Test junction box with load adjustment metering transformation ratio

Abstract

The invention relates to a test junction box with a load adjustment metering transformation ratio, which comprises a box cover and a box body, and is characterized in that a plurality of voltage and current wiring areas are arranged in the box body, and a current wiring area is arranged between adjacent voltage wiring areas; the voltage wiring area comprises a first voltage wiring area, a second voltage wiring area and a third voltage wiring area, and the current wiring area comprises a first current wiring area and a second current wiring area; the input sides of the first voltage wiring area, the second voltage wiring area and the third voltage wiring area are Y-shaped input connecting blocks, and the output sides are two output connecting blocks; the mutual inductor sides of the first current wiring area and the second current wiring area are provided with concave and Y-shaped input connecting blocks, and the electric energy meter side is provided with two rectangular and one convex output connecting block, so that no loss of metering electric quantity is caused when metering transformation ratio wiring is adjusted without power cut, and metering accuracy is realized.

Description

Technical Field

[0001] The invention relates to a test junction box with load-adjustable metering ratio, belonging to the technical field of junction boxes. Background Art

[0002] The test junction box is an important part of the electric energy metering device. It is widely used between electric energy meters, collection terminals and transformers connected by transformers. When it is necessary to replace the electric energy meter, collection terminal or calibrate the electric energy meter without power outage, the replacement of the electric energy meter, collection terminal or calibration of the electric energy meter can be achieved by changing the voltage and current connection pieces in the test junction box.

[0003] As an important instrument for measuring current, the current transformer must ensure that the output current value of the transformer is within the reasonable measurement range of the electric energy meter during current measurement. If the output current exceeds or is far below the reasonable measurement range of the electric energy meter, it will cause a large measurement error and cannot meet the requirements of electric energy metering accuracy.

[0004] There are at least the following disadvantages in the use of existing joint junction boxes:

[0005] 1. At present, the power load of some domestic customers or regions is unstable and fluctuates greatly. For example, some enterprises need to adjust their production load as the market changes, and the power load in rural areas changes significantly with the seasons, which reduces the timeliness and accuracy of distribution network line operation monitoring. At this time, the current transformer needs to be replaced. The conventional replacement method requires power outage, which will bring inconvenience to customers and even increase the cost of power outage.

[0006] 2. Some users choose to configure multi-tap current transformers with metering windings at their metering points to solve the above problems. However, there is no test junction box for multi-tap current transformers with metering windings on the market. Adjusting the transformation ratio of the above current transformers on conventional terminal blocks or test junction boxes is not only time-consuming and difficult to identify, but also easily leads to false connections or ratio adjustment errors.

[0007] 3. Traditional test junction boxes can only use the same junction box but connect one point in parallel in the voltage circuit, and the electric energy meter and the load control terminal current circuit in series. As a result, when the electric energy meter or load control terminal is replaced, the power cannot be measured normally, and the measurement can only be restored after the replacement is completed, resulting in under-measurement of power.

[0008] 4. The voltage and current connectors of traditional test junction boxes are prone to wiring errors and safety risks. Due to skill level or negligence, operators fail to adjust the connectors into place or fail to restore the connectors to their initial state, resulting in errors in the metering wiring circuit and inaccurate measurement. The specific traditional junction box has the same upper and lower wiring ports, generally using a 3-in 3-out method. The operating procedures require ports 2 and 3 at the lower end to be used as inputs and ports 1 and 3 at the upper end to be used as outputs. In actual operation, operators make wiring errors due to negligence and connect the upper and lower ends to ports 2 and 3, which will make it impossible to perform current connector on-off operations in other subsequent operations, causing the junction box to lose its proper function.

[0009] 5. Two screwdrivers are needed to adjust the connector of the traditional test junction box. When adjusting, the screwdrivers are likely to touch other live terminals, resulting in an open circuit or short circuit, which poses a high safety risk. It is difficult for operators to operate with two screwdrivers in a switch cabinet or meter box with a small space.

[0010] 6. The on-site calibration and replacement of traditional test junction boxes require many and cumbersome steps. The voltage and current connecting pieces require more than four steps from disconnection to closing (or closing to disconnection), which affects work efficiency.

