CN204391681U - Earth leakage protective device - Google Patents

Abstract

The utility model provides a kind of earth leakage protective device, first current transformer is through live wire, zero line, second current transformer is through PE line, first current transformer is connected with leakage current judging unit respectively with the second current transformer, leakage current judging unit be used for when the first current transformer and/or the second current transformer detect live wire, zero line and/or PE line exist Ground leakage current reach set point time, transmission warning signal to control module; Control module, is connected with main switch and PE line control switch respectively, and when receiving the warning signal of self-detection module, control main switch and PE line control switch disconnect simultaneously; Main switch, it is connected with live wire and zero line respectively, its conducting, the conducting disconnecting control live wire and zero line, open circuit; PE line control switch, it is connected with PE line, its conducting, the conducting disconnecting control PE line, open circuit.Its main switch and zero line switch and PE wiretap are synchronous.The utility model can play the effect of omnibearing protection.

Description

leakage protector

technical field

The utility model relates to the field of electric power, in particular to a leakage protector.

Background technique

The existing leakage switch or leakage protector detects and controls the unbalanced current △In generated by the phase-to-earth leakage to achieve the purpose of protection, but it cannot play a protective role when the N.PE line is charged, but will cause electric shock or death.

At present, the domestic low-voltage power supply system is formulated according to the IEC-TN standard. Since the IEC TN system has defects when it is formulated, it has been improved and TN-C, TN-C-S, and TN-S have appeared, but they have not jumped out of TN. The scope of the system, so the flaws are always there. In order to make up for the defects of the TN system, people have developed a leakage protector for the TN system specification, but because it is also developed according to the TN system specification, it only makes up for some of the defects of the TN system, and cannot completely solve the TN system. The fundamental problems in the system lead to the possibility of electric shock during operation.

Contents of the invention

The purpose of this utility model is to provide a leakage protector, which will not cause electric shock or fatal accident even when the N.PE line is charged, so as to achieve the complete separation of the electrical appliances and the power grid, and play the role of all-round protection.

In order to achieve the above purpose, the utility model provides a leakage protector, including a leakage current detection module, a control module, a main switch and a PE line control switch, wherein:

The leakage current detection module includes a leakage current judging unit, a first current transformer and a second current transformer, the first current transformer passes through the live wire and the neutral wire, the second current transformer passes through the PE line, the first current transformer and The second current transformers are respectively connected with the leakage current judging unit, and the leakage current judging unit is used for when the first current transformer and/or the second current transformer detects that the live wire, the neutral wire and/or the PE wire have a ground leakage current reaching the set level. When setting a value, send a warning signal to the control module;

The control module is connected to the main switch and the PE line control switch respectively, and when receiving the warning signal from the leakage current judgment, controls the main switch and the PE line control switch to be disconnected at the same time;

The main switch is connected to the live wire and the neutral wire respectively, and its conduction and disconnection control the conduction and disconnection of the live wire and the neutral wire;

The PE line controls the switch, which is connected to the PE line, and its conduction and disconnection control the conduction and disconnection of the PE line.

During implementation, the main switch and the PE line control switch are respectively synchronously controlled contacts in one switch.

Compared with the prior art, the leakage protector of the present utility model will not cause electric shock or fatal accident even when the N.PE line is electrified, achieves the complete separation of the electrical appliances and the power grid, and plays the role of all-round protection.

Description of drawings

Fig. 1 is the structural diagram of a specific embodiment of the leakage protector of the present utility model;

Fig. 2 is the structural diagram of another embodiment of the leakage protector of the present utility model;

Fig. 3 is a structural diagram of a specific embodiment of the leakage protector of the present invention;

Fig. 4 is a structural diagram of another specific embodiment of the leakage protector of the present invention.

