CN211790722U - Ground wire electrification preventing protection device - Google Patents
Ground wire electrification preventing protection device Download PDFInfo
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- CN211790722U CN211790722U CN201922446159.7U CN201922446159U CN211790722U CN 211790722 U CN211790722 U CN 211790722U CN 201922446159 U CN201922446159 U CN 201922446159U CN 211790722 U CN211790722 U CN 211790722U
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Abstract
The utility model belongs to the technical field of the electrified protection of ground wire, specifically disclose a prevent ground wire electrified protection device, include: the input end of the first voltage relay is connected between a zero line and a ground wire of the protected circuit; the input end of the second voltage relay is connected between the ground wire and the equal potential point of the protected circuit; an intermediate element, an input end of which, a coil contact of the first voltage relay and a coil contact of the second voltage relay are connected in series and form a control loop; the intermediate element can output a control signal from the output end of the intermediate element after the control loop is conducted; and the detection input end of the executive component is connected with the output end of the intermediate component, and the output end of the executive component can disconnect the protected circuit. The utility model discloses a prevent ground wire electrification protection device can effectively prevent to cause the personal electric shock death accident because of the ground wire is electrified to take place.
Description
Technical Field
The utility model belongs to the technical field of the electrified protection of ground wire, concretely relates to prevent ground wire electrified protection device.
Background
The grounding wire in the house at present is mainly a wire for realizing safety protection, electric equipment (mainly a shell) in a house is well connected with the ground through the wire, and parts touched by people of the electric equipment are equipotential with the ground in the use process.
The ground resistance of normal consumer earth connection all requires to be less than 4 ohm, and all stands on the ground in the people's daily life, and people's foot and ground also are equipotential in theory, and human resistance generally all is greater than 100 ohm, in case the consumer insulation has punctured, the shell of equipment has electrified, can directly flow to the ground through the ground wire, even the people touches the electrical apparatus shell of electric leakage like this, can not cause the electric shock yet, so normal ground wire can not electrified.
Because the wires age or the contact is poor, the resistance of the grounding point is too high, or the grounding is not reasonable, and even the grounding wire is broken or has no grounding wire at all. The household has no ground wire, the zero line is used as the ground wire, the zero line enters the switch again at this time, or the zero line is broken, and the live wire can be directly connected with 220V high-voltage power from the side of the electric appliance.
In the first two years, there was a news that the switch of the water heater circuit in one's home was tripped and the person wants to take a bath and then call the electrician to repair. It is not thought that the person dies after taking a bath. It is known that neither 1P nor 2P circuit breakers can control the ground wire with or without a leakage protector. In other words, all the grounds in the home are on whether the switch is in a closed or open state. And all the ground wires are communicated with each other through the ground row in the distribution box. That is, as long as one ground wire is charged, all the ground wires in the home are charged.
Why will a person in the news get an electric shock? It is because the ground wire in his home is electrified, and the plug of the water heater is also plugged into the socket. The current is directly transmitted to the water heater through the ground wire, so that the electric shock during bathing is not surprising. Most people do not encounter this particular situation, but there are some situations that may be encountered. For example, the shell of the electric appliance is electrified, the electric appliance is burnt, and the like. Because the earth leakage protector cannot detect the current on the earth wire, the earth wire is electrified and cannot cause the tripping of the earth leakage protector. In describing the damage of the ground line electrification in detail by way of an example, recently, a report of Wuhan Yichang caused a strong reverberation in the local society. The accident reason is that the ground wire is electrified and the water heater has no defects after the work personnel of the technical supervision bureau check that the husband unfortunately electrocutes when bathing the electric water heater. The direct reason for electrification of the ground wire is that the live wire and the ground wire between the electricity meter boxes of the third floor and the fifth floor of the unit building are in short circuit, and the ground wire is in poor grounding, so that the ground wire is electrified and further accidents are caused.
