Surge protection needs a rethink
ELECTRICAL & ELECTRONICS SMARTER SURGE DEFENCE
CP AUTOMATION
Surge protection needs a rethink
Electrical maintenance is often focused on mechanical equipment in industrial facilities – motors, bearings and conveyors – but the risks posed to power electronics can be just as serious. Where there is microprocessor-based equipment, transient over-voltages can damage performance long before outright failures are noticeable, explains John Mitchell, global sales and marketing director at CP Automation.
The need for surge protection is clear: a voltage spike typically lasts one to 30 microseconds and can reach over 1,000 volts. Meanwhile, longer-term voltage surges can last for seconds, minutes or even hours. In some cases, this can lead to complete equipment failure, forcing production to stop.
Left unattended, transient surges lead to false zero crossing of the sine wave— the instantaneous point at which no voltage is present. Electrical devices can be falsely triggered because of fast-changing signals caused by these transients.
The limitations Modern industrial electronics run on lower voltages internally, making them far more sensitive to transient over-voltages than in the past. While lightning strikes are an obvious threat, most damaging spikes are generated within the facility by equipment such as PLCs, UPSs and variable speed drives. These low-level events can cause false triggering, software errors and premature component failure.
Traditional surge protection devices( SPDs), such as surge arresters, only
The need for surge protection is clear: a voltage spike typically lasts one to 30 microseconds and can reach over 1,000 volts.
activate once the voltage passes a certain threshold, allowing harmful energy to pass through— known as let-through voltage. Many of these SPDs are also single-use, meaning that once they’ ve operated, protection is lost.
The future Newer transient frequency attenuation devices( TFADs), such as SineTamer, use a different approach. Operating in parallel rather than inline, these monitor all 360 degrees of the sine wave, detecting and reaction to rapid changes before the energy builds up to damaging levels.
As a result, this can reduce letthrough volage by up to 90 per cent while protecting vital assets from both external and internallygenerated events. Unlike many SPDs, SineTamer can withstand multiple surges without failing, ensuring continuous protection beyond the first incident. This resilience is particularly important in environments where transients are frequent but not always dramatic enough to trigger a shutdown.
Transient over-voltages remain a risk for industrial facilities – and therefore, it’ s important to select an effective SPD. Rather than relying on traditional SPDs, like surge arrestors, facilities now have the choice of alternatives that can take multiple hits and minimise let-through voltage.
To find out more, please visit www. cpaltd. net / ac-input-products / surge-supressors / surge-protective-devices /
58 PECM Issue 76