CN206878459U - A kind of electric-power metering comprehensive protection device - Google Patents

Abstract

The utility model discloses a comprehensive protector for power metering, which comprises a protective shell, a protector warning circuit and a surge overvoltage equipotential processing circuit connected between a power supply phase line and a neutral line. The surge overvoltage equipotential processing circuits are all located in the protective shell, and the surge overvoltage equipotential processing circuits include three varistors connected in parallel and a gas discharge device connected in series between the varistors and the ground wire. Tube. The utility model realizes the protection problem of the power metering device of the rural power grid by adopting the equipotential surge protection technology. The utility model does not depend on the grounding resistance, has strong protection ability, low residual voltage, and has high practical value.

Description

A comprehensive protector for power metering

technical field

The utility model relates to electric power protection equipment, in particular to a comprehensive protector for electric power measurement.

Background technique

Power lines cover every household in urban and rural areas. Power meters are indispensable power equipment for every household. However, their installation conditions are limited. Most of them are installed in the metering boxes on the walls of rural households. Under the eaves, on the wall, on the pole, etc. Without good lightning protection grounding and shielding protection, the power supply lines mostly take power from the nearest location, and are directly connected to the user's power meter box from nearby utility poles. Since the 0.4KV power cable is led out from the transformer room, it is directly overhead to the entrances of various streets or alleys in the village. There is no flash wire at the upper end of the overhead cable, and there is no grounding measure for each pole. Therefore, in the thunderstorm season every year, a large number of power meters and meter reading equipment or farmers' household appliances will be damaged by lightning strikes, which will cause power outages for farmers, loss of meter reading data, and increase maintenance costs. Therefore, the power meter box is in urgent need of lightning protection. However, because the power meter boxes of the rural power grid are located in front of and behind the house, and the ground is hardened and other reasons, it is not possible to make a large-scale ground network. The most difficult thing is that the grounding requires a resistance value of 4 ohms to prevent waves. The surge effect can be more obvious, so there is an urgent need for a power metering integrated protector that does not depend on grounding resistance, which can solve the above problems.

Utility model content

In order to solve the above problems, the utility model proposes a comprehensive protector for power metering. The utility model realizes the protection problem of the rural power metering device by adopting the equipotential surge protection technology. The utility model does not depend on the grounding resistance. Strong protection ability, low residual pressure, and high practical value.

In order to achieve the above object, the utility model adopts the following technical solutions:

A comprehensive protector for power metering, comprising a protective shell, a protector warning circuit and a surge overvoltage equipotential processing circuit connected between a power supply phase line and a neutral line, the protector warning circuit and a surge overvoltage equipotential The processing circuits are all located in the protective shell, and the surge overvoltage equipotential processing circuit includes three varistors connected in parallel and a gas discharge tube connected in series between the varistors and the ground wire. The role of the discharge tube is to avoid leakage current problems.

As a preferred solution, the utility model is not connected to the ground wire, and at the same time, no gas discharge tube is added, and the effect of voltage equalization can be realized only by the piezoresistor.

Further, both sides of the gas discharge tube are connected in parallel with overcurrent protection resistors.

Further, there are three phase wires of the power supply, namely L1, L2, and L3, and the three varistors are respectively RV1, RV2, and RV3, and each varistor is correspondingly connected to a phase wire of the power supply, that is, L1 , L2, and L3 are respectively connected to the RV1, RV2, and RV3. When the surge is generated, the surge enters the power interface of the arrester along the wire, that is, the phase line or neutral line of the power supply, and the instant between the phase line of the power supply and the neutral line of the power supply. When the pressure difference rises, the varistor is turned on at this time, reducing the instantaneous pressure difference to zero, thereby realizing full protection between the phase line and the neutral line, and between the phase line and the ground line.

Further, the protector warning circuit includes a warning light, a current limiting resistor and a thermal tripping device, the warning light is connected to the phase line of the power supply, one end of the thermal tripping device is connected to the current limiting resistor, and the other end is connected to the zero point of the power supply. line connection.

Further, there are three thermal tripping devices, and one thermal tripping device is pasted on each of the three piezoresistors.

Further, the protective shell is an aluminum alloy protective shell, and a transparent window is provided on the protective shell, and the warning light is located directly below the transparent window.

