Surge Protection Devices
Surge protection equipment is available from private suppliers. However, BC Hydro does not supply nor will it install this equipment on customer meters.
Although you may be unfamiliar with the term power quality (PQ), you are likely aware of the consequences of PQ problems. Losing critical computer data to a blackout, or experiencing damage to process or medical equipment due to a lightning strike are just two examples of how these problems can affect your business. Technically speaking, power quality refers to the degree to which electricity is free of disturbances that can cause electricity-consuming devices to malfunction or fail. PQ problems can affect many types of equipment in your facility, but especially electronic equipment that's dependent on microprocessors. Computers, network servers, energy management systems, machinery, and food-processing and medical equipment could be damaged or fail prematurely if they are not protected from harmful voltage changes or related disturbances.
Electronic devices function properly as long as the voltage delivered to your facility falls within a consistent range. Swells, transients, sags and momentary interruptions occur when the voltage fluctuates outside this normal range.
Utilities strive to provide highly reliable and consistent electric power, but it's impossible for utilities to maintain perfectly constant voltage 100% of the time. In the course of normal utility operations, voltage will inevitably fluctuate as loads come onto or leave the power system or the utility switches among various sources of electricity supply.
PQ events also occur for reasons that have nothing to do with your utility. Lightning strikes can cause major power disturbances. More subtle PQ problems often originate within the walls of your building, and can be traced to the starting and stopping of refrigerator or air-conditioner motors, circuit overloads, or grounding and wiring problems. Experts estimate that up to 80% of transients and swells originate within the facilities that they affect.
Why is this important?
Depending on the size of the voltage fluctuation, PQ problems can vary in severity, ranging from brief malfunctions to immediate equipment failure. Small fluctuations may not cause any problems initially, but, if left unchecked, these events can lead to equipment degradation over time. If a loss of data or productive time would have a significant impact on your business, or if the cost of replacing failed electronic equipment is high, you need to protect your company against PQ-related damage.
What are the options?
There are two major ways to protect your equipment from voltage transients. First, you can provide protection at the point of entry—at your electrical panel or meter. Second, you can install protection at the point of use, where sensitive pieces of equipment connect to electrical outlets. A combination of point-of-entry and point-of-use devices will provide the greatest level of protection.
Point-of-entry protection
Panel-mount surge suppressors can be installed in or adjacent to your electrical panel(s) to provide protection throughout your facility. These panel-mount or hard-wired surge suppressors protect against transients that come through utility power lines (Figure 1). In addition, they can prevent transients that originate on one of your facility's electrical circuits from affecting other circuits.
 |
Figure 1: Panel-mount suppressors Courtesy: Danaher Power Solutions |
Another way to provide whole-facility protection is to use a meter-based Surge Protection Device (SPD). Note, however, that these devices can be installed only by a qualified expert.
Point of use: Plug-in surge suppressors
Plug-in surge suppressors provide affordable but somewhat limited protection for sensitive equipment. Often designed as power strips with multiple outlets, they protect only the devices that are plugged into them (Figure 2). Other plug-in surge protectors fit over wall outlets. Some models include jacks for telephone and cable-television lines.
 |
Figure 2: Plug-in surge suppressors Courtesy: Tripp Lite |
Can they save energy?
A small number of surge protection devices manufacturers and vendors continue to claim that their devices can save users substantial amounts of energy. These claims persist despite the fact that they were thoroughly refuted decades ago.
For a look at these energy-saving claims, please refer to the bchydro.com article Beware of claims about 'power-saving' devices.
Copyright © 2008 E Source Companies LLC
Last Modified: May 9, 2009