[0011] For example, patent CN115528618A discloses a junction box for adjusting the metering ratio without power outage. The patent sets multiple partitions, connects multiple secondary wirings with multiple ratios on the current secondary circuit transformer side, and a single output line on the output side. The existing patent cannot realize on-site electric energy meter calibration operation; at the same time, when replacing the electric energy meter, if the operator does not determine the correct connection method of the short-circuit corresponding to the terminal connected to the current transformer side, it is easy to cause the short-circuit to slip open by mistake, causing the current transformer secondary circuit to open. Summary of the invention

[0012] In order to solve the above problems existing in the prior art, the present invention provides a test junction box with load adjustment of metering ratio, which can achieve no loss in metering electricity when adjusting the metering ratio wiring without power outage, thereby achieving metering accuracy.

[0013] The technical solution of the present invention is as follows:

[0014] A test junction box with load-adjustable metering ratio, comprising a box cover and a box body, wherein the box body comprises a plurality of voltage connection areas, and adjacent voltage connection areas are provided with current connection areas, and each connection area is separated by an insulating partition; the voltage connection area and the current connection area are embedded in the box body; the voltage connection area comprises: a first voltage connection area, a second voltage connection area and a third voltage connection area, and the current connection area comprises: a first current connection area and a second current connection area; the structure is only a three-phase three-wire connection mode, and a three-phase four-wire connection mode adds a voltage connection area and a current connection area accordingly;

[0015] The voltage connection area is provided with one incoming wire hole on the transformer side, and two outgoing wire holes on the electric energy meter side; the current connection area is provided with more than three incoming wire holes on the transformer side, and four outgoing wire holes on the electric energy meter side.

[0016] Preferably, the box cover is provided with two L-shaped buckles, two screw through holes, a limit block, and markings on the electric energy meter side and the transformer side. The box body is provided with an L-shaped slot and a box cover screw hole; the first voltage wiring area is provided with a voltage output connection block, an output fastening screw hole, a test wiring hole, a voltage connection piece, a connection piece screw, a connection piece limit block, a Y-shaped input connection block, and an input fastening screw hole. The first current wiring area is provided with a Y-shaped input connection block, an input fastening screw hole, a current connection piece, a connection piece screw, a rectangular / convex current output connection block, an output fastening screw hole, a test wiring hole, a current shorting piece, a shorting piece screw, a shorting piece limit block, a connection piece limit block, a rectangular / concave input connection block, and a connection piece storage slot; the other voltage and current wiring areas have the same structure as the first voltage and current wiring area. The first voltage wiring area, the first current wiring area, the second voltage wiring area, the second current wiring area, and the second voltage wiring area are arranged in sequence from left to right. The box body is also provided with a plurality of insulating partitions, and the insulating partitions are provided between adjacent voltage wiring areas and current wiring areas.

[0017] Preferably, an L-shaped slot is provided on one side edge of the box body, and an L-shaped buckle protrusion is correspondingly provided on the inner side of the box cover, and the L-shaped protrusion cooperates with the slot to achieve a tight fit to ensure that the mark on the electric energy meter side of the box cover is on the top and the mark on the transformer side is on the bottom; screw through holes are respectively provided on both sides of the box cover and the box body and correspond one to one so as to be fixedly connected by lead sealing screws.

[0018] Preferably, the voltage connecting piece includes a screw, a locking part, and a short-circuit part; the locking part fixes the short-circuit part in the middle of the screw, and the screw is locked into the screw hole of the base, so that the connecting piece can be short-circuited with the voltage output connection block and the Y-shaped voltage input connection block. The test wiring hole is directly connected to the voltage and current output connection block, the Y-shaped input connection block, and the concave input connection block. The inner side of the lower end of the jack is funnel-shaped and the inner wall has textures, so that the test line is inserted more firmly and is not easy to fall off.

[0019] Preferably, the voltage output connection block and the Y-shaped input connection block of the first voltage wiring area are provided with wire jacks on the sides of the input ends, and double screw through holes are provided on the upper ends to fix the input and output wires. The rectangular current input / output connection block and the Y-shaped input connection block of the first current wiring area have the same structure as the voltage wiring block. All kinds of voltage and current connection blocks are embedded in the box body. The wire fixing structure and module embedded structure of the other voltage and current wiring areas are the same as those of the first voltage and current wiring area.

