JPH06245365A - Electric shock preventer - Google Patents

Abstract

PURPOSE:To prevent electric shock even when an earth leakage breaker is faulty by providing a current detecting means for earth wire and a decision means deciding earth leakage when the current detecting means detects a current whereas deciding defective earth when no current flow between a hot side wiring and the earth. CONSTITUTION:A leak current flows through an earth wire 17 connecting between an electrode 57 and an earth terminal 55 when a heater 44 in a bath unit 42 leaks, for example. Consequently, a photocoupler 20 emits light to deliver a signal from the output part C thereof to an OR gate 27 and thereby a transistor 30 is turned ON to excite a coil R thus turning a power supply contact R1 OFF. When an earth terminal 55, an earth line 56, or the like is not grounded sufficiently, photocouplers 15, 16 inserted into earth lines 4, 5 do not emit light. Consequently, 'L' levels are delivered from output sections A and B and a NAND gate 25 is turned ON to deliver a signal to the OR gate 27 for turning the transistor 30 ON thus exciting the coil R and turning the contact R1 OFF.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric shock prevention device,
More specifically, the present invention relates to an electric shock preventive device capable of preventing electric shock even if the earth leakage breaker is out of order, but is not particularly limited, but an electric heater as a heating source, a pump for forcibly circulating hot water, etc. The present invention relates to an electric shock preventive device suitable for application to a bathtub device including a driving motor or the like.

[0002]

2. Description of the Related Art Generally, electric shock occurs when an electric device such as an electric motor or an electric heater fails, and an electric circuit is formed in the order of, for example, the hot side of an electrode of AC 100 V, a metal part of the failed electric device, a person, and a ground. , Says that electric current flows to humans. Therefore, even if the hot side of the electrode flows into the metal part of the defective electric device, the electric current can be prevented by causing almost no current to flow in the human-grounded circuit. Alternatively, even if a metal part of an electric device, a person, a ground, and an electric circuit are formed and an electric current flows through the person, if this is detected before the lethal amount is reached and the power is cut off, electric shock is prevented. The former method is, for example, a washing machine, a refrigerator, or
It is implemented in bathtub equipment, electric water heaters, etc. The latter method is also known as an earth leakage breaker and is also installed in the above equipment. On the other hand, bathtub devices have been variously improved in order to improve life and improve health, and bathtub devices that allow users to enjoy bathing 24 hours a day have been proposed. The applicant of the present invention has also proposed a bathtub device of this type, for example, in Japanese Utility Model Publication No. 3-31376 and Japanese Patent Application Laid-Open No. 62-160116. These bathtub devices include
Heater for heating hot water, heater for hot water, filter,
Since electric equipment such as a pump for forcibly circulating between active layers and the like and an ozone gas generator for sterilization are provided, they are grounded and an earth leakage breaker is also provided as appropriate.

[0003]

Since the electric equipment as described above is provided with the earth leakage breaker, it is safe for the time being. However, the earth leakage breaker turns off the power source by detecting the imbalance of the current when there is an earth leakage, and even if the earth leakage breaker is provided, it is not always safe. That is, the earth leakage breaker itself may fail, and if there is no abnormality in the earth leakage breaker itself and the grounding is poor, the earth leakage breaker does not operate even if the earth leakage occurs, and the earth leakage breaker does not operate. And it starts to work only when the electric shock current flows. Therefore, there is a drawback of being electrocuted even in a short time. At this time, the leakage breaker may not operate depending on the value of the electric shock current, and dangerous current may continue to flow. In addition, even if the above-mentioned electric equipment is securely grounded, even if no earth leakage breaker is provided, the electric equipment side will be close to zero volt when a leak occurs, so there will be no leakage. When a person touches an electric device that is in use, almost no electric current flows through the human body, and therefore, the problem of electric shock does not occur.
However, sometimes it is forgotten to ground, and even if it is grounded, grounding may be defective. In addition, even if the ground is securely grounded, the ground may deteriorate over time, resulting in poor grounding. In such a state, if the electric device comes into contact with the electric current when the electric leakage occurs, the electric leakage current flows to the human body to cause an electric shock.

