Electronic fence system principle and installation precautions

The electronic fence system has a strong blocking and deterrent effect, a smart alarm function with a very low false alarm rate, and an alarm interface, which can be linked with other security systems to improve the security level of the system. The following describes the principle of the electronic fence and its installation precautions.

The concept of intelligent perimeter security pulse electronic fence

"Blocking first, supplementing alarming" is a dual function of deterrence and alarm. It has good security, low false alarm rate, strong deterrence, high reliability, wide adaptability, no blind spots, no dead ends, and no loopholes.

What are the main functions of the electronic fence system?

1. It has a complete and well-defined electronic fence with strong blocking and deterrent effects.

2. It has an intelligent alarm function with a very low false alarm rate.

3. Equipped with an alarm interface, which can be linked with other security systems to improve the security level of the system.

What are the main components of the electronic fence system?

The pulse electronic fence system is mainly composed of two parts: the controller which integrates pulse emission, alarm and integration, and the electronic fence. Usually, the electronic fence is installed outdoors, along the original fence (such as brick wall, concrete wall or iron fence), and the detector is connected to the near end.

The advantages of the pulse electronic fence system to the contractor:

1. For the design of perimeter system, after using the pulse electronic fence system, the setting of perimeter monitoring equipment can be cancelled, which reduces the owner's expenditure and makes it easy for the engineering company to win the bid in the bidding process.

2. The pulse electronic fence system introduces a new concept of "block-based" intelligent prevention, which has made a fundamental breakthrough in technology and function, and provides a technical competitive advantage for the winning standard, which is easy to be accepted by users.

3. The system has a reliable structure, a long service life, and a reduced use cost (average cost and maintenance cost per year), which is beneficial to both the contractor and the owner.

4. The pulse electronic fence system is easy to install and debug, can reduce construction costs, is stable and reliable, has a long service life, and has a low false alarm rate. Basically, after-sales service is not required, so the cost is greatly reduced.

How is the blocking function of the pulse electronic fence system implemented?

Traditional infrared radiation systems, leaky cables or microwave systems only have an alarm function and no blocking function. Intruders can often cross the cordon without stopping. In other words, when someone invades, it may have entered the security area before the system alarms. This complicates event processing.

The pulse electronic fence has set up an electronic fence around the defense zone. If someone attempts to invade, first see the "Caution Electronic Fence" warning sign hanging on the fence, giving a psychological sense of deterrence. If an attempt is made to cross over when the fence is touched, an electric shock is given to make it shrink away, and dare not touch it again. If it climbs forcibly, the system issues an alarm. Furthermore, the electronic fence uses a flexible wire hanging rod. When the intruder attempts to cross, the flexible fence does not give support, making the intruder unable to cross. This is the effective blocking function of the electronic fence.

Does the electric pulse of the pulse electronic fence system guarantee personal safety?

Although the pulse voltage of the pulse electronic fence system reaches 6000-10000V, the repetition frequency of the pulse is extremely low, only once per second. The duration of the pulse is ≤ 0.1 second. The large pulse energy is 5 Joules, and the large pulse energy is 2.5 mK. It can be seen that its energy is very small, it will not hurt people, only give the intruder a more uncomfortable warning, shake its ability and motivation to climb the fence, and achieve the purpose of safe blocking.

How is the alarm function of the pulse electronic fence system implemented?

In the traditional infrared radio alarm system, an alarm will occur whenever someone or something passes the cordon. When animals such as cats or dogs pass by, they will still call the police. Therefore, what should not be reported is also reported. In case of bad weather such as heavy rain and dense fog, the system fails, and the report will not alarm.

The new pulse electronic fence system has the function of distinguishing accidental touch and forced intrusion. If someone touches the fence carelessly, or other objects (such as branches) touch the fence instantly, because this is not a real invasion, the system has the ability to discriminate Call the police. Only when the intruder forcibly invades and climbs the electronic fence, causing the system to be disconnected (open circuit) or continuously touching the line (short circuit), an alarm will be issued. Therefore, the alarm of the pulse electronic fence system has an intelligent function, the report will report, and the report will not report. The false alarm rate is extremely low.

Precautions for the use and installation of electronic fences

The installation method of the electronic fence is directly related to whether it is used normally, but also related to the normal use of other electrical equipment, so it is very important. Before installing the electronic fence, the following must be noted:

1. In order to reduce the risk of electric shock, service personnel are requested not to get warning signs while working on electronic fences, and to prevent other personnel from moving warning signs at will.

