How to Protect Electronics from an Aging Power Grid
A recent federal initiative to improve America's aging infrastructure offers a glimmer of hope for a national electrical grid that a University of Pennsylvania lecturer once described as "a third-world electricity system."1 More than 3,100 electrical energy providers serve nearly 150 million customers in the contiguous 48 states.2 The grid switching required to meet shifts in demand makes the entire system vulnerable to electrical power disruptions, surges, and spikes.
Because much of the electrical distribution system is outdoors, environmental disruptions also play a role. These include direct and indirect lightning activity, wind-induced contacts with trees and vegetation, and downed poles from car accidents or rockslides. For example, in 2003, an unexpected contact between a distribution line and a tree resulted in a total blackout of Southeastern Canada and eight Northeastern states.3 Fortunately most disruptions aren't nearly as severe.
New strains on old system
While the grid is reliable, its age can't be ignored. Much of the current system is decades old. Expensive, high voltage power transformers are approaching end of life. Renewable energy sources, such as wind or solar power, are inherently intermittent and put additional stress on the grid. And the emergence of ‘Smart Grid' technologies that promise to improve older electro-mechanical switches are susceptible to cyberattacks and disruptions.
Effects of electrical disruptions
Electrical outages, surges and spikes can damage any type of unprotected electrical cabling, including power, phone, and data/cable/internet systems. Commercial office buildings contain network communication systems and sensitive devices that store important data. A major spike can cause catastrophic damage, even fire. More common, however, are lower level spikes that slowly degrade electrical components, shortening their lifespan and making them less reliable.
Surge protection solutions
Organizations can't depend on the electrical distribution system, or electricity providers, to reduce or eliminate disruptions. The only proactive approach is to install appropriate surge protection on each power system, as well as wired data and communication devices.
Surge protection technology limits transient voltages by diverting or limiting surge currents. Surge protective devices (SPDs) are a cost-effective way to prevent downtime, improve system and data reliability, and eliminate equipment damage due to transient surges entering through power and communication lines. The use of SPDs is often specified by the end-user or mandated by code or local requirements.
Types of surge protection technology
The three most common solutions for voltage transients are Metal Oxide Varistors (MOV), Silicon Avalanche Diodes (SADs) and Gas Discharge Tubes (GDTs). MOVs are the most common SPD technology. They are found in everyday surge protection power strips. However, MOVs cannot handle sustained overvoltage.
SADs are best used for high-speed data transmission, low-voltage DC applications and networked devices. This SPD has a faster response time than MOVs and are built to experience avalanche breakdown, which is a type of electric current multiplication that causes a sudden and swift increase in current-diverting capacity.
GDTs are the most rugged SPDs available. They provide connection between the power line and the ground line. When a power surge occurs, the gas molecules break into positive and negative ions and become an extremely effective conductor. The surge current passes through to the ground line, diverting the surge away from protected devices. While GDTs are ideal against extremely large surge events, they are less effective reacting to fast traveling or sudden surges.
Using a layered strategy
The best surge protection strategy involves a layered approach, beginning with the building's main power source, as this is the primary entry point for power surges and spikes originating outside the facility. The second layer should shield network equipment against power surges originating from within the facility, such as due to use of heavy equipment, power tools, or HVAC systems cycling on and off.
A final third layer of SPDs should protect all other electrical pathways into a facility, especially cables that pass outdoors. Electricity doesn't care where a cable originates. It can travel in any direction as long the cable provides a pathway.
The key principal is to put SPDs at both ends of connections. This is especially crucial with exterior systems, such as surveillance cameras or telephone lines that connect to fire alarm panels and ATMs. When designing a surge protection plan for any facility, matching the application with the need is key to mitigating power surge issues. For example, every access control system needs surge protection to its supplied power connection, as well as to the facility power entry point.
The impact of a power surge or spike in a retail environment can be catastrophic to point of sale (POS) devices, refrigeration equipment, food and beverage machines, fire and security systems, and fuel pumps. Investing in surge protection for all network-centric systems is the smartest way to go. It is especially critical to protect all safety and security systems in such high-risk locations as public and private schools and hospitals.
Surge protective devices sacrifice themselves to protect an organization’s systems and devices. The lifespan of an SPD will depend on how often is called upon to provide protection, along with the severity of power surges experienced. It is important to conduct periodic maintenance to inspect SPDs.
Proactive surge protection is a must
While improvements in the electrical supply grid are in the offing, we must acknowledge that they are not likely to be fully implemented on a broad scale for quite a long time. The cost of a proactive surge protection plan is usually less than the sales tax on the system. When you think about how much it will cost to replace a full system, or even components of a certain system, it becomes clear just how cost-effective a proactive surge protection plan really is. Surge protection should be an integral part of the design process from the start through collaboration between end-users, consultants, systems integrators, and qualified electrical power solutions vendors.