[0020] Preferably, the voltage output connection block and the Y-shaped input connection block of the first voltage wiring area are L-shaped platforms near the voltage connection piece end, and the voltage output connection block and the Y-shaped input connection block are electrically connected after the connection piece screws are tightened. The rectangular current input / output connection block, the concave input connection block and the Y-shaped input connection block of the first current wiring area are L-shaped platforms near the current connection piece end, and the current input and output connection blocks and the Y-shaped input connection block are electrically connected after the connection piece screws are tightened. The limit block is a protruding column on the inner side of the box cover, which is used to just against the lower end of the column when the connection piece or the short-circuit piece is fully locked. The voltage connection piece and the current connection piece have different colors. Used to distinguish between voltage and current wiring areas.

[0021] Preferably, the current shorting piece in the current wiring area is provided with a raised conductive end in the middle of the upper side and raised conductive ends on both sides of the lower side, so as to realize the cross connection between the current output connection block and the concave or Y-shaped input connection block. The current shorting piece screw through holes of the box body base are provided with three. When the shorting piece screw is locked in the shorting hole, the current output connection block and the concave or Y-shaped input connection block can be electrically connected. When the shorting piece screw is locked in the storage slot, the above electrical connection is disconnected. When the current shorting piece screw is unscrewed, it can be slid left and right to adjust the connection mode.

[0022] Preferably, the Y-shaped input connection block, voltage output connection block, rectangular / concave input connection block, rectangular / convex current output connection block, voltage / current connection piece, current shorting piece, and test wiring hole are made of copper-zinc alloy or galvanized iron alloy. The box body is made of transparent high-molecular polycarbonate, and the box cover is made of transparent ABS plastic.

[0023] The present invention has the following beneficial effects:

[0024] The test junction box for load-adjustable ratio of multi-tap current transformer with metering winding of the present invention can quickly adjust the secondary circuit wiring on the transformer side of the junction box, change the wiring mode, and realize the current transformer ratio adjustment to meet the requirements of electric energy metering according to the transmission and distribution line or the actual operating load of the user. The current transformer ratio adjustment test junction box has the advantages of convenience, safety, reliability, cost saving, etc., and completes the transformer ratio adjustment without power outage, which has a significant effect on improving the comprehensive benefits of power supply enterprises.

[0025] In the present invention, the test wiring hole of the junction box is directly connected to the current output connection block and the concave / Y-shaped input connection block, so the test line of the electric energy meter calibrator can be directly plugged into the test wiring hole through the banana head to realize the voltage parallel connection and current series connection functions, which greatly improves the efficiency of on-site calibration without the need to use traditional operation methods. At the same time, the voltage / current short circuit or disconnection is achieved by rotating the connecting piece screw, which can be achieved with only a screwdriver. The operation is simple, convenient and safe, eliminating the traditional cumbersome operation of disconnecting the connecting piece, and improving the convenience and safety of the operation.

[0026] In the present invention, in order to solve the problem of easy wiring errors in traditional junction boxes, a limit block is provided to determine whether the device in the junction box has recovered to a normal metering state. At the same time, the up and down directions are marked on the junction box and the box cover to prevent wiring errors and inverted installation of the junction box.

[0027] In the present invention, the size and installation hole of the junction box are similar to those of the traditional junction box, which is convenient for on-site installation. At the same time, considering safety, spring components and active electronic devices are not used to solve other problems of the traditional junction box.

[0028] In the present invention, there are at least two wiring jacks at the voltage output end and at least four wiring jacks at the current output end, which can meet the simultaneous access of two electric energy meters or an electric energy meter and a load control terminal. Through the voltage and current connecting pieces and the current shorting piece, the user's power consumption can be seamlessly measured when the electric energy meter is replaced without losing the electric energy metering data. There is one wiring jack at the voltage input end and at least three wiring jacks at the current input end to meet the access of the multi-ratio current transformer loop.