2. Do not use damaged wires, especially wires with thorns, to prevent injury to humans and animals

3. When charging maintenance-free lead-acid batteries or other dry batteries, please remove the batteries before recharging. It is strictly forbidden to charge the batteries directly on the electronic fence, which will cause damage to the battery and the electronic fence host.

4. The two sets of electronic fence hosts cannot be powered to the same set of fences. This will cause damage to the host due to the inconsistency of high-voltage pulses sent by the electronic fence hosts, and also lead to casualties.

5. It is strictly forbidden to modify the internal circuit of the electronic fence host or replace the electronic components by yourself, which may easily lead to machine failure or harm to human life.

6. It is strictly forbidden to contact or approach the electronic fence in thunderstorm weather to prevent the occurrence of lightning strike accidents. For all electronic fences, regardless of whether lightning protection or not, this article must be strictly prohibited.

7. Inform all the personnel who manage the fence how to cut off the output of the electronic fence host to prevent the emergence of an emergency, and place an operation guide on how to cut off the electronic fence host in a conspicuous place on the electronic fence host

8. It is strictly forbidden to use the adapter from city power to 12V DC without authorization to supply power to the host, which is easy to cause the output voltage of the host to be too high due to the failure of the adapter itself, and insulation failures occur.

9. After the installation, please confirm whether the host is working properly. The power-on lamp of the host indicates that it has been working normally. Please rest assured to use it. It is strictly forbidden to touch the fence after starting up.

10. It is strictly forbidden for infants and young children, pregnant women to touch the electronic fence, regardless of whether there are any conditions, such personnel must be prevented from approaching the electronic fence, otherwise such equipment cannot be installed

11. It is necessary to prevent visible warning signs next to the electronic fence host, and place warning signs at the fence.

12. The grounding must be reliable and compact, and the grounding system must be far away from the living area.

13. It is strictly forbidden to dismantle the electronic fence host without permission, and it is strictly forbidden to replace the components without permission, and contact the supplier in time if problems occur.

Summary of technical issues of electronic fences

A. The influence of external interference on the electronic fence

There are two kinds of small animals,

One is birds. Since the birds fall on the electronic fence in a suspended state, it will not cause the fence voltage to leak, so it will not alarm;

Another kind of walking beast, when the claw of the small animal touches the fence, due to the voltage difference to the ground, the electric shock will be caused to the small animal, and the small animal will run away because of the pain. Due to the alarm delay setting on the electronic fence pulse host Generally, the alarm will be triggered after a delay of 3 seconds. This situation will be filtered to prevent false alarms. This alarm delay parameter can be set, from instant alarm to 5 seconds delay alarm, which can be flexibly selected.

The normal operating voltage on the fence is 700-900V or 4000-8000V, and the factory default value of the alarm voltage detected by the pulse host is 750V or 5000V. When the perimeter fence is affected by the outside world, it causes voltage leakage and leaks below the 5000V alarm line Alarm output will be generated at the time; if the leakage is above 5000V, it will not alarm. Therefore, general small animals, green trees and other external disturbances will not cause false alarms when the alarm line is 5000V.

The effect of weather on the electronic fence. If due to weather conditions, especially extreme weather conditions, the alarm voltage can be adjusted to reduce false alarms.

B. Security of electronic fence

1. Technical perspective

Although the voltage of the electronic fence is between 5000V and 8000V, it has a strong deterrent to intruders. However, whether the damage to the intruder is critical depends on the current and the pulse power. Generally speaking, the single pulse power of the traditional high-voltage power grid for prison is 40 milli-coulombs, while the single pulse power of the electronic fence is only 2.5 milli-coulombs. The difference is almost 20 Times.

At the same time, the pulse current of the electronic fence has a peak value of 300 milliamperes in a one-second pulse period and a duration of only 1.5 milliseconds, which is very short. The current of the traditional high-voltage power grid is above 10 amps. So as far as a single pulse is concerned, the energy of the electronic fence can only achieve a sense of deterrence, not harm, and is safe. At the same time, if someone crawls on the electronic fence due to excessive tension, it will cause a short circuit of the electronic fence. At this time, if the traditional high-voltage power grid will stick to the intruder and cause a continuous blow to the intruder, the electronic fence will be within 1 second. An alarm is issued inside, and the voltage of the electronic fence will become 0, the pulse host will stop the voltage output, and will not cause a continuous blow to the intruder.