Further, a plurality of cooling holes are provided on the side wall of the protective housing, and the cooling holes are louver cooling holes, which can facilitate the heat dissipation of the comprehensive protector for electric power metering while preventing dust.

Further, the top of the protective shell is also provided with a wiring port, and the three phase wires of the power supply are connected to the piezoresistors inside the protective shell through the wiring ports.

Further, the protective shell is bolted to one side of the main power switch in the meter box.

Further, the maximum current carrying capacity of the surge overvoltage equipotential processing circuit is 100KA.

Compared with the prior art, the beneficial effects of the utility model are:

(1) The utility model overcomes the difficult problem of lightning protection for the power meter and meter reading equipment power supply of the power exceeding standard system by connecting the surge overvoltage and other potential processing circuits in the meter box, and realizes the power supply of the power meter and meter reading equipment. Lightning protection, strong protection ability, low residual voltage, and the protection effect of the utility model does not depend on the grounding resistance, no matter whether it is grounded or not, it can have a good protection effect;

(2) The utility model is directly matched with the electric meter box in the application process, and the installation and maintenance are convenient. At the same time, the use of the utility model can avoid the trouble of excavating the ground in a large area for the electric meter box to protect the lightning surge. It is beneficial to reduce the cost of grounding resistance, effectively save steel resources, and avoid material waste.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application and not to limit the present application.

Fig. 1 is the schematic diagram of the surge overvoltage equipotential processing circuit of the present utility model;

Fig. 2 is the schematic diagram of the protector warning circuit of the present utility model;

Fig. 3 is the installation structural diagram of the utility model in the electric meter box;

Among them: 1. Power metering integrated protector, 2-meter box master switch, 3-user sub-switch, 4-user meter, 5-warning light, 6-thermal tripping device.

detailed description:

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

The following embodiment is a typical implementation of the present application, as shown in Figure 1, a comprehensive protector for power metering, including a protective shell, a protector warning circuit and a wave connected between the power phase line and the neutral line The surge overvoltage equipotential processing circuit, the protector warning circuit and the surge overvoltage equipotential processing circuit are all located in the protective shell, and the surge overvoltage equipotential processing circuit includes three varistors connected in parallel And the gas discharge tube GDT3 connected in series between the varistor and the ground wire to avoid leakage current and unnecessary power consumption.

Both sides of the gas discharge tube GDT3 are connected in parallel with an overcurrent protection resistor R4.

There are three phase wires of the power supply, namely L1, L2, and L3, and the three varistors are respectively RV1, RV2, and RV3. Each varistor is correspondingly connected to a phase wire of the power supply, namely L1, L2, L3 is connected to the RV1, RV2 and RV3 correspondingly. At the moment of the surge, the surge enters the power interface L1, L2, L3 or N of the arrester along the wire, that is, the power phase line or the neutral line, and the power phase line and The instantaneous voltage difference of the neutral line N of the power supply rises, and the varistor conducts instantaneously, reducing the instantaneous voltage difference to zero, thereby realizing full protection between the phase line and the neutral line, and between the phase line and the ground line.

The protector warning circuit includes a warning lamp 5, a current limiting resistor R and a thermal tripping device 6, the warning lamp 5 is connected to the phase line of the power supply, one end of the thermal tripping device 6 is connected to the current limiting resistor R, and the other end Connect to the neutral wire N of the power supply.

There are three thermal tripping devices 6, and a thermal tripping device 6 is pasted on each of the three piezoresistors. It can be seen from FIG. 2 that each thermal tripping device has three contacts. One of the contacts is connected to the neutral line N of the power supply, and a shrapnel is installed on the contact. The connection relationship between the shrapnel and other contacts in the case of a non-circuit fault is shown in the solid line in Figure 2. In the case of surge overvoltage, etc. When the potential processing circuit works normally, the warning circuit is in a non-conductive state. When the surge overvoltage and other potential processing circuits fail, if RV1 is damaged, the temperature of RV1 will rise due to the voltage difference between L1 and N. , so that the shrapnel bounces to another contact, as shown in Figure 2, the warning circuit is turned on, and the warning light turns on, reminding the staff that the surge overvoltage equipotential processing circuit is faulty.

The protective shell is an aluminum alloy protective shell, and a transparent window is arranged on the protective shell, and the warning light 5 is located directly below the transparent window.

