Leakage protection method and device having live/neutral wire identification function

Patent metadata

Field	Value
Publication number	US-9941685-B2
Application number	US-201414767915-A
Country	US
Kind code	B2
Filing date	Feb 20, 2014
Priority date	Feb 23, 2013
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A leakage protection method and device with live/neutral wire identification that identify live wire and neutral wire of a power supply by means of a live/neutral wire identification device, and correct live/neutral wire connections, so that a surface leakage signal pickup device is always connected to the neutral wire and to surface of the electric device, and electric potential of the surface is always monitored over the neutral wire. When the Surface leaks electricity, the leakage signal pickup device immediately drives an electromagnetic tripping device to break a main circuit switch, thereby breaking the connection between the electric device and the power source. The method and device work effectively even when the electric device is not grounded.

First claim

The invention claimed is:

1. A method of electric leakage detection comprising below steps:
(1) Identify a live wire (L) or a neutral wire (N) of a power source;
(2) If it is discovered that the live wire (L) is erroneously connected to a neutral wire (N′) of an electric device or the neutral wire (N) is erroneously connected to a live wire (L′) of an electric device due to the live/neutral wires are erroneously connected, then, change connections of a “surface leakage detection device” from connecting between a surface wire (F′) and the neutral wire (N′) of the electric device into connecting between the surface wire (F′) and the live wire (L′) of the electric device; or, reconnect the live wire (L′) to the live wire (L) and the neutral wire (N′) to the neutral wire (N); or, a main circuit switch (K) is made such that the main circuit switch (K) cannot close circuit or that the main circuit switch (K) breaks circuit immediately after closing the circuit;
(3) The “surface leakage detection device” which is connected between the surface wire (F′) and the neutral wire (N), monitors electric leakage of the electric device's surface, once the leakage is found, immediately breaks the main circuit switch (K) which connects the power source and the electric device.

2. The method of claim 1 , wherein the steps may be included in an inevitable manual operation and triggered or implemented by a manual operation.

3. The method of claim 1 , wherein the identification of the live wire (L) or the neutral wire (N) of the power source comprise:
(a) pre-lock a power supply circuit by making the circuit cannot be closed or breaks the circuit immediately after closing the circuit;
(b) check wiring of live/neutral wire of the power source; if it is wired correctly, unlock the power supply circuit so that the main circuit switch (K) may be closed; otherwise, remain the power supply circuit locked so that the main circuit switch (K) could not be closed, or, the main circuit switch (K) is broken immediately after being closed; by means of combination of (a) and (b), live/neutral wire pre-identification is guaranteed.

4. A device of electric leakage protection comprising: a live wire (L′) of an electric device which is connected to a liver wire (L) of a power source by default, a neutral wire (N′) of the electric device which is connected to a neutral wire (N) of the power source by default, a surface wire (F′) which is connected to the electric device's surface, a surface leakage signal pickup device ( 2 ), and an electromagnetic tripping device ( 3 ) which controls a main circuit switch (K); wherein the device of electric leakage protection further comprises a live/neutral Wire identification device ( 1 ) which is Ground independent; and the device ( 2 ) has one terminal connected to the surface wire (F′), another terminal connected to the neutral wire (N) through (N′) or through (L′).

5. The electric leakage protection device of claim 4 , wherein the surface leakage signal pickup device ( 2 ), may contain a current sensor (T) in which the live wire (L) and the neutral wire (N) of the power source go through, and one or multiple current path (I) connecting surface (F) of the electric device and the neutral wire (N) of the power source; the current path (I) consists components which allow current to flow, and one end of current path (I) is connected to the surface (F) of the electric device through the surface wire (F′) of the electric device, another end is connected to the neutral wire (N) of the power source in a node located before or after the current sensor (T).