At the same time, the electronic pulse detector has two output modes of high voltage and low voltage, high voltage has electric shock sensation, low voltage has no electric shock deterrence, and both modes can alarm. If you are worried about high-pressure mode causing accidental injury, you can choose low-pressure mode, which is safe at this time.

2. How to link with the alarm system

When the pulse host alarms, the output is a pure binary on-off signal, which can be directly connected to various alarm hosts in the security industry (such as CK236, CK238, VISTA120, etc.) to achieve alarm linkage, and can also be a video monitoring system, 110 alarm, etc. Linkage with other security alarm systems.

The electronic fence anti-theft system has supporting multi-channel alarm equipment. Through the supporting equipment, a complete perimeter security system can be formed to meet the needs of different users and different security levels.

3. Wiring technology summary

â‘  A defense zone is a serial loop from the transmitting part to the front fence, and then to the receiving part, which must be connected in series, not in parallel, or branched.

â‘¡ When the conductor crosses the intersection, it must be connected with a high-voltage resistant conductor to avoid causing conduction or short circuit.

â‘¢ There must be sufficient space between the wire and the wire, and between the wire and the metal conductor.

â‘£ The system should have a good grounding system, the grounding point should be separated from the grounding point of the power line, and the grounding resistance should be less than 4 ohms.

⑤ There are two ways to connect the alloy wires. One is to connect by self winding method, the joint should be wound tightly, no less than five turns. The second is to connect with a wire connector, first insert the two wire ends to be connected into the connector, and then use pliers to press the wire tightly into the connector. Since the crimping is not necessarily tight and may be loose, the two ends must be wound on their own wires separately. The winding must be close to the alloy wire being wound, and the number of windings should not be less than 5 turns.

â‘¥ Avoid different metal wires. Because metals of different properties are connected together, there will be electrochemical reactions that cause corrosion, so the material of the inner core of the high-voltage insulated wire and the alloy wire must be the same material.

4. Installation skills in special places

A. How to install the electronic fence door

In the electronic fence system, the door is the weak link, because the door is an object that runs frequently. The design of the door should pay attention to the electrical contact between the wire and the door frame itself, and it should be designed not to affect the movement of the door hinge. B. How to wire the underground installation

When the electronic fence is to be wired underground, a high-voltage insulated wire with a rated voltage of 15KV should be selected and penetrated into the insulation threading pipe. Among them, the lead wire with positive pole and the lead wire with negative pole respectively penetrate into different insulating tubes. High-voltage insulated wires should not have connectors as much as possible, and connectors of high-voltage insulated wires should be avoided as much as possible. Because the ground is usually humid, it is difficult to maintain good insulation strength at the joints. If the joint cannot be avoided, the insulation of the joint part should be strengthened. For example, use silicone rubber to encapsulate, or turn the joint above the ground.

5. Distinguish between electronic fence failure alarm and intrusion alarm

â‘  When the main power supply is powered off, the pulse host automatically switches to the working state of the battery. At this time, there will be a fault alarm output, and there will be no intrusion alarm; if there is a protective relay on the alarm output, the security personnel will be required to reset the pulse on site within 48 hours. The host (that is, disarm and re-arm), after reset, the fault alarm is automatically cleared.

â‘¡When the main power supply will resume power supply and the quality of the battery is intact (within one year of use), the system will switch to the main power supply state and the battery will be automatically charged. At this time, there will be no fault alarm and intrusion alarm.

â‘¢The independent working time of the pulse host battery is about 4 hours, and the battery power consumption exceeds 4 hours (the battery voltage is lower than 11V at this time). If the main power supply is not restored at this time, the entire system will be paralyzed due to power failure, and there will be a fault alarm And intrusion alarm output.

â‘£The general life of the battery is about 1 year, and it will be scrapped after more than one year.

⑤ When the pulse host is in the disarmed state, the battery in the host is normally powered. At this time, only the chip in the pulse host consumes power. The power consumption is negligible compared to the storage capacity of the 4AH12V battery.

â‘¥ When the pulse host is in a power-off state, that is, there is no battery power supply or main power supply in the host, then the relay in the pulse host is closed, that is, there is an intrusion alarm and fault output.