What is a Surge Protector?

Before we get into the whole house surge protection discussion, let’s first take a look at a basic surge protector.

What is a surge protector? What are its parts? Are there any types?

All of the answers to these questions will be tackled in this article so we hope that you stick around to learn more.

Basically, a surge protector, sometimes called a surge suppressor, is a device that’s been designed to protect your electronics from unwanted voltage spikes.

How does it do this? A surge protector will try to limit the voltage that goes through an electronic device by two ways. Blocking the voltage is the first way and the second is by shorting to ground the voltage spikes that is above a safe level.

You will encounter some vocabulary like surge protection device (SPD) or transient voltage surge suppressor (TVSS) when dealing with this subject. Those two terminologies are basically a description of the devices that are installed in a lot of electrical systems for the purpose of voltage spike protection.

If you have a power strip at home then you might probably have some basic surge protection. If you bought a power strip that has some surge protection capabilities you will quickly see this in the label. But there are power strips in the market that are mistakenly marketed as having surge protection.

Let’s briefly talk about the specifications. First is the clamping voltage which is sometimes referred to as the let-through voltage. This will indicate what amount of voltage surge will cause the protective parts inside a SPD to redirect unnecessary power from the protected line.

Generally you get a better protection if you see a lower clamping voltage but sometimes the overall protection is not that long. The lowest voltage protection levels are 330V, 400V and 500V and they’ve been described in the UL ratings. A typical clamping voltage for a standard 120V AC device is at 330V.

Next specification is the Joules rating and this is basically a number which tells you how much power a metal oxide varistor (MOV) surge protector can absorb in a single event without any failure.

In this case, it’s a complete opposite compared to the clamping voltage. If you see a lower number then you can expect a longer life expectancy provided that it can reroute more energy elsewhere, thus allowing it to take in less spikes.

Surge protectors don’t really work right away; there’s a little delay. If there’s a longer response time, the connected devices will be more exposed to the surge. But the thing is that surges don’t happen at an instant too as they take a few microseconds to reach their highest voltage. A surge protector with a very fast response time would quickly catch the spike and lessen its highest intensity.

Whew! That was quite a lot and if your head is already hurting then you’re not alone. Obviously this site is all about surge protectors but more specifically the types that you use in your house.

We still have a lot of things to discuss and in the future we’re going to list down the most popular whole house surge protectors.

Do you have any experience with surge protectors? If you have any type of feedback, it would be great if you could leave a comment below. Thanks!

2 thoughts on “What is a Surge Protector?

  1. MOV based surge protection is not the best method of preventing surge damage. Whole building surge protection lets through too much voltage to be effective. They will tell you that you need point of use protection to provide “layered protection”. This is because they only have MOVs in both solutions. MOVs can not see the current rise. The dI/dt is what actually kills your electronics.

    The best solution is a series mode filter that actually suppresses the surges. This low pass filter lets the good 60 Hz energy through and filtering out the higher energy that is the surge. MOVs wear out no matter how high the Joule rating is. In fact Joule rating is not a performance specification. Only Voltage Protection Rating and Maximum Continuous Operating Voltage.

    80% of surges originate from inside of a building so having protection at the service entrance does little good anyway.

    • Thank you for sharing your thoughts Jim as I’ve learned something informative. You’re right, many of the people who are satisfied with whole house surge protectors are still suggesting point of use protection like power strips to protect their sensitive electronics. It’s also true that MOVs do wear out after some time and it’s good to know that there is actually a better solution. I will have to look for more information about non-MOV surge protectors.

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