According to a simulated earth leakage test entrusted by the present inventor, even if the earth leakage breaker and the earth are connected and the earth leakage breaker is normally operating, it is dangerous for a short time before the earth leakage breaker operates to the human body model. The electric current flowed. In addition, the said test was performed with the bathtub apparatus, the hole was opened in the sheath of the sheath heater, and 2% salt water was used as bath water. As described above, even if the earth leakage breaker is operating normally, a dangerous current flows for a short time until the earth leakage breaker operates, but it is not perfect. However, there is an opinion that even if the electric current flows to the human body for a short time, there is no danger if it can be cut off within a certain time. However, in the case of electric shock in a bathtub, pool, etc., in a place where a secondary disaster such as drowning rather than a primary disaster is a concern, the ventricular fibrillation current, not the accompanying current 5 m
"Ground fault protection and grounding technology" announced at the Japan Electrical Association that A will be a problem. In addition, on page 384 of the “Electrical Appliance and Material Safety Research Report”, page 384, regarding the effects of 60-cycle AC on the human body, there is no sense at 1 mA or less, but at 5 mA or more, there is a painful shock and 10 mA. It has been reported above that muscles may be locally contracted and may not be separated from the circuit.

As described above, since electric leakage is dangerous, it is important to prevent the electric leakage from occurring, and it is necessary to take measures against the occurrence of the electric leakage. It is also important. However,
As described above, the conventional earth leakage breaker does not operate even if the earth leakage occurs when the earth is imperfect, and it may fail. Furthermore, the grounding method may not be completely grounded, and both methods are not perfect. Therefore, an object of the present invention is to provide an electric shock preventive device capable of preventing electric shock even if the earth leakage breaker is out of order. Still another object of the present invention is to provide an electric shock preventive device in a bathtub device without the risk of electric shock.

[0006]

The above object of the present invention is to:
When an electric leakage occurs, immediately detect it and give an alarm, take measures such as turning off the power supply, and even if the earth is defective, immediately detect it and give an alarm, take measures such as turning off the power supply. If taken, it will be achieved. That is, electric shock is prevented. Therefore, the invention according to claim 1 is an electric shock prevention device in an electric device in which electric power is supplied to an electric device such as a motor or a heater by a hot-side distribution line and a ground line. The electric shock preventive device comprises an earth wire connected to the electric equipment or a conductor electrically connected to the electric equipment, a current detection means provided on the earth wire, and a judging means. The means is configured to determine that the current is leaked when the current detecting means detects the current, and to determine the ground failure when the current does not flow between the hot-side distribution line and the ground, and output the signal. According to a second aspect of the invention, the electric device is composed of a bathtub device.

[0007]

Since the invention according to claim 1 is configured as described above, no leakage current flows through the ground wire when no electrical leakage occurs in the electrical equipment. Therefore, neither the current detecting means nor the determining means operates. When the insulation state of the electric device deteriorates and the hot side is electrically connected to the electric device or a conductor electrically connected to the electric device, a leakage current flows through the ground wire, and the current detection means detects this. Then, the determination means outputs a leakage signal. Take measures such as turning off the power or issuing a leak alarm by this leak signal. If the ground wire becomes defective, no current will flow to the ground wire on the hot side of the distribution line. Then, the determination means outputs a ground failure signal. Take action such as turning off the power supply or issuing a ground fault alarm by this signal. Since the electric equipment according to the second aspect of the present invention is a bathtub device, when electric leakage or ground failure occurs in the bathtub device, it operates as described above.

[0008]

The present invention can be implemented in various forms. For example, a minute current may be made to flow through the ground wire, and the current detecting means may be implemented by a transistor that also detects a minute current or voltage. Further, the discriminating means outputs a leakage signal or a grounding failure signal, but instead of shutting off the power source based on these signals, an alarm may be issued by voice, display or the like. However, in the accompanying drawings, the current detection means is shown as an example implemented by a photocoupler, and an example in which the power is cut off by a leakage signal or a ground fault signal from the output part of the photocoupler.

