The International Standard IEC60335-2-76 mandates that for dry energy-limited electronic fences, under specified test conditions, the energy/pulse on the standard angular load of 5000 ohms should not exceed 5 joules. However, there is no limit set for the output pulse energy of the electronic fence. In fact, the pulse output energy of high-end models available on the international market far exceeds 5.0J, reaching up to 42J! Yet, the technical difficulty of such models is significant, with only a few international companies possessing the design and manufacturing capabilities. Some agencies that publicly promote this erroneous energy indicator clearly lack a professional foundation in electronic fence technology, have a limited understanding of the international standard system and global market products, and misinterpret and misrepresent the facts.
Market Misinformation – Safety Speak:
In fact, the international leading standard IEC60335-2-76 equates humans and animals to a 5000 standard load, and determines the safety limit to be 5 based on the IEC60479 series standards (effect of current on the human body and livestock). Therefore, the lethal pulse energy corresponding to the human body is as early as 271. Consequently, enclosures that comply with the IEC60335-2-76 limits are subject to a sub-enclosure, but for security sub-enclosures, the output energy directly determines the system's protective functions and alarm accuracy.
Day 1 of 3J's deployment: electric shock sensation only causes numbness, insufficient to deter illegal tree crossings; occasional false alarms; the system's effective function is for detection and psychological deterrence.
5 Joules: The shock feels like a needle prick, serving as a warning to stop illegal climbing, effectively reducing false alarms. The system's effective function includes shock deterrence, detection alarms, and psychological intimidation (the ideal level for preventive measures).
Shanghai Local Standard -- Hu Gong Ji Fang (2008) No. 0013, requires that the length of each perimeter defense zone does not exceed 70 meters.
The objective may be to treat electronic fences as detection alarm systems, utilizing their unique deterrent functions and relatively reliable alarm technologies to simply replace infrared beam detection alarms, while continuing to adhere to the technical specifications of infrared beam detection. In fact, no international or other national standards have similar requirements. On the contrary, the international engineering application specifications emphasize first and foremost the electric shock isolation capabilities of electronic fences, followed by reliable detection alarm technologies. Generally, security projects select electronic fences with an output energy level of 5J, while high-security projects may opt for more advanced levels of electronic fences.
Therefore, there is no concept of short-range protection zones like infrared beam crossing in the design and application of electronic fence projects in developed countries. Instead, the driving distance of the electronic fence is determined based on the requirement that the voltage attenuation at the output and feedback ends of the electronic fence does not exceed 20%. Generally, the driving distance of the electronic fence host is proportional to the output energy and inversely proportional to the number of lines and the resistivity of the fence wire.