[0029] In the present invention, an insulating partition is arranged inside the junction box body to separate different wiring areas, so that different phases can be clearly identified during operation, and the arc generated during a fault can be blocked to avoid phase-to-phase short circuits caused by circuits or by operator operation, thereby further expanding the scope of losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the box cover structure of the present invention;

[0031] Figure 2 It is a schematic diagram of the overall structure of a test junction box with load-adjustable metering ratio according to the present invention;

[0032] Figure 3 is a side sectional view of a test junction box of the present invention;

[0033] Figure 4 It is a schematic diagram of the shorting piece structure of the present invention;

[0034] Figure 5 It is a schematic diagram of the connecting piece structure of the present invention;

[0035] Figure 6It is a combined diagram of a Y-shaped voltage input connection block, a connection piece, and a voltage output connection block of the present invention;

[0036] Figure 7 It is a structural combination diagram of a rectangular current input connection block and the like of the present invention;

[0037] Figure 8 It is a structural combination diagram of the Y-shaped current input connection block and the like of the present invention;

[0038] Fig. 9 It is a schematic diagram of the operation or replacement terminal of a single electric energy meter of the present invention.

[0039] Fig.10 It is intended to represent the replacement of electrical energy of the present invention.

[0040] Fig.11 It is a schematic diagram of the test junction box of the present invention before and after the transformation ratio is adjusted.

[0041] Fig.12 The present invention provides a test junction box, an electric energy meter, a load control terminal and a secondary circuit wiring diagram.

[0042] The reference numerals in the figure are as follows:

[0043] 1. Box cover; 2. L-shaped buckle; 3. Screw hole; 4. First voltage connection area; 5. Voltage output connection block; 6. L-shaped slot; 7. Output fastening screw hole; 8. Connection piece limit block; 9. Box cover screw hole; 10. Voltage connection piece; 11. First connection piece screw; 12. Test connection hole; 13. Y-shaped voltage input connection block; 14. Input fastening screw hole; 15. Rectangular current input connection block; 16. Connection piece storage slot; 17. First current connection area; 18. Y-shaped current input connection block; 19. Insulating partition; 20. Second voltage connection area; 21. Second current connection area; 22. Third voltage connection area; 23. Box body; 24. Shorting piece fixing hole; 25. Current connecting piece; 26. Shorting piece limit block; 27. Concave current input connection block; 28. Current shorting piece; 29. ​​Convex current output connection block; 30. Rectangular current output connection block; 31. Box body base; 32. Output fastening screw; 33. Input fastening screw; 34. Wiring jack; 35. Shorting piece screw; 36. First fastening part; 37. Shorting piece shorting part; 38. Second connecting piece screw; 39. Connecting piece shorting part; 40. Second fastening part; 42. L-shaped platform; 43. Limit block. DETAILED DESCRIPTION

[0044] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] See also Figures 1 to 12 , the invention provides a technical solution:

[0046] A test junction box with load-adjustable metering ratio, comprising a box cover 1 and a box body 23;

[0047] The box cover 1 includes: an L-shaped buckle 2, a screw through hole 3, a limit block 43, and a mark on the side of the electric energy meter and the side of the transformer. The mark on the side of the electric energy meter and the side of the transformer can prevent wiring errors and inverted installation of the junction box; the box body 23 includes: an L-shaped slot 6, a box cover screw hole 9, a module fixing slot 16, a box body base 31, and a wiring jack 34; in this embodiment, L-shaped slots 6 are respectively arranged on the upper and lower edges of one side of the box body 23, and an L-shaped buckle 2 is arranged on the inner side of the box cover 1. The L-shaped buckle 2 is embedded in the L-shaped slot 6 to realize the buckling of the box cover 1 and the box body 23, so as to ensure that the mark on the side of the electric energy meter on the outside of the box cover 1 is on the top, and the mark on the side of the transformer is on the bottom; screw through holes 3 and box cover screw holes 9 are respectively arranged on both sides of the box cover 1 and the box body 23 and correspond to each other, so as to pass the lead sealing screws to fix the box cover 1 and the box body 23.

[0048] The box body 23 is provided with a first voltage connection area 4, a second voltage connection area 20 and a third voltage connection area 22, a first current connection area 17 and a second current connection area 21; the first voltage connection area 4, the first current connection area 17, the second voltage connection area 20, the second current connection area 21, and the second voltage connection area 22 are arranged in sequence from left to right. The structure is only a three-phase three-wire connection mode, and a voltage and current connection area is added for each of the three-phase four-wires; the first voltage connection area 4, the second voltage connection area 20 and the third voltage connection area 22 are provided with an inlet hole on the transformer side, and two outlet holes on the electric energy meter side; the first current connection area 17 and the second current connection area 21 are provided with more than three inlet holes on the transformer side, and four outlet holes on the electric energy meter side.