The present invention is equally applicable to washing machines, refrigerators, bath tubs, electric water heaters and the like in which electric equipment such as electric motors and heaters are used. explain. In the first embodiment shown in FIG. 1A, the bathtub device 40 includes a bathtub 41 and a bath device 42. In the casing 43 of the bath device 42, the Japanese Patent Publication No. 3-519 proposed by the applicant.
84, Jikken 3-31376, JP-A-62-160.
No. 116 or the like, a heater 44 for heating bath water, a pump P drive for forcibly circulating the bath water between the heater 44, the filter 46, the active tank 47 filled with barley stone, and the like. In addition to electric appliances such as an electric motor for sterilization and an ozone gas generator 48 for sterilization, a controller for controlling various devices so that the user can take a bath 24 hours a day is provided. The bath device 42 and the bathtub 41 are connected by circulation pipes 50 and 51. An underwater electrode 57 is provided in the circulation pipe 50. An earth terminal 55 is provided on the casing 43 of the bath device 42, and the earth terminal 55 is grounded by an earth line 56. The bath device 42 is connected to an AC power supply, which will be described later, so that electric power is appropriately supplied to the heater 44, the motor and the like.

AC power is transmitted from the power plant at high voltage,
And, for example, it is supplied to the customer after it is lowered to a predetermined voltage with a pole transformer, but one of them is a single-phase two-wire type,
Even if it is a single-phase three-wire type, it is grounded to form the ground line 1, and the other side forms the hot-side distribution line 2. The lines 1 and 2 are provided with a b-contact R. Ground wire 1
, And ground wires 4 and 5 are connected to the hot-side distribution line 2, respectively. And these earth lines 4 and 5,
Photocoupler 1 with resistors 7 and 8 and diodes 9 and 10
5 and 16 are respectively interposed. Photo coupler 15,
The outputs A and B of 16 are connected to the input terminal of a NAND gate 25, and its output line 26 is connected to one input terminal of an OR gate 27, as shown in FIG. ing.

The ground wire 17 connecting the electrode 57 in the circulation tube 50 and the ground terminal 55 is also provided with the photocoupler 20 together with the resistor 18 and the diode 19. The output C of the photocoupler 20 is connected to the other input terminal of the OR gate 27. The output line 28 of the OR gate 27 is connected to the base of the transistor 30. Therefore, when a predetermined voltage is applied to the base of the transistor 30, the coil R for the relay R is energized.

Next, the operation of the above embodiment will be described.
Since the contact R1 is a b-contact type, when the power is turned on, electric power is supplied into the bath device 42, and the controller thereof appropriately energizes the pump 45, the heater 44, etc., and the bath water is forcibly circulated. Heated and purified. In particular, according to this embodiment, the bath water is purified by the bacteria growing on the barley stone in the active tank 47, but organic substances having a large molecular weight that the bacteria cannot process are removed by ozone gas injected from the ozone generator 48. Can be decomposed into a molecular weight that can be treated. In addition, ozone gas becomes dissolved oxygen, which helps the growth of aerobic bacteria and further promotes purification.

When in such an operating state, the pump 4
5, there is no electric leakage in the heater 44, and the earth terminal 5
5. The places where corrosion easily occurs, such as the earth line 56, are normal.
In a normal state of being surely grounded, no current flows through the ground wire 17 connecting the electrode 57 and the ground terminal 55. Therefore, the photocoupler 20 provided on the ground line 17 does not emit light, and the signal from its output C to the OR gate 27 is not input. On the other hand, ground line 1
Since no current flows through the ground wire 4 of the photo coupler 15,
“L” is output from the output unit A of the. Since the current set by the resistor 8 flows through the ground wire 5 of the hot-side distribution line 2, the light emitting diode emits light and "H" is output from the output section B. By the way, since the output parts A and B are connected to the NAND gate 25, the NAND gate 25 does not turn on. That is, no signal is input to the OR gate 27. Therefore, the transistor 30 remains off and the contact R
1 maintains the ON state, and the bathtub device 40 operates normally.

