CENTURION vs. Nature

Mother Nature is a notoriously fickle – and at times downright ruthless – dame. While she may occasionally do something whimsical like giving us a monkey’s wedding, there are also times that it’s quite evident that she’s had a fight with her boyfriend or something. This year especially was fraught with meteorological curve balls including, but not limited to, tornadoes. Freaking. Tornadoes.

It’s also starting to become pretty clear that Al Gore was onto something with the whole global warming thing. According to NASA’s Goddard Institute for Space Studies, Earth’s overall temperature has increased by 0.8°C since 1880. While this may seem insignificant, the effects are dramatic and far-reaching and, regrettably, climate change is showing no signs of slowing down.

Earth's overall temperature has increased by 0.8 degrees centigrade since 1880

While there’s not too much that we can do about the weather, we can set your mind at ease by telling you that CENTURION products have been designed to handle very extreme environmental conditions.

According to senior electrical engineer Tony Baia, reliability as a design philosophy and something to be sought with relentless fervour has been ingrained in CENTURION’s DNA since the very beginning.

CENTURION senior electrical engineer, Tony Baia

“From its inception,” begins Tony “Centurion Systems’ founding fathers and design engineers understood that, to ensure the reliability of its now-famous D5 [sliding gate motor] and other electronic products, they had to tame one of nature’s most awesome and powerful phenomena: lightning”.

Lightning has for long been the bugbear of electrical appliances, the lure of so much sweet, conductive metal in one spot simply too much for heaven’s own electricity to withstand. It’s a siren song as old as time, but the tune is no easier to hum along to. Every year, insurance companies pay out millions in lightning-related claims, and some firms do not compensate for lightning damage as it’s seen as a vis major.

“With this in mind,” continues Tony “the design engineers approached the CSIR [Council for Scientific and Industrial Research] and other institutions who had the equipment and knowledge to tame lightning.

“A cost-effective and highly efficient circuit was designed that has remained with Centurion Systems to this very day, ensuring that our control cards continue to function when other equipment has failed”.

Tony provides a detailed description of the kind of technology that goes into such a sophisticated and robust piece of equipment.

“CENTURION uses a layered approach to protect against lightning; all inputs exposed to the outside world are protected by multiple components”.

Layer 1

Right up front is a high-power resistor that absorbs and slows down the lightning surge.

This is followed by a Zener (analogous to a clamp) that prevents the lightning-induced voltage from going above levels that are harmful to the rest of the electronic components on the PC board.

Layer 2

The lightning-induced voltage sometimes climbs much faster than the Zener is able to respond; to further protect the sensitive electronic components, another capacitor and resistor are used to slow down the rising voltage allowing the Zener time to respond and clamp the harmful voltages.

Layer 3

The TRG [trigger] input is the one that is most exposed to lightning surges due to it having the longest connection length – this connection could run from the gate motor all the way to the indoor intercom system.

To ensure that this input has even more protection against lightning surges, a gas arrestor is placed in front of the high-power resistor to further absorb the energy of the lightning surge.

Level 4

To protect against lightning surges, the energy that is being absorbed by the abovementioned layers needs to find a path to earth or ground; to achieve this, another gas arrestor connects to the mains power supply earth.

Level 5

CENTURION power supplies like the CP84SM have an earth tab that connects to an earth spike, allowing the lightning surge energy to find a very quick and easy path to earth, thereby avoiding damaging the sensitive electronic components on the control card.

Layer 6

The power supplies like the CP84SM also have protection against lightning surges coming down the municipal power lines. These take the form of metal oxide varistors, or MOVs. MOVs limit the voltage supplied to an electrical device by either blocking or short-circuiting to ground any unwanted voltages that are above a safe threshold.

“Lastly,” Tony concludes “it must be remembered that, if the lightning surge is too powerful or too close to the gate motor then something has to give. That is when most of the components referred to above will be damaged, sometimes leading to unseen damage of other components on the PCB”.

In addition to superior lightning protection, CENTURION operators boast a number of sophisticated design features intended to moderate Ma Nature’s onslaughts. These include:

• · Insect-ingress protection – insects are a big problem throughout continental Africa
• High water-level lines for reasonably good immunity to flooding
• Black-out and brown-out failure protection – CENTURION’s products are purpose-built to address these classically Third World-type infrastructural problems