The side wall of the protective shell is provided with a plurality of cooling holes, and the cooling holes are louver cooling holes, which can facilitate the heat dissipation of the comprehensive protector for electric power metering while preventing dust.

The top of the protective shell is also provided with a wiring port, and the three phase wires of the power supply are connected to the piezoresistors inside the protective shell through the wiring ports.

The protective shell is bolted to one side of the main power switch 2 in the meter box (as shown in Figure 3).

The maximum current carrying capacity of the surge overvoltage equipotential processing circuit is 100KA.

The working principle of the utility model surge overvoltage equipotential processing circuit is as follows:

When the surge voltage invades the power line L or N, the varistor and the gas discharge tube GDT in the high-resistance state are turned on instantaneously to realize the voltage equalization of N and PE, forming an equipotential voltage equalization. At the same time, between the live line and the neutral line, Between the live wire and the ground wire, between the neutral wire and the ground wire, the same circuit is used for voltage equalization to achieve instantaneous balance, so that no potential difference will be formed and a large current will not be generated, so the normal operation of the back-end equipment can be protected. In addition, the utility model does not need to be connected to the ground wire. When the ground wire is not connected, it is not necessary to add a gas discharge tube, and the effect of voltage equalization can be realized only by the piezoresistor.

As shown in Figure 3, the installation structure of the present utility model is:

At present, three-phase four-wire power supply is mostly used in rural areas. The power metering comprehensive protector 1 is installed in the meter box. The three phase-connected wires of this device are respectively connected to the three phase lines in the meter box. The neutral wire connection inside the meter box,

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Although the specific implementation of the utility model has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, those skilled in the art do not need to Various modifications or deformations that can be made with creative efforts are still within the protection scope of the present utility model.

Claims (10)

1. A kind of 1. electric-power metering comprehensive protection device, it is characterised in that：Including guard shield, protector warning circuit and it is connected to electricity The electricity such as the overvoltage surge equipotential process circuit between source phase line and zero line, the protector warning circuit and overvoltage surge Position process circuit is respectively positioned in the guard shield, and the overvoltage surge equipotential process circuit includes parallel with one another three Piezo-resistance and the gas-discharge tube being connected between the piezo-resistance and ground wire, the both sides of the gas-discharge tube also and connect There is overcurrent protection resistance.
2. A kind of 2. electric-power metering comprehensive protection device according to claim 1, it is characterised in that：The power supply phase line is three Bar, respectively L1, L2, L3, three piezo-resistances are respectively RV1, RV2 and RV3, and each piezo-resistance is corresponding to be connected with One power supply phase line.
3. A kind of 3. electric-power metering comprehensive protection device according to claim 1, it is characterised in that：The protector warning circuit Including warning lamp, current-limiting resistance and thermal release device, the warning lamp is connected with power supply phase line, one end of the thermal release device Current-limiting resistance is connected, the other end is connected with zero-power line.
4. A kind of 4. electric-power metering comprehensive protection device according to claim 3, it is characterised in that：The thermal release device is three It is individual, in three piezo-resistances it is each corresponding to be pasted with a thermal release device.
5. A kind of 5. electric-power metering comprehensive protection device according to claim 3, it is characterised in that：The guard shield closes for aluminium Golden guard shield, the guard shield are provided with transparent window, and the warning lamp is located at the underface of the transparent window.
6. A kind of 6. electric-power metering comprehensive protection device according to claim 5, it is characterised in that：The side wall of the guard shield It is provided with multiple heat emission holes.
7. A kind of 7. electric-power metering comprehensive protection device according to claim 6, it is characterised in that：The heat emission hole is Baiyesan-medicinal powder Hot hole.
8. A kind of 8. electric-power metering comprehensive protection device described in claim 2 or 5, it is characterised in that：The top of the guard shield Wiring port is additionally provided with, three power supply phase lines are connected by the Wiring port with the piezo-resistance inside guard shield.
9. A kind of 9. electric-power metering comprehensive protection device according to claim 5, it is characterised in that：The guard shield bolt connects It is connected on the side of ammeter box interior power master switch.
10. A kind of 10. electric-power metering comprehensive protection device according to claim 1, it is characterised in that：Described overvoltage surge etc. The maximum current bearing capacity of current potential process circuit is 100KA.