Surge 101 & the PowerSquid Difference:
Surges, Joules and MOVs – What the heck are they and why does it matter?
You know you’ve been thinking it: what exactly is the point of surge protection, and why is it so important? We know you’ve been pondering this because many of you have called and emailed us asking. So, to start, let’s address what a power surge is and how/why it damages your equipment.
A power surge, or spike, is a temporary increase in voltage in an electrical line that can originate from outside
or inside a home or office. While they are most notably caused by lightning strikes, they are often the result of brownouts. A brownout is the partial reduction in electrical power due to storms, mechanical failure, shortage, or even overuse by consumers. This can be outwardly noticeable in the periodic dimming or flickering of lights. As a brownout event returns to full power, there can be a brief surge of electricity that occurs on the back-end. Surges can also be the result of power transitions in appliances, the swinging of power lines in the wind or even simply flipping a light switch.
While a single, large power surge can cause damage to your equipment (think: lightning strike), the real problem is the cumulative effect of small surges over time. When surges repeatedly reach your sensitive electronic equipment (TV, computer, stereo, home theater system, etc...), they will eventually cause an effect called “electronic rust” to occur. This is the gradual decay of electronic components due to repeated exposure to small transient surges. The damage may not occur immediately or be outwardly evident, but over time your equipment will fail as the sensitive components are degraded. Ultimately, you end up with a very expensive heap of useless junk! Rats!
"So what can one do?" you ask.
Most equipment damage from surges and spikes can be prevented by the use of surge protectors. So, the simplest way to protect your equipment is to insert a surge protector between the wall outlet and your equipment. There are a variety of features that should be considered when evaluating your surge protection needs, but one critical feature to consider is how much protection are you going to get from any given surge protector.
Joules and MOVs: The most common way of rating the amount of protection that a surge protector will provide is to look at its joule rating. Although it may be easy to compare a surge protector's relative ability to protect (100 joule rating vs. 1000 joule rating), understanding what a joule is and what its associated joule rating actually means may come in useful.
According to the American Heritage Dictionary, a joule is, "A unit of electrical energy equal to the work done when a current of one ampere is passed through a resistance of one ohm for one second." Hmm, kind of technical...
So what does this mean with regard to surge protection? Well, a typical surge protector (PowerSquid included) uses Metal Oxide Varistors (MOVs) to redirect electric currents above a specified voltage (clamping voltage) instead of allowing the surge to enter the connected equipment. The MOV absorbs the excess electrical energy - here is where the joule comes in - and dissipates it as heat energy. MOVs are rated by the number of joules that they can absorb, which is a finite number. Ultimately, after the MOVs absorb all of the joules that they can, the surge protector will activate its Tripwire Circuit and sacrifice itself for the betterment of the connected equipment. In other words: you will have to replace your surge protector, which is almost always better than having to replace your 70" LCD Wide-Screen HD TV!
For more information on the subject, Google any of the key words in this section, or check out Wickipedia.org:
Voltage Spike