Method of electricity leakage detection and prevention of electrical equipment's outer surface and system thereof

Patent metadata

Field	Value
Publication number	US-9928980-B2
Application number	US-201114350089-A
Country	US
Kind code	B2
Filing date	Dec 12, 2011
Priority date	Nov 12, 2011
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

Disclosed in the present invention are a method of electricity leakage detection and prevention of electrical equipment's outer surface and system thereof. The method and system are used for detecting and preventing electricity leakage of the electrical equipment's outer surface caused by defective insulation and power supply connection faults. Without in touch with the electrical equipment's outer surface, the electricity leakage of the outer surface can be detected and the connection between the electrical equipment and the power supply can be cut and an alarm is made by means of the current channel ( 2 ) formed between the electrical equipment neutral line (N′) and the electrical equipment's outer surface (G′) and the monitoring of the current value. A power supply channel ( 5 ) is set up to make sure that the electrical equipment can be normally operated via the system even in the condition of the power supply connection faults. According to the method and system, the electricity leakage of the outer surface can be correctly detected and the alarm can be made or the connection between the electrical equipment and the power supply can be cut even if the electrical equipment's outer surface is not grounded. With the advantage of simple construction and low cost, the system can be widely used.

First claim

The invention claimed is:

1. A method of electricity leakage detection and prevention, wherein the method comprises:
Presetting a current channel ( 1 ) between equipment's live line and neutral line, a current channel ( 2 ) between equipment's neutral line and equipment surface which is connected in series with the current channel ( 1 ); the equipment surface is not grounded; when leakage occurs on the equipment surface, a current will flow through the current channel ( 2 ); when a power supply's live line and neutral line being erroneously connected to the equipment's live line and the equipment surface, a current will flow through the channel ( 1 ) and the channel ( 2 );
Monitoring the current flowing through the current channel ( 2 ) caused by leakage and by faulty wiring;
In case of leakage and faulty wiring, the current flowing through the current channel ( 2 ) is greater than a preset threshold, tripping an amplification and execution circuit to alarm and/or remove power supply to the equipment.

2. The method of electricity leakage detection and prevention according to claim 1 , wherein the current flowing through the preset current channel ( 2 ) between the equipment's neutral line and the equipment surface, is preset being less than a current which is safe to pass through a human body, to prevent the possible hazard caused by measurement loop.

3. The method of electricity leakage detection and prevention according to claim 1 , wherein the amplification and execution circuit obtains power to work normally even in case of faulty wiring through a power channel which connects the equipment surface, the equipment's live line or the equipment's neutral line directly or indirectly.

4. A system of electricity leakage detection and prevention, comprising a detection circuit ( 3 ) and an amplification and execution circuit ( 4 ), wherein the system further comprises a current channel ( 2 ), which is connecting by conductive electronic components equipment's neutral line (N′) with equipment surface (G′) which is ungrounded to get a current flowing between (N′) and (G′) tripping the amplification and execution circuit ( 4 ) through the detection circuit ( 3 ), to alarm and/or remove power supply to the equipment in case of leakage occurs on the equipment surface; the system further comprises a current channel ( 1 ) which is connecting by conductive electronic components equipment's live line (L′) with the equipment's neutral line (N′), and is in series with the current channel ( 2 ) to get the current tripping the amplification and execution circuit ( 4 ) through the detection circuit ( 3 ), to alarm and/or remove power supply to the equipment in case of a power supply's live line (L) and neutral line (N) being erroneously connected to the equipment's live line (L′) and the equipment surface (G′).

5. The system of electricity leakage detection and prevention according to claim 4 , wherein said current channel ( 2 ) which is connecting the equipment's neutral line (N′) with the equipment surface (G′), has the value of conductive electronic components of the current channel ( 2 ) being set to ensure the maximum current flowing through the current channel ( 2 ) being less than a current which is safe to pass through a human body.

6. A power system connecting the system of electricity leakage detection and prevention described in claim 4 , wherein the power system comprises a power channel; input of the power channel is connected to the equipment surface (G′), the equipment's live line (L′) and/or the equipment's neutral line (N′), and output of the power channel is connected to the amplification and execution circuit ( 4 ), so that in case of a power supply's live line (L) and neutral line (N) being erroneously connected to the equipment's live line (L′) and the equipment surface (G′), the power channel inputs power through (L′) and (G′) and outputs enough power to drive the amplification and execution circuit ( 4 ); in case of the power supply's live line (L) and neutral line (N) being erroneously connected to the equipment's neutral line (N′) and the equipment surface (G′), the power channel inputs power through (N′) and (G′) and outputs enough power to drive the amplification and execution circuit ( 4 ).

7. The power system according to claim 6 , wherein the power channel comprises a three-phase rectifier bridge, three AC input terminals of the rectifier bridge are correspondingly connected to the equipment's live line (L′), the equipment's neutral line (N′), and the equipment surface (G′); positive terminal and negative terminal of output of the rectifier bridge are correspondingly connected positive terminal and negative terminal of power supply of the amplification and execution circuit ( 4 ).

8. The power system according to claim 6 , wherein the power channel comprise two diodes, the diodes are connected to each other by the same polarity then further connected to power supply of amplification and execution circuit unit of the amplification and execution circuit ( 4 ), one of remaining diode poles is connected to the equipment surface (G′), another remaining pole is connected to the equipment live line (L′).

9. The power system according to claim 6 , wherein the power channel comprise two conduct wires, the first conduct wire's one end is connected to the equipment surface (G′), the second conduct wire's one end is connected to the equipment's neutral line (N′), two remaining ends of the conduct wires are connected to two terminals of power supply of amplification and execution circuit unit of the amplification and execution circuit ( 4 ).

10. The power system according to claim 6 , wherein the power channel comprises two wire windings which are wound to the same electronic relay, one end of the first winding is connected to the equipment's live line (L′), while another end is connected to output terminal of one independent amplification and execution circuit unit; one end of the second winding is connected to the equipment surface (G′), while another end is connected to output terminal of another independent amplification and execution circuit unit.

Assignees

• Wu Wei

Inventors

• Wu Wei

Classifications

• H02H3/14 Primary

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

• H02H3/16

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

• H01H47/005 Primary

  Safety control circuits therefor, e.g. chain of relays mutually monitoring each other · CPC title

• H01H47/002

  Monitoring or fail-safe circuits · CPC title

• H02H3/162 Primary

  for AC systems · CPC title