There are many reasons for charging the ground. At present, the selection of the grounding points of alternating current and direct current of a large power grid, as household appliances are gradually increased, the actual electric load in a resident house far exceeds the original installation capacity and the safe current-carrying capacity of an incoming line, and a user does not timely go to a power supply department to handle capacity increasing and rectification procedures, so that a lead insulating layer is often burnt out, and a protective grounding wire is connected with a phase line to be electrified. In addition, the ground wire is charged by using inferior switch socket, private pull wire, irregular decoration and the like, the common leakage protector can not solve the problem of environmental leakage,
the metal casing has high conductivity, and when electric leakage occurs in the electric appliance, the casing is electrified, so that a wire needs to be connected to the casing to lead the casing to the ground. However, since the ground wire is not normally connected to the ground of the earth, a human body gets an electric shock, which undoubtedly brings danger to the life of the user.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a: aiming at the problems in the prior art, the ground wire electrification preventing protection device is provided, and the occurrence of personal electric shock and death accidents caused by electrification of the ground wire can be effectively prevented.
In order to realize the purpose, the utility model discloses a technical scheme be:
an earth-bound protection device comprising:
the input end of the first voltage relay is connected between a zero line and a ground wire of the protected circuit;
the input end of the second voltage relay is connected between the ground wire and the equal potential point of the protected circuit;
an intermediate element, an input end of which, a coil contact of the first voltage relay and a coil contact of the second voltage relay are connected in series and form a control loop; the intermediate element can output a control signal from the output end of the intermediate element after the control loop is conducted;
and the detection input end of the actuator is connected with the output end of the intermediate element, the output end of the actuator can open a protected circuit, and the power supply input end of the actuator, the contact point of the first voltage relay and the contact point of the second voltage relay are connected in series to a power supply circuit for supplying the actuator to operate.
Optionally, the method further comprises:
the input end of the third voltage relay is connected between the live wire and the ground wire of the protected circuit; and the coil contact of the third voltage relay is connected in series in the control loop.
Optionally, the contact point of the third voltage relay is connected in series in the power circuit of the actuator action.
Optionally, the method further comprises:
the current transformer is connected between a live wire and a zero line of the protected circuit;
the output end of the current transformer is connected to the current relay, the coil contact of the current relay is connected in series in the control loop, and the contact of the current relay is connected in series in the power circuit of the action of the executive element.
Optionally, the actuating element is a release or a circuit breaker.
Since the technical scheme is used, the beneficial effects of the utility model are that:
the utility model discloses a prevent ground wire electrification protection device, first voltage relay can use the zero line to detect whether there is the potential difference in ground wire and whether there is the electrified condition in ground wire for the reference, and second voltage relay can use the equipotential as the reference, further detects whether there is the potential difference between ground wire and the equipotential and obtains there being the electrically conductive condition of ground wire, accomplishes different potential difference through two voltage relay and detects, thereby judges that the ground wire is electrified, can realize the detection of multiple ground wire electrification condition; then the contact of the voltage relay is closed, and the action signal is driven to be sent out through the intermediate element, so that the executive component can control the breaker to break the power circuit including the ground wire in time, and the occurrence of personal electric shock and death accidents is prevented.
Drawings
Fig. 1 is a circuit diagram of a ground wire electrification preventing protection device according to embodiment 1 of the present invention;
FIG. 2 is a power supply circuit diagram of an actuator of embodiment 1;
fig. 3 is a circuit diagram of a ground wire electrification preventing protection device according to embodiment 4 of the present invention;
fig. 4 is a power supply circuit diagram of an actuator of embodiment 4.
Reference numerals: KV 1-third voltage relay, KV 2-first voltage relay, KV 3-second voltage relay and KA 1-current relay.
Detailed Description
Example 1:
referring to fig. 1-2, the earth-fault protection device of the present invention includes a first voltage relay KV2, a second voltage relay KV3, an intermediate element, and an actuator.
The input end of the first voltage relay KV2 is connected between a zero line and a ground wire of a protected circuit, the potential difference between the zero line and the ground wire can be detected, when the potential difference between the zero line and the ground wire is detected, and when the potential difference reaches a starting value, a coil of the first voltage relay KV2 cannot be electrified, and an auxiliary normally open contact cannot be closed; and if the potential difference between the zero line and the ground line is detected to be greater than the starting value, the coil of the first voltage relay KV2 is electrified, and the auxiliary normally open contact is closed.