[0049] The first voltage wiring area 4 includes: a voltage output connection block 5, an output fastening hole screw 22, a connection piece limit block 8, a voltage connection piece 10, a first connection piece screw 11, a test wiring hole 12, a Y-shaped voltage input connection block 13, and an input fastening screw hole 14; the second voltage wiring area 20 and the third voltage wiring area 22 have the same structure as the first voltage wiring area 20;

[0050] The first current wiring area 17 includes: a rectangular current input connection block 15, a connection piece storage slot 16, a Y-shaped current input connection block 18, a shorting piece fixing hole 24, a current connection piece 25, a shorting piece limit block 26, a concave current input connection block 27, a current shorting piece 28, a convex current output connection block 29, and a rectangular current output connection block 30. The second current wiring area 21 has the same structure as the first current wiring area 17.

[0051] The box body further comprises a plurality of insulating partitions 19 , and insulating partitions 19 are arranged between adjacent areas of the first voltage connection area 4 , the first current connection area 17 , the second voltage connection area 20 , the second current connection area 21 and the third voltage connection area 22 .

[0052] The first voltage connection area 4 is provided with one connection socket 34 on the transformer side, and two connection sockets 34 on the electric energy meter side; the first current connection area 17 is provided with at least three connection sockets 34 on the transformer side, and four connection sockets 34 on the electric energy meter side. In this embodiment, the voltage output connection block 5, the Y-shaped current input connection block 18, the Y-shaped voltage input connection block 13, the rectangular current input connection block 15, the concave current input connection block 27, the rectangular current output connection block 30, and the convex current output connection block 29 are provided with double fastening screw structures at the corresponding connection sockets 34 to fix the input and output wiring, and the voltage output connection block 5, the Y-shaped current input connection block 18, the Y-shaped voltage input connection block 13, the rectangular current input connection block 15, the concave current input connection block 27, the rectangular current output connection block 30, and the convex current output connection block 29 are fixed in the box body 23 of the insulating material by mold casting.

[0053] The inner side of the box cover 1 is provided with a limit block 43 corresponding to the voltage connecting piece 10, the current connecting piece 25, and the current shorting piece 28. The limit block 43 is a columnar structure protruding from the inner side of the box cover 1. When the first connecting piece screw 11, the second connecting piece screw 38, and the shorting piece screw 35 are fully tightened, they just abut against the lower end of the limit block 43. The voltage connecting piece 10, the current connecting piece 25, and the current shorting piece 28 are configured with different colors according to different phases.

[0054] In this embodiment, the voltage connecting piece 10 and the current connecting piece 25 have the same structure but different sizes, and both include: a second connecting piece screw 38, a first fastening portion 36, a connecting piece short-circuit portion 39, and a second fastening portion 40; the upper and lower ends of the connecting piece short-circuit portion 39 are respectively provided with the first fastening portion 36 and the second fastening portion 40, and the first fastening portion 36 and the second fastening portion 40 are used to fix the connecting piece short-circuit portion 39 in the middle position of the second connecting piece screw 38; the current shorting piece 28 includes a shorting piece screw 35 and a shorting piece shorting portion 37, and the upper and lower ends of the shorting piece shorting portion 37 are also respectively provided with the first fastening portion 36 and the second fastening portion 40, and the first fastening portion 36 and the second fastening portion 40 are used to fix the shorting piece shorting portion 37 in the middle position of the shorting piece screw 35.

[0055] The voltage output connection block 5 and the Y-shaped voltage input connection block 13 of the first voltage connection area 4 are L-shaped platforms 42 near the voltage connection piece 10, and the voltage output connection block 5 and the Y-shaped voltage input connection block 13 are electrically connected after the first connection piece screw 11 is tightened. The rectangular current input connection block 15, the rectangular current output connection block 30, the concave current input connection block 27 and the Y-shaped current input connection block 18 of the first current connection area 17 are L-shaped platforms 42 near the current connection piece 25, and threads matching the second connection piece screw 38 are provided at the upper end of the L-shaped platform 42 of the Y-shaped voltage input connection block 13, the Y-shaped current input connection block 18, the rectangular current input connection block 15 and the concave current input connection block 27, so that the voltage connection piece 10 and the current connection piece 25 can be tightly connected with the Y-shaped voltage input connection block 13, the Y-shaped current input connection block 18, the rectangular current input connection block 15 and the concave current input connection block 27.

