classic | mobile
Follow us on:
Follow us on Facebook  Share via Twitter  Share via LinkedIn

Hi-Tech Security Solutions Business Directory
Residential Estate Security Handbook 2018

All-live and kicking
September 2017, Perimeter Security, Alarms & Intruder Detection, Residential Estate (Industry)

Conventional electric fences have been around for a long time and remain a very effective means of providing a strong deterrent to criminal ingress. A conventional electric fence uses alternating wires for live and earth potential. A positive pulse is injected onto the live wire at roughly 1 Hz. (one pulse per second).

If anyone touches between a live and earth wire, or touches a live wire whilst standing on the ground, he/she will receive a non-lethal but unpleasant electrical shock. Touching an earth wire will have little or no effect. So roughly only half of the fence’s wires ‘bite.’

The live wires may be in a series or loop configuration, which can provide immediate notification of a live wire being cut anywhere along the zone or sector. The earth wires are almost always connected in parallel to maintain a good continuous reference voltage for the live wire. Cutting an earth wire will have no effect provided it does not come in contact with another live wire.

Some older fences may still have the live wires in parallel too, a carry-over from agricultural fences, or a ‘cheat’ to make the fence appear to be running at full voltage, while masking some poor installation or maintenance shortcomings. As soon as any wires are placed in parallel, one loses the benefit of cut protection monitoring as the electrical path now has several branches to use and simply diverts to another available path.

A relatively new concept is to deploy an all-live wire configuration. Here the previously parallel connected earth wires are reconfigured to a second live circuit or loop. Two simultaneous, but oppositely charged pulses are injected onto the two adjacent circuits. A positive pulse onto the old ‘live’ circuit and a negative pulse onto the newly reconfigured earth wire circuit.

The net result is a shock if you touch between any two adjacent wires, regardless if you are earthed or not, or a half voltage shock if you are earthed. The net results are: an all-live wire fence, cut protection monitoring on every wire, reduced and equal voltage across all insulators with respect to earth and a fence which is far less vulnerable to manipulation.

This concept also works particularly well on wall-top installations where an assailant will not necessarily be in contact with earth while attempting to challenge a fence. The new SANS regulation requirement of regular earth spikes takes care of providing a continuous reference voltage around the perimeter.

Elf Rentals started converting some of its premier clients to the all-live wire fence configuration in 2015 to afford these residential estates a new and improved level of protection. The result has been a transformation of what were high-maintenance sites to very stable and very secure perimeter fences, where both client and service provider are reaping the rewards.

For more information contact Elf Rentals, +27 (0)41 368 3701,

  Share via Twitter   Share via LinkedIn      

Further reading:

  • Border security: Technology or barriers?
    November 2018, Technews Publishing, This Week's Editor's Pick, Perimeter Security, Alarms & Intruder Detection, Government and Parastatal (Industry)
    While it is important to provide a visible as well as a covert patrolling presence on borders as well as points of entry from other countries, this needs to be supplemented with technology.
  • Centurion hosts second Access Automation Expo
    November 2018, Centurion Systems, News, Access Control & Identity Management, Perimeter Security, Alarms & Intruder Detection
    Centurion Systems has taken its Access Automation Expo national, visiting Durban and Cape Town for the latest events.
  • Four-line menu-driven LCD keypad
    November 2018, Stafix, Perimeter Security, Alarms & Intruder Detection, Products
    The latest four-line JVA keypad is menu driven, allowing the installer to program the energiser simply by interacting with the menu system.
  • Low-voltage electric fence monitor
    November 2018, Stafix, Perimeter Security, Alarms & Intruder Detection, Products
    The ZLM1 and ZLM4 are low voltage 1 -and 4-zone electric fence energisers that keep voltages are under 50 V.
  • Android keypad with mimic display
    November 2018, Stafix, Perimeter Security, Alarms & Intruder Detection, Products
    The JVA Touch Screen Keypad is manufactured specifically for the control and management of the full range of JVA Z-Range energisers and monitors.
  • Hikvision launches Security Radar
    November 2018, Hikvision South Africa, Perimeter Security, Alarms & Intruder Detection, Access Control & Identity Management, Integrated Solutions
    Hikvision has launched its Security Radar intrusion detection solution to pinpoint the location and motion trail of up to 32 potential intruders per radar.
  • Letter to the editor
    October 2018, Technews Publishing, Associations, Perimeter Security, Alarms & Intruder Detection
    We refer to an article published in your August 2018 edition, namely “The alarming disadvantages of home security systems”, written by Meraj Hoda, vice president of Ring Inc. The content of this article ...
  • Breaking par for security at ­Woodhill
    October 2018, Technews Publishing, This Week's Editor's Pick, Integrated Solutions, Security Services & Risk Management, Residential Estate (Industry)
    Xone Integrated Security was selected to provide a full security service to the luxurious Woodhill ­residential estate
  • There’s more than one approach to video verification
    October 2018, Technews Publishing, Perimeter Security, Alarms & Intruder Detection, CCTV, Surveillance & Remote Monitoring
    It is no secret that false alarms are one of the biggest headaches presented by electronic security systems, but video verification is emerging as an efficient solution.
  • iotega home automation panel
    October 2018, Elvey Security Technologies , This Week's Editor's Pick, Perimeter Security, Alarms & Intruder Detection, IT infrastructure, Products
    The DSC iotega WS900x wireless home automation panel intelligently activates homes and businesses, based on events, schedules and other triggers.
  • Aura Ai-2
    October 2018, Ava Group, Products, Perimeter Security, Alarms & Intruder Detection
    Aura Ai-2 is the next generation controller from FFT, offering perimeter intrusion detection solutions. It can effectively monitor optical lengths of up to 110 km per controller for buried, and 80 km for fence installations.
  • Integrated alarm and video
    October 2018, Hikvision South Africa, This Week's Editor's Pick, CCTV, Surveillance & Remote Monitoring, Perimeter Security, Alarms & Intruder Detection
    Hikvision has released news of the AXHub intruder alarm system, the wireless system caters for any residential and small commercial applications by connecting security and video on one platform.

Technews Publishing (Pty) Ltd
1st Floor, Stabilitas House
265 Kent Ave, Randburg, 2194
South Africa
Publications by Technews
Dataweek Electronics & Communications Technology
Electronic Buyers Guide (EBG)

Hi-Tech Security Solutions
Hi-Tech Security Business Directory (HSBD)

Motion Control in Southern Africa
Motion Control Buyers’ Guide (MCBG)

South African Instrumentation & Control
South African Instrumentation & Control Buyers’ Guide (IBG)
Terms & conditions of use, including privacy policy
PAIA Manual
    Mobile | Classic

Copyright © Technews Publishing (Pty) Ltd. All rights reserved.