The input end of the second voltage relay KV3 is connected between the ground wire and the equipotential point of the protected circuit, the potential difference between the ground wire and the equipotential point can be detected, when the potential difference between the equipotential point and the ground wire is detected, and when the potential difference reaches a starting value, the coil of the second voltage relay KV3 cannot be electrified, and the auxiliary normally open contact cannot be closed; and if the potential difference between the equipotential point and the ground is detected to be greater than the starting value, the coil of the second voltage relay KV3 is electrified, and the auxiliary normally open contact is closed.
The first voltage relay KV2 and the second voltage relay KV3 are both realized by the existing voltage relays, and the voltage relays with proper models can be selected according to different application occasions or different circuit power conditions.
The intermediate element, including the control signal output device composed of the comparator and the amplifier, can be realized by some conventional circuits in the prior art, and will not be described in detail herein. The input end of the intermediate element, the coil contact of the first voltage relay KV2 and the coil contact of the second voltage relay KV3 are connected in series to form a control loop, when the voltage relay reaches a starting value and the coil contact is electrified, the control loop is conducted, the intermediate element can obtain a control signal, and then the control signal capable of driving the actuating element is output after comparison and amplification.
The executive component comprises a circuit breaker and a release, the detection input end of the release is connected with the output end of the intermediate component, the output end of the release is connected with the circuit breaker of a protected circuit, the power input end of the release, the contact point of the first voltage relay KV2 and the contact point of the second voltage relay KV3 are connected in series into a power circuit for supplying the release to act, when the voltage relay reaches a starting value, the normally open contact is closed, the power circuit where the release is located can be conducted, and the release controls the circuit breaker to realize the disconnection of the protected circuit.
In this embodiment, the potential difference between the zero line and the ground line can be detected by the first voltage relay KV2, and by taking the zero line as a reference, when the ground line and the live line are short-circuited and the ground line is broken, the potential difference can be detected by the first voltage relay KV 2; the potential difference between the ground wire and the equal potential point can be detected through the second voltage relay KV3, so that the potential difference between the ground wire and the corresponding reference is judged in the same two different modes, the ground wire is finally judged to be electrified, and then the power failure of the protected circuit is controlled through the intermediate element and the execution element, so that the occurrence of personal electric shock and death accidents is prevented.
In this embodiment, the protection device for preventing the ground from being electrified further includes a third voltage relay KV1, an input end of the third voltage relay KV1 is connected between a live wire and a ground wire of the protected circuit; the coil contacts of the third voltage relay KV1 are connected in series in the control loop. The third voltage relay KV1 is only used as a working voltage detection element for detecting the working voltage of the house, and does not participate in the protection loop.
The working process of the earth wire live-line prevention protection device is as follows:
under the condition that a protected circuit works normally and the ground wire is not electrified, the first voltage relay KV2 detects that the voltages of the zero line and the ground wire are zero, the voltage detected by the second voltage relay KV3 is the voltage between the ground wire and the equipotential point, the voltages detected by the first voltage relay KV2 and the second voltage relay KV3 do not reach a starting value, and the contact points of the first voltage relay KV2 and the second voltage relay KV3 are not closed, so that the intermediate element has no output, the execution element does not act, the ground wire electrification preventing protection device keeps a connection state, and the power supply system keeps normal power supply.
When the earth wire is electrified or the phase wire is directly connected to the earth wire by mistake, because the voltage difference exists between the live wire, the zero wire and the equipotential point (the equipotential point of a house washing room, the equipotential point of a kitchen, the leakage point of a steel bar of a floor, a metal water pipe in the house and the like can be used as the equipotential point) and the earth wire, the first voltage relay KV2 detects the reverse potential difference relative to the earth wire of the system, the voltage is displayed as a negative value, the voltage detected by the second voltage relay KV3 is the voltage of the earth wire and the equipotential point, the numerical value is obviously larger, when the voltages detected by the first voltage relay KV2 and the second voltage relay KV3 reach the starting value, the contact point of the first voltage relay KV2 and the second voltage relay 3 is closed, an action signal is sent out, and the signal is processed and compared by intermediate elements (comprising an amplifier, a comparator, a fault memory, an acousto, when the setting constant value is reached, the tripper automatically trips the circuit breaker to cut off a fault circuit, so that connection of a live wire (phase wire), a zero wire and a ground wire of a power supply loop in a house is interrupted, and the purpose of completely isolating the live wire, the zero wire and the ground wire from the outside is achieved, thereby realizing a protection function.
