In any commercial building, damage caused by an electrical surge is one of the key reasons for electrical equipment failure. These changes can originate internally or externally and thus a co-ordinated approach needs to be employed to protect against risk. What are some of the main causes of an electrical surge and what can be done to initiate protection?
What Causes a Surge?
An unexpected change or high-energy impulse in an electrical system is known as a "transient" or more commonly a surge. There are many different sources. The most obvious is the lightning strike, but surges can also originate during day-to-day utility switching activities, or unintentional failure of an electrical conductor when an overhead power line touches the ground. A surge can also come from within the building and be related to a malfunctioning photocopier, motor, air conditioning system, or elevator. Whenever this transient activity takes place a large dose of energy is delivered to one or more pieces of equipment on a circuit.
Protection Systems
Surge protection devices have to be correctly sized and properly installed if they are to provide the maximum safeguard. These devices interrupt a high current surge and divert it to the ground, avoiding the equipment in line. Consequently, the building itself must have an identifiable, well engineered low resistance grounding system, to which all devices can be connected. Certified electricians must be consulted in order to determine whether this is the case and rectify if needed.
Three Lines of Defence
Surge protection devices should be placed strategically throughout the building. The first place to start is where the utility company delivers the power to the facility. This is the point of protection against lightning strikes or utility system surges. The primary "entry" surge protector may not arrest the entire risk from the outside, so a secondary line of defense should be at all distribution panels. This is where power is diverted to various lines of equipment throughout the building. Thirdly, another line of protection involves placing a surge protector on each piece of crucial equipment. For example, plugging a computer into such a device before plugging it into the wall socket.
Rate Each Device Carefully
When you have this three-pronged approach in place, make sure that the surge protection device in each case is rated for its risk. Each one will be designed for specific circuits and voltage levels. Each one will also be configured to allow a certain burst, or "let-through" voltage in order to provide optimum levels of defence. Each device should therefore be checked to see just how much "let through" voltage is being delivered and, crucially, for how long. The piece of equipment being protected should then be checked to see that it, in turn, can accommodate this specific risk, without damage.
Finally, any such protection device should be placed as close to the corresponding equipment being protected, as feasible. Any cable lengths should be kept to a minimum and the device should have a visual indicator, so that regular inspections can quickly determine that everything is functioning.
For more information, check out companies such as Lollo & Allan Electrical.
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