[0056] The voltage output connection block 5 of the first voltage connection area 4 and the input end of the Y-shaped voltage input connection block 13 are provided with wire jacks on their sides, and double screw through holes are provided on their upper ends for fixing the input and output wires.

[0057] The test wiring hole 12 is directly welded to the voltage output connection block 5, the rectangular current input connection block 15, the rectangular current output connection block 30 and the Y-shaped current input connection block 18 to form an electrical connection. The inner side of the lower end of the test wiring hole 12 is funnel-shaped and the inner wall has textures, which increases the friction after the banana head is inserted, making the test line more firmly inserted and not easy to fall off.

[0058] In this embodiment, the current shorting piece 28 in the first current wiring area 17 is provided with a raised conductive end in the middle position of the upper side, and two raised conductive ends protrude from both sides of the lower side, so as to realize the connection between the rectangular current output connection block 30, the convex current output connection block 29, the concave current input connection block 27, and the Y-shaped current input connection block 18 in pairs.

[0059] The current shorting piece 28 of the box base 31 has three screw through holes. When the shorting piece screw 35 is locked in the shorting hole, the rectangular current output connection block 30, the convex current output connection block 29, the concave current input connection block 27 or the Y-shaped current input connection block 18 can be electrically connected. When the shorting piece screw 35 is locked in the storage slot, the above electrical connection is disconnected. When the current short-circuit screw 35 is unscrewed, it can slide left and right to adjust the connection mode; the box base 31 is provided with three short-circuit fixing holes 24. When the current short-circuit screw 35 is locked in the short-circuit fixing hole 24 on the left, the Y-shaped current input connection block 18, the Y-shaped current input connection block 15, the concave current input connection block 27, the rectangular current output connection block 30, and the convex current output connection block 29 are not electrically connected; when locked in the middle short-circuit fixing hole 24, the concave current input connection block 27 and the convex current output connection block 29 are electrically connected; when locked in the short-circuit fixing hole 24 on the right, the Y-shaped current input connection block 18 and the convex current output connection block 29 are electrically connected.

[0060] In this embodiment, the Y-shaped voltage input connection block 13, the voltage output connection block 5, the Y-shaped current input connection block 18, the rectangular current input connection block 15, the concave current input connection block 27, the rectangular current output connection block 30, the convex current output connection block 29, the voltage connection piece 10, the current connection piece 25, the current shorting piece 28, and the test wiring hole 12 are all made of copper-zinc alloy or galvanized iron alloy.

[0061] In this embodiment, the box body 23 is made of green high molecular weight polycarbonate, and the box cover 1 is made of transparent ABS plastic.

[0062] More specific instructions for using the junction box: During normal operation, if Figure 6 The structure diagram shown is when a single electric energy meter on the left is in operation or the negative control terminal (electric energy meter) on the right is replaced. The voltage connecting piece 10 on the left is locked to realize the electrical connection between the Y-shaped voltage input connecting block 13 and the voltage output connecting block 5 on the left, and the right side is placed in the connecting piece storage slot 16; the current shorting piece 28 is locked in the right shorting piece fixing hole 24 to realize the electrical connection between the convex current output connecting block 29 and the Y-shaped current input connecting block 18; only the left current connecting piece 25 is connected between the rectangular current input connecting block 15 and the concave current input connecting block 27, and the right current connecting piece 25 is placed in the connecting piece storage slot 16; the current connecting piece 25 between the concave current input connecting block 27, the Y-shaped current input connecting block 18 and the rectangular current output connecting block 30 is locked. At this time, the single electric energy meter on the left is in operation or preparations are made to replace the negative control terminal (electric energy meter) on the right.

[0063] like Figure 7The diagram shows the structure of a single electric energy meter on the right side when it is running or when the negative control terminal on the left side is replaced. The voltage connecting piece 10 on the right side is locked to realize the electrical connection between the voltage output connecting block 5 on the right side and the Y-shaped voltage input connecting block 13, and the left side is placed in the connecting piece storage slot 16; the current shorting piece 28 is locked in the middle shorting piece fixing hole 24 to realize the electrical connection between the convex current output connecting block 29 and the concave current input connecting block 27; only the left current connecting piece 25 is connected between the rectangular current input connecting block 15 and the concave current input connecting block 27, and the right current connecting piece 25 is placed in the connecting piece storage slot 16; the current connecting piece 25 is locked between the concave current input connecting block 27, the Y-shaped current input connecting block 18 and the rectangular current output connecting block 30. At this time, the single electric energy meter on the right side is running or preparations are made to replace the negative control terminal (electric energy meter) on the left side.