Example 2:
the present embodiment is different from embodiment 1 in that the contact point of the third voltage relay KV1 of the earth-fault protection device is connected in series to the power circuit in which the actuator operates.
The device of the embodiment can adopt a new detection mode formed by the arbitrary combination of the first voltage relay KV2, the second voltage relay KV3 and the third relay, and realizes different protection functions.
Example 3:
the present embodiment is different from embodiment 1 in that the earth wire electrification preventing protection device does not include the third voltage relay KV1, and the earth wire electrification detection can be realized only by the first voltage relay KV2 and the second voltage relay KV 3.
Example 4:
referring to fig. 3 to 4, the ground wire electrification preventing protection device of the invention comprises a current transformer, a current relay KA1, a first voltage relay KV2, a second voltage relay KV3, an intermediate element and an actuator.
When the zero line and the ground wire are connected together inside the protected circuit, part of current returns from the ground through the ground, and after two currents flowing through the mutual inductor are offset, residual current exists, the residual current causes magnetic flux change, and induced electromotive force is generated in a secondary winding of the mutual inductor;
the current relay KA1 is connected to the output end of the current transformer, when the current detected by the current relay KA1 reaches a starting value, a coil of the current relay KA1 cannot be electrified, and an auxiliary normally open contact cannot be closed; if the detected current is larger than the starting value, the coil of the current relay KA1 is electrified, and the auxiliary normally open contact is closed.
The input end of the first voltage relay KV2 is connected between a zero line and a ground wire of a protected circuit, the potential difference between the zero line and the ground wire can be detected, when the potential difference between the zero line and the ground wire is detected, and when the potential difference reaches a starting value, a coil of the first voltage relay KV2 cannot be electrified, and an auxiliary normally open contact cannot be closed; and if the potential difference between the zero line and the ground line is detected to be greater than the starting value, the coil of the first voltage relay KV2 is electrified, and the auxiliary normally open contact is closed.
The input end of the second voltage relay KV3 is connected between the ground wire and the equipotential point of the protected circuit, the potential difference between the ground wire and the equipotential point can be detected, when the potential difference between the equipotential point and the ground wire is detected, and when the potential difference reaches a starting value, the coil of the second voltage relay KV3 cannot be electrified, and the auxiliary normally open contact cannot be closed; and if the potential difference between the equipotential point and the ground is detected to be greater than the starting value, the coil of the second voltage relay KV3 is electrified, and the auxiliary normally open contact is closed.
The current transformer, the current relay KA1, the first voltage relay KV2 and the second voltage relay KV3 are all realized by adopting the existing voltage relays, and the voltage relay or the current relay KA1 with proper models can be selected according to different application occasions or different circuit power conditions.
The intermediate element, including the control signal output device composed of the comparator and the amplifier, can be realized by some conventional circuits in the prior art, and will not be described in detail herein. The input end of the intermediate element, the coil contact of the first voltage relay KV2 and the coil contact of the second voltage relay KV3 are connected in series to form a control loop, when the voltage relay reaches a starting value and the coil contact is electrified, the control loop is conducted, the intermediate element can obtain a control signal, and then the control signal capable of driving the actuating element is output after comparison and amplification.
The executive component comprises a circuit breaker and a release, the detection input end of the release is connected with the output end of the intermediate component, the output end of the release is connected with the circuit breaker of a protected circuit, the power input end of the release, the contact point of the first voltage relay KV2 and the contact point of the second voltage relay KV3 are connected in series into a power circuit for supplying the release to act, when the voltage relay reaches a starting value, the normally open contact is closed, the power circuit where the release is located can be conducted, and the release controls the circuit breaker to realize the disconnection of the protected circuit.
