to claim 1, 2 or 3, wherein the receptacle to which the short-circuiting element is connected is attached to the case. A plurality of contacts each including an electric device body housed in a case, a current transformer for measuring an alternating current flowing through the electric device body, and a contact for taking out an output of a secondary coil of the current transformer. A receptacle formed by supporting the insulating support of a contact assembly having a structure in which the outline of a cross-section is supported in a circular shape in a state where the axes are parallel to each other in a circular shape, on a receptacle body made of a conductive material, and the receptacle A metal cap screw-coupled to the body and covering the contact assembly of the receptacle, and a contact of a plug is connected to the contact of the receptacle in a state where the metal cap is removed, and the plug and the receptacle are passed through the plug and the receptacle. A plug from the receptacle of an electrical device in which the output of the current transformer is supplied to an external device. A current transformer protective shorting terminal to be connected to the receptacle in place of the plug in order to protect the current transformer when is disconnected,
A plurality of short-circuiting contacts that respectively contact a plurality of contacts that need to be short-circuited to each other in the receptacle in a state where the plug is removed, and the plurality of short-circuiting contacts are electrically connected to each other. A metal short-circuit body having a structure,
An insulating cap having a bottomed cylindrical shape that covers an insulating support of the contact assembly of the receptacle and holding the short-circuit body inside;
Each short-circuit contact of the short-circuit body is brought into contact with a corresponding contact of the receptacle from which the plug has been removed, and the metal cap is placed in a state where the insulating cap is put on an exposed portion of the contact assembly. When the screw is connected to the receptacle body, the insulating cap is received in the metal cap and is configured to insulate between the short-circuit body and the metal cap.
A short circuit for current transformer protection. The plurality of short-circuit contacts of the short-circuit body are integrated by electrically and mechanically connecting each rear end portion to a flange plate made of a conductive material,
The insulating cap is made of an insulating material having elasticity, and is positioned near the bottom of the cylindrical portion of the insulating cap, and a short-circuit locking groove is provided around the inner periphery of the cylindrical portion,
The short-circuit body is accommodated in the insulating cap, and the portion near the outer periphery of the flange plate is held in the insulating cap by being fitted into the short-circuiting engaging groove,
At least one air vent groove extending over the entire length of the cylindrical portion in the axial direction is formed on the outer periphery of the cylindrical portion of the insulating cap,
When the metal cap is screwed to the receptacle body of the receptacle to which the short-circuit is connected, formed between the bottom of the cylindrical portion of the short-circuit insulation cap received inside the metal cap and the metal cap Configured to be able to exhaust the air in the space to be discharged to the outside through the air vent groove,
The short circuit protector for current transformer according to claim 6 characterized by things.

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