[0064] like Figure 8 The diagram shows a schematic diagram of the structure for adjusting the transformation ratio when a single electric energy meter on the left is in operation. The current connecting pieces 25 on the left and right are first connected between the rectangular current input connection block 15 and the concave current input connection block 27, and then the current connecting piece 25 on the left is contacted and placed in the connecting piece storage slot 16. The original S1-S3 access mode is adjusted to S2-S3 to achieve transformation ratio adjustment.

[0065] Fig. 9 This is a wiring diagram of a test junction box, an electric energy meter, a load control terminal and a secondary circuit in one embodiment of the present application.

[0066] The A-phase voltage of the secondary circuit of the voltage transformer is input from the Y-shaped voltage input connection block 13 of the first voltage connection area, and is electrically connected to the voltage output connection block 5 through the voltage connection piece 10; so that the secondary voltage of the voltage transformer is input from the voltage output connection block 5 to the electric energy meter and the negative control terminal, so that the electric energy meter and the negative control terminal are connected to the voltage secondary circuit. The A-phase current of the secondary circuit of the current transformer is input from the first current connection area 17, the polarity end is connected to the rectangular current input connection block 15, and is electrically connected to the concave current input connection block 27 through the current connection piece 25, and then the concave current input connection block 27 is electrically connected to the rectangular current output connection block 30 through the current connection piece 25. The non-polarity end is connected to the Y-shaped current input connection block 18, and is electrically connected to the rectangular current output connection block 30 and the convex current output connection block 29 through the current connection piece 25. The current transformer current flows through the rectangular current input connection block 15, the current connection piece 25, the concave current input connection block 27, the electric energy meter, the convex current output connection block 29, the negative control terminal, and finally flows out from the rectangular current output connection block 30, the convex current output connection block 29, the current connection piece 25, and the Y-shaped current input connection block 18. The electric energy meter, the negative control terminal and the current transformer current secondary circuit are connected in series.

[0067] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A test junction box with load-adjustable metering ratio, comprising a box cover (1) and a box body (23), characterized in that: The box body (23) is provided with a first voltage connection area (4), a first current connection area (17), a second voltage connection area (20), a second current connection area (21) and a third voltage connection area (22) in sequence from left to right; the structures in the first voltage connection area (4), the second voltage connection area (20) and the third voltage connection area (22) are the same, and the structures in the first current connection area (17) and the second current connection area (21) are the same; the input sides of the first voltage connection area (4), the second voltage connection area (20) and the third voltage connection area (22) are all provided with a Y-shaped A voltage input connection block (13); two voltage output connection blocks (5) are provided on the output sides of the first voltage connection area (4), the second voltage connection area (20) and the third voltage connection area (22); a rectangular current input connection block (15), a concave current input connection block (27) and a Y-shaped current input connection block (18) are provided on the transformer side of the first current connection area (17) and the second current connection area (21); two rectangular current output connection blocks (30) and a convex current output connection block (29) are provided on the electric energy meter side of the first current connection area (17) and the second current connection area (21).

2. A test junction box with load-adjustable metering ratio as claimed in claim 1, characterized in that: The first voltage connection area (4), the second voltage connection area (20) and the third voltage connection area (22) are all distributed on the top of the box body base (31) of the box body (23); and voltage connection pieces (10) are provided between the two ports of the two voltage output connection blocks (5) and the Y-shaped voltage input connection block (13).

3. A test junction box with load-adjustable metering ratio as claimed in claim 2, characterized in that: The second current connection area (21) and the first current connection area (17) are both distributed on the top of the box body base (31) of the box body (23); current connection pieces (25) are provided between one of the rectangular current output connection blocks (30) and the concave current input connection block (27), between another rectangular current output connection block (30) and the Y-shaped current input connection block (18), and between the rectangular current input connection block (15) and the concave current input connection block (27) in the same area. The box body base (31) is provided with three short-circuit fixing holes (24) in the area corresponding to the second current wiring area (21) and the first current wiring area (17); it also includes a current short-circuit (28) and a short-circuit screw (35), and electrical connection is achieved by switching the current short-circuit (28) and the short-circuit screw (35) to lock the position of the short-circuit fixing hole (24), and the second current wiring area (21) and the first current wiring area (17) are provided with a connecting piece storage groove (16).