The working process of the earth wire live-line prevention protection device is as follows:
under the normal condition that the protected circuit works normally and the zero line and the ground wire are not connected together, the currents flowing through the phase line L and the neutral line N are equal in magnitude and opposite in direction, and when the two currents pass through the mutual inductor, the magnetic fluxes generated in the iron core are also equal in magnitude and opposite in direction, and the magnetic fluxes are mutually offset. Because of no magnetic flux change, no induced electromotive force exists in the secondary winding of the mutual inductor, the current relay KA1 is not started, the voltage detection elements of the first voltage relay KV2 and the second voltage relay KV3 do not reach the starting value, the contacts of the current relay KA1, the first voltage relay KV2 and the second voltage relay KV3 are not closed, the intermediate element has no output, the execution element does not act, the ground wire electrification preventing protection device keeps a connection state, and the power supply system keeps normal power supply.
When the zero line and the ground line are connected together in the protected circuit, part of current returns from the ground line through the ground, after two currents flowing through the mutual inductor are offset, residual current exists, the residual current causes magnetic flux change, induced electromotive force is generated in a secondary winding of the mutual inductor, the detection value of a current relay KA1 is not zero any more and reaches a starting value, meanwhile, the detection value of a first voltage relay KV2 is zero, the detection value of a second voltage relay KV3 is not zero any more and reaches the starting value, coil contacts of the current relay KA1, the first voltage relay KV2 and the second voltage relay KV3 are closed, an action signal is sent, the signal is processed and compared through intermediate elements (including an amplifier, a comparator, fault memory, an acousto-optic alarm signal and the like), the circuit breaker is automatically tripped by a tripper, a fault circuit is cut off, and a live wire (phase wire) of a power supply loop in a house is enabled to be connected with, And the connection between the zero line and the ground wire and the outside is interrupted, and a professional is informed to search a fault point under the condition that the zero line and the ground wire are completely isolated from the outside, so that the protection function is realized.
Claims (5)
1. An earth-line-live-prevention protection device, comprising:
the input end of the first voltage relay is connected between a zero line and a ground wire of the protected circuit;
the input end of the second voltage relay is connected between the ground wire and the equal potential point of the protected circuit;
an intermediate element, an input end of which, a coil contact of the first voltage relay and a coil contact of the second voltage relay are connected in series and form a control loop; the intermediate element can output a control signal from the output end of the intermediate element after the control loop is conducted;
and the detection input end of the actuator is connected with the output end of the intermediate element, the output end of the actuator can open a protected circuit, and the power supply input end of the actuator, the contact point of the first voltage relay and the contact point of the second voltage relay are connected in series to a power supply circuit for supplying the actuator to operate.
2. The earth-fault protection device of claim 1, further comprising:
the input end of the third voltage relay is connected between the live wire and the ground wire of the protected circuit; and the coil contact of the third voltage relay is connected in series in the control loop.
3. The earth-fault protection device of claim 2, wherein the contact point of said third voltage relay is connected in series in a power circuit of said actuator action.
4. The earth-fault protection device of claim 1, further comprising:
the current transformer is connected between a live wire and a zero line of the protected circuit;
the output end of the current transformer is connected to the current relay, the coil contact of the current relay is connected in series in the control loop, and the contact of the current relay is connected in series in the power circuit of the action of the executive element.
5. The protection device of any one of claims 1-4, wherein the actuator is a trip unit or a circuit breaker.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922446159.7U CN211790722U (en) | 2019-12-30 | 2019-12-30 | Ground wire electrification preventing protection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922446159.7U CN211790722U (en) | 2019-12-30 | 2019-12-30 | Ground wire electrification preventing protection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211790722U true CN211790722U (en) | 2020-10-27 |
Family
ID=72977639
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201922446159.7U Active CN211790722U (en) | 2019-12-30 | 2019-12-30 | Ground wire electrification preventing protection device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211790722U (en) |
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2019
- 2019-12-30 CN CN201922446159.7U patent/CN211790722U/en active Active
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