Next, for example, the heater 44 in the bath device 42.
It is assumed that there is a short circuit. Then, a leakage current flows through the ground wire 17 that connects the electrode 57 and the ground terminal 55. Therefore, the photocoupler 20 emits light, the signal from the output portion C to the OR gate 27 is input, the transistor 30 is turned on, the coil R is excited, and the contact R1 of the power supply is turned off. In this way, electric shock is prevented in advance. By the way, when the earth terminal 55, the earth line 56, etc. are not properly grounded, no leakage current flows even if a leakage occurs.
Therefore, the photocoupler 20 does not emit light, and the signal from its output C to the OR gate 27 is not input. However, when the ground terminal 55, the ground line 56, etc. are not properly grounded, no current flows through the ground wire 4 of the ground wire 1 and the ground wire 5 of the hot-side distribution wire 2.
A photo coupler 1 provided on these ground wires 4 and 5.
5 and 16 do not emit light. Therefore, its output parts A, B
Outputs "L". By the way, since the output parts A and B are connected to the NAND gate 25, the NAND gate 25 is turned on and a signal is input to the OR gate 27. Therefore, the transistor 30 is turned on and the coil R
Is excited to turn off the contact R1.

As described above, according to the present embodiment, the power is cut off when the earth leakage occurs when the earth is perfect, and the electric power is cut off even when the earth is imperfect, so that no electric shock accident occurs. Moreover, according to the present embodiment, the photocoupler 20 is provided on the ground wire of the conventional electric device, and the ground wire 1 is provided.
, And the ground wires 4 and 5 are connected to the hot-side distribution line 2, and these ground lines 4 and 5 are similarly connected to the photocoupler 1.
An electric shock prevention device can be obtained at low cost simply by interposing 5, 16 and forming a logic circuit. Further, according to the present embodiment, since the ground lines 4 and 5 in which the photocouplers 15 and 16 are interposed are connected to both lines 1 and 2 of the power source, which line is the hot side distribution line? The effect that the labor of inspecting can be saved can be obtained. That is, the effect of eliminating wiring mistakes can be obtained.

Next, a second embodiment of the present invention will be described with reference to FIG. The same members as those in the first embodiment described above include
The same reference numerals are attached and duplicate explanation is not given. According to the present embodiment, the ground wire 1 and the hot-side distribution line 2 have a
A contact point R2 is provided. The ground line 1 and the hot-side distribution line 2 are connected by a line 62 in which resistors 60 and 61 are interposed, and a ground line 63 extends from a point divided by the resistors 61 and 62. A photocoupler 65 is provided on the ground wire 63. Also, part of the circulation pipe 50
A good electrical conductor 66 composed of a good electrical conductor 66 such as metal
A ground electrode 67 is provided outside the. In this way, when the circulation pipe 50 is made of metal and the bathtub 41 is also made of metal, the circulation pipe 50, the bathtub 41, and the like have the same potential as the ground, and in the configuration as shown in FIG. In some cases, the leakage current does not flow even if the photo coupler leaks.
Therefore, as indicated by 68, the photocoupler 20 is provided in parallel to the line in which the diodes are connected in series, and when a leakage occurs in the circulation pipe 50 or the like, a current flows through the photocoupler 20 to emit light. ing. The output D of the photocoupler 65 is, as shown in FIG.
The output C of the photocoupler 20 is connected to one input terminal of the D gate 79, and is connected to the other L active input terminal of the AND gate 79.