4. A test junction box with load-adjustable metering ratio as claimed in claim 1, characterized in that: The box cover (1) comprises an L-shaped buckle (2) and a screw through hole (3); L-shaped slots 6 are provided at both ends of the box body (23) to cooperate with the L-shaped buckle (2) to achieve a tight fit; box cover screw holes (9) are also provided at both ends of the box body (23) to match the screw through hole (3); the box body (23) further comprises a plurality of insulating partitions (19); insulating partitions (19) are provided between adjacent areas of the first voltage connection area (4), the first current connection area (17), the second voltage connection area (20), the second current connection area (21) and the third voltage connection area (22).

5. A test junction box with load-adjustable metering ratio as claimed in claim 2, characterized in that: The current connecting piece (25) and the voltage connecting piece (10) have the same structure. Both the voltage connecting piece (10) and the current connecting piece (25) include a second connecting piece screw (38) and a connecting piece short-circuit portion (39). The upper and lower ends of the connecting piece short-circuit portion (39) are respectively provided with a first fastening portion (36) and a second fastening portion (40). The first fastening portion (36) and the second fastening portion (40) are used to fix the connecting piece short-circuit portion (39) at a middle position of the second connecting piece screw (38). The current shorting piece (28) includes a shorting piece screw (35) and a shorting piece short-circuit portion (37). The upper and lower ends of the shorting piece short-circuit portion (37) are respectively provided with a first fastening portion (36) and a second fastening portion (40). The first fastening portion (36) and the second fastening portion (40) are used to fix the shorting piece short-circuit portion (37) at a middle position of the shorting piece screw (35).

6. A test junction box with load-adjustable metering ratio as claimed in claim 3, characterized in that: The first voltage wiring area (4), the first current wiring area (17), the second voltage wiring area (20), the second current wiring area (21), and the third voltage wiring area (22) are all provided with test wiring holes (12), and the test wiring holes (12) are connected to a Y-shaped voltage input connection block (13), a voltage output connection block (5), a concave current input connection block (27), a Y-shaped current input connection block (18), a rectangular current output connection block (30), and a convex current output connection block (29).

7. A test junction box with load-adjustable metering ratio as claimed in claim 2, characterized in that: The voltage output connection block (5) and the Y-shaped voltage input connection block (13) of the first voltage connection area (4) are close to one end of the voltage connection piece (10), and the rectangular current output connection block (30), the convex current output connection block (29), the concave current input connection block (27) and the Y-shaped current input connection block (18) of the first current connection area (17) are all L-shaped platforms (42); electrical connection within the area is achieved on the L-shaped platform (42) by tightening the first connection piece screw (11).

8. A test junction box with load-adjustable metering ratio as claimed in claim 3, characterized in that: The current shorting piece (28) is provided with raised conductive ends in the middle of the upper side and on both sides of the lower side, and the raised conductive ends are used to realize cross-connection between the rectangular current output connection block (30), the convex current output connection block (29), the concave current input connection block (27), and the Y-shaped current input connection block (18).

9. A test junction box with load-adjustable metering ratio as claimed in claim 6, characterized in that: The voltage output connection block (5), the Y-shaped current input connection block (18), the Y-shaped voltage input connection block (13), the rectangular current input connection block (15), the concave current input connection block (27), the rectangular current output connection block (30), the convex current output connection block (29), the voltage connection piece (10), the current connection piece (25), the current shorting piece (28), and the test wiring hole (12) are all made of copper-zinc alloy or galvanized iron alloy; and the thickness and width of the Y-shaped current input connection block (18), the Y-shaped voltage input connection block (13), the rectangular current input connection block (15), the concave current input connection block (27), the rectangular current output connection block (30), and the convex current output connection block (29) are all 5 mm to 7 mm, and the thickness of the current connection piece (25) and the current shorting piece (28) are both above 3 mm.

10. A test junction box with load-adjustable metering ratio as claimed in claim 1, characterized in that: The box body (23) is made of a transparent high-molecular polycarbonate material, and the box cover (1) is made of a transparent ABS plastic material.

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