ALARM SYSTEMS: THE STORMS WILL COME


One of the most unpredictable and often most detrimental threats to any security system is extreme weather conditions and in Johannesburg, we experience severe lightning storms, every summer.  An electric storm can wreak havoc with your gate motors, perimeter electric fence, external motion sensors, beams, backup batteries and internal alarm systems!

Lightning damage accounts for about 65% of all over-voltage damage to Electrical Distribution networks in South Africa.  Distant strikes, and even indirect strikes within 40 meters of a line, can induce over-voltages around 250 000 volts. 

How is this possible?
During an electric storm, there may be many lightning strikes that hit the ground directly, or connect with electricity poles, trees, television aerials etc.  There is an estimated 1 billion volts in one lighting strike, which generates a burst of heat 3 times hotter than the surface of the sun.

Due to the high rock content in the soil on most of the koppies throughout the West Rand (particularly in Muldersdrift), the ground flash strikes are among the highest in the country (known has Ground Flash Density).  Johannesburg experiences between 7 and 8 ground flash strikes per square-metre per year.  At 30 000 sqm, that’s a total of 210 000 – 240 000 ground flashes per year in Johannesburg alone!

Every time this happens the energy surge is incredible and it moves through the channel of least resistance, which could be your building’s circuitry, your gate or your electric fence – or all three.  The surge pushes through the thin wiring and melts it instantly, leaving a burnt, damaged mess and destroying everything along the path.

This is why a strike near your gate motor can destroy the motor, then travel through the wiring of the intercom system, destroying that, and if the wiring runs alongside your alarm cables, it can take that with it too.

What to do after a storm
  1. Check your gate motor.  If the circuitry has been damaged, it is possible for the gate to continue on the backup battery, but it will not charge.  It may be several days before the battery is depleted and you notice that there is a problem.  This will result in the battery and the mainboard needing replacement.  Check the the circuitry is not burnt and that the charge light is on.  If you are unsure of how to do this, contact us and we’ll help.
  2. Check perimetre fencing.  We have found that lighting will often strike fences directly.  During heavy storms, people tend to turn the alarm of the fence off due to the heavy rains triggering it.  If the fence is hit during this time, you may not realise that it is not working properly when you turn it back on.  Go to your energiser and check that all the zones are working as they should.
  3. Check and test your alarm system.  As with your gate, it’s possible that your alarm system could be running the backup battery, check that the power button is on and not flashing.  Also, whilst standing at the control pad, ask another person to walk around the building and check each sensor and ensure that each one is working properly.

Please remember that if your home, workshop, warehouse or offices have been severely hit by a storm that we are able to provide you with extra security guards whilst the damaged equipment is being replaced.  Contact us for a quotation and be ready.

With the stormy summer already upon us – be safe!  Contact us on (087) 943 7792 or email us if you need assistance with checking your system.

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