Detailed ways

Since the current TN-S system is running because the N and PE lines are connected at one point, in the system three-phase unbalanced phase failure, single-phase grounding, third harmonic, single-phase (instantaneous) grounding or N, PE work and protective grounding When the terminal resistance becomes larger and the open circuit is open, there are different levels of voltage and current in the N line. The casing of the electrical appliance is generally connected to the PE line (ie, the N.PE line). When the LN line has leakage, the △In current generated exceeds When the setting value is set, the leakage protector acts and disconnects the power supply, which achieves the purpose of protection. However, when the N and PE lines are charged, only the L1 line, L2 line, L3 line, N line, PE line and the user line are disconnected by the leakage protector. The shell of the electrical appliance is connected, because the N and PE wires are connected at one point, that is, the shell of the electrical appliance is not disconnected from the power supply of the electrical appliance, and the shell of the electrical appliance and the N wire are at the same potential, which may cause electric shock or death.

Therefore, the utility model provides a leakage protector, which adds a group of PE line control switches synchronously controlled with the main switch contacts on the PE line to cut off the PE line, so that the electrical appliances are completely disconnected from the power supply to achieve the purpose of protection.

As shown in Figure 1, the circuit diagram when the leakage protector of the present utility model is applied to a three-phase five-wire circuit, the leakage protector of the present utility model includes a detection module 11, a control module 12, a main switch 13 and a PE line control switch 14, in,

The leakage current detection module 11 includes a leakage current judging unit, a first current transformer and a second current transformer. The first current transformer passes through the live wire and the neutral wire, the second current transformer passes through the PE line, and the first current transformer passes through the PE line. The current transformer and the second current transformer are respectively connected with the leakage current judging unit, and the leakage current judging unit is used for when the first current transformer and/or the second current transformer detect that there is a leakage current to the ground in the live line, the neutral line and/or the PE line When the set value is reached, a warning signal is sent to the control module 12;

The control module 12 is connected to the main switch 13 and the PE line control switch 14 respectively, and when receiving a warning signal from the leakage current judgment unit, controls the main switch 13 and the PE line control switch 14 to be disconnected simultaneously;

Main switch 13, which is respectively connected to the live wire and the neutral wire, and its conduction and disconnection control the conduction and disconnection of the live wire and the neutral wire;

The PE line controls the switch 14, which is connected to the PE line, and its conduction and disconnection control the conduction and disconnection of the PE line.

According to a specific embodiment, the circuit diagram of the leakage protector of the present invention is applied to a single-phase circuit.

During implementation, as shown in Fig. 3 and Fig. 4, the main switch and the PE line control switch can be synchronously controlled contacts in a switch respectively.

The leakage protector of the utility model increases the detection of the leakage current of the PE line to the ground, and realizes that the PE line is disconnected from the neutral line and the live line synchronously when the leakage current is detected to exceed the set value, thereby achieving the purpose of making the electric appliance The purpose of protecting completely from the power supply.

The above description is only illustrative of the present utility model, rather than restrictive. Those of ordinary skill in the art understand that many modifications, changes, or Equivalent, but all will fall within the protection scope of the present utility model.

Claims (2)

1. an earth leakage protective device, is characterized in that, comprises leakage current test module, control module, main switch and PE line control switch, wherein:

Leakage current test module comprises leakage current judging unit, the first current transformer and the second current transformer, first current transformer is through live wire, zero line, second current transformer is through PE line, first current transformer is connected with leakage current judging unit respectively with the second current transformer, leakage current judging unit be used for when the first current transformer and/or the second current transformer detect live wire, zero line and/or PE line exist Ground leakage current reach set point time, transmission warning signal to control module;

Control module, is connected with main switch and PE line control switch respectively, and when receiving the warning signal judged from leakage current, control main switch and PE line control switch disconnect simultaneously;

Main switch, it is connected with live wire and zero line respectively, its conducting, the conducting disconnecting control live wire and zero line, open circuit;

PE line control switch, it is connected with PE line, its conducting, the conducting disconnecting control PE line, open circuit.

2. earth leakage protective device as claimed in claim 1, it is characterized in that, main switch, PE line control switch are respectively the contact of the Synchronization Control in a switch.