According to this embodiment, the same action and effect as those of the above-mentioned first embodiment can be obtained. That is, the earth terminal 55, the earth line 56, etc. are surely earthed,
When there is no electric leakage in the pump 45, the heater 44, etc., the electrode 6
No current flows through the ground wire 17 that connects 7 and the ground terminal 55. Therefore, the photocoupler 20 does not emit light, and the "L" signal is inverted and the "H" signal is input from the output portion C to the AND gate 69. On the other hand, since a current flows from the hot-side distribution line 2 to the ground line 63, the light emitting diode emits light and “H” is output from the output section D.
Therefore, the AND gate 69 is turned on, the transistor 30 is turned on, and the coil R is excited. The contact point R2 is maintained in the ON state, and the bathtub device 40 is normally operated.

Next, for example, the heater 44 in the bath device 42
If a leakage occurs from the electrode 67 and the earth terminal 55
A leakage current flows through the ground wire 17 that connects to the. Therefore, the photocoupler 20 emits light, and the output section C outputs an AND signal.
The “H” signal is inverted and the “L” signal is input to the gate 69. Therefore, the AND gate 69 does not turn on regardless of "H" or "L" of the signal from the output D of the photocoupler 65 that is input to the other terminal of the AND gate 69. Therefore, the transistor 30 is turned off, the coil R is demagnetized, and the contact R2 is turned off. In this way, electric shock is prevented in advance. On the other hand, the earth terminal 55,
When the earth line 56 or the like is not properly grounded, no current flows in the earth line 63, so that the photocoupler 65 does not emit light and its output D outputs “L”. Therefore, A
Regardless of "H" or "L" of the signal from the output portion C of the photocoupler 20 input to the other terminal of the ND gate 69,
That is, the AND gate 69 does not turn on regardless of whether or not there is a leakage. Therefore, the transistor 30 turns off and the contact R2 turns off.

As described above, according to the second embodiment, the contact point R2 provided on the ground line 1 and the hot side distribution line 2 is provided.
Since it is an a-contact type, when the electric leakage occurs or the grounding is defective, the power is cut off and the electric shock is prevented, and the effect that the power is not turned on unless the repair or the like is performed is obtained. Also, the ground wire 1 and the hot side distribution wire 2 are
It is connected by a ground wire 63 and is structurally simplified as compared with the first embodiment. Furthermore, since the ground electrode 67 is provided outside the good electrical conductor 66, there is also an effect that maintenance management can be simplified.

[0020]

According to the present invention, there is provided an antistatic device, in which an earth wire connected to an electric equipment or a conductor electrically connected to the electric equipment, and a current detecting means provided on the earth wire. When the current detecting means detects a current, the judging means judges that there is a leakage, and when no current flows between the hot side distribution line and the ground, it judges that there is a ground failure, and Since the signal is output, the effect peculiar to the present invention can be obtained in that the electric power can be prevented in advance even when the electric leakage occurs or the grounding is defective. According to the second aspect of the invention, since the electric device is the bathtub device, there is an effect that, as described above, there is no fear of electric shock and the user can safely enjoy the bath.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention, in which (a) is a schematic view showing a part of a bath device in cross section, and (b) is a logic circuit diagram.

FIG. 2 is a diagram showing a second embodiment of the present invention, in which (a) is a schematic diagram showing a part of a bath device in cross section, and (b) is a logic circuit diagram.

[Explanation of symbols]

 1 Ground wire 2 Hot side distribution wire 4, 5, 17, 63 Ground wire 15, 16, 20, 65 Photo coupler A, B, C, D Output section

Claims (2)

[Claims] 1. An electric shock preventive device in an electric device in which electric power is supplied to electric equipment such as a motor and a heater by a hot-side distribution line and a ground line. A ground wire connected to the electric device or a conductor electrically connected to the electric device,
The grounding wire comprises a current detecting means and a judging means. When the current detecting means detects a current, the judging means judges that there is a leakage, and a current flows between the hot side distribution line and the ground. An electric shock prevention device characterized in that when there is no ground, it is judged to be a ground failure and that signal is output. 2. An electric shock prevention device in which the electric device according to claim 1 is a bathtub device.