6. The electric leakage protection device of claim 4 , wherein the surface leakage signal pickup device ( 2 ) contains electromagnetic relay or solid relay, the output contacts of the electromagnetic relay or solid relay are connected to coil of the electromagnetic tripping device ( 3 ) directly or through a driving circuit, coil of the electromagnetic relay is connected between the surface wire (F′) and the neutral wire (N) of the power source directly, or the coil of the electromagnetic relay in series with an impedance (Z) is connected between (F′) and (N); the impedance (Z) is either a variety of current limiting components, or rectifying components.

7. A device of live/neutral wire identification connecting the electric leakage protection device of claim 4 , wherein input of the device of live/neutral wire identification is connected to the live wire (L′) or the neutral wire (N′), output of the device is connected to the surface leakage signal pickup device ( 2 ) or the electromagnetic tripping device ( 3 ) or a live/neutral wire conversion switch ( 4 ), the device of live/neutral wire identification is Ground independent.

8. The live/neutral wire identification device of claim 7 , wherein the device, its input is connected to (L′) or (N′), its output is comprised of a group or multiple-group conversion switches or contacts; the surface leakage signal pickup device ( 2 ) has one terminal connected to (F′), one terminal connected to N via a conversion switch of the live/neutral wire identification device and (N′), in case of live/neutral wires are swapped causing the live wire (L′) connecting to the neutral wire (N) or the neutral wire (N′) connecting to the live wire (L), the live/neutral wire identification device is activated, its conversion switches or contacts reconnect the surface leakage signal pickup device ( 2 ) which is previously connected to the neutral wire (N) through the neutral wire (N′), to the neutral wire N through the live wire (L′).

9. The live/neutral wire identification device of claim 7 , wherein the device, its input is connected to the live wire (L′) or the neutral wire (N′), its output is comprised of a group or multiple-group conversion switches or contacts that consist the live/neutral wire conversion switch ( 4 ); the surface leakage signal pickup device ( 2 ) has one terminal connected to the surface wire (F′), one terminal connected to the neutral wire (N) via the neutral wire (N′), in case of live/neutral wires are swapped causing the live wire (L′) connecting to the neutral wire (N) or the neutral wire (N′) connecting to the live wire (L), the live/neutral wire identification device is activated, the live/neutral wire conversion switch ( 4 ) reconnects the live wire (L′) to the live wire (L) and the neutral wire (N′) to the neutral wire (N).

10. The live/neutral wire identification device of claim 7 , wherein the device, its input is connected to the live wire (L′) or the neutral wire (N′), its output is comprised of a group or multiple-group conversion switches or contacts; the surface leakage signal pickup device ( 2 ) has one terminal connected to the surface wire (F′), one terminal connected to the neutral wire (N) of the power source through (N′); in case of live/neutral wires are swapped causing the live wire (L′) being connected to the neutral wire (N) or the neutral wire (N′) being connected to live wire (L), the live/neutral wire identification device works or not works, a main circuit switch (K) which is controlled by output switches or contacts of the live/neutral wire identification device, is made such that it could not close circuit or that it breaks the circuit immediately after closing the circuit.

11. The live/neutral wire identification device of claim 7 , wherein the device, comprising a current limiting component (Z), a luminous component (B 1 ) and a touch electrode (A); (B 1 ) in series with (Z), one end is connected to (A), and another end is connected to the live wire (L) or the neutral wire (N) directly or through the live wire (L′) or the neutral wire (N′); the touch electrode (A) contains conductors that a person

Assignees

• Wu Wei

Inventors

• Wu Wei

Classifications

• H02H3/14

  responsive to occurrence of voltage on parts normally at earth potential {(monitoring earth connection H02H5/105)} · CPC title

• H02H3/162 Primary

  for AC systems · CPC title

• H02H11/002 Primary

  in case of inverted polarity or connection; with switching for obtaining correct connection · CPC title

• H02H3/16 Primary

  responsive to fault current to earth, frame or mass (with balanced or differential arrangement H02H3/26 {; monitoring earth connection H02H5/105}) · CPC title