Surge Protection

Transient overvoltages are short duration, high magnitude voltages peaks with fast rising edges also known as surges. Often described as a spike transient voltages can reach up to 6000v on a low-voltage consumer network with no more than a millisecond duration. Lightning strikes are the most common source of extreme transient overvoltage where total outage of an unprotected system can occur with damage to cabling insulation through flashover potentially resulting an electric shock and loss of life. However electrical and electronic equipment is also continually stressed by hundreds of transients that occur everyday on the power supply network through switching operations of inductive loads such as air-conditioning units, lift motors and transformers. Switching transients may also occur as a result of interrupting short-circuits currents (such as fuses blowing). Although switching transients are of a lower magnitude than lightning transients they occur more frequently and equipment failures unexpectedly occur often after a time delay degradation of electronic components within the equipment is accelerated due to the continual stress caused by these switching transients. Transient overvoltages whether caused by lightning or by electrical switching have similar effects: disruption (e.g. data loss, RCD tripping), degradation (reduced equipment lifespan), damage (outright equipment failure, particularly concerning for essential services such as fire and security alarm systems) and downtime – the biggest cost to any business such as lost productivity and product spoilage, staff overtime, delays to customers and sales lost to competitors.