If I were recommending a surge protector for general home office or audio/video use, I’d suggest the APC Surgearrest 3020J. It offers best-in-class surge protection and enough outlets for almost any application. But depending on what you’re going to do with your surge protector—and even on where you live—another model may work better for you.
We also liked the Belkin BG108000-04 Conserve, a close second in our surge protection tests. The Belkin comes with a wireless switch that lets you turn off 6 of its 8 outlets from up to 60 feet away. And if you want something more portable for travel, we discovered that our pick for best mini USB power strip (or alternatively, the Tripp-Lite SK120USB, which appears to be the same thing, but was in stock at the time of testing) also provides a respectable amount of surge protection for its size.
Finally, if all you want is a couple of extra outlets and you don’t care to pay extra for outlet-access-maximizing design, we found that your typical $10 surge strip isn’t all that much worse than many of the fancier, more expensive models we tested when it came to clamping down on power surges.
Why should you trust me?
I’ve conducted extensive technical testing of amplifiers and other audio electronics as Stereos Expert for About.com and as an editor and writer for Sound & Vision and Home Theater magazines. I’ve also been involved in various side projects dealing with high voltage, including building amplifier power supplies and high-voltage supplies for chemical engineering work. So among those who write regularly about consumer electronics, I’m one of the most experienced in dealing with high voltage.
How much protection do you need?
What we can tell you is that more protection is most likely better than less protection and that our tests showed significant differences in performance between models.
There isn’t a single good answer to this question. What we can tell you is that more protection is most likely better than less protection and that our tests showed significant differences in performance between models.
You can expect a cheap surge protector to clamp a 600-volt surge down to about 300 volts. Most mid-range $20-$40 models will clamp the same surge down to about 280 volts, and the best performers can clamp down to under 200 volts. (We explain all the ins and outs of how and why these things work later on in the How surge protectors work section.)
However, there’s a bit of a tradeoff between surge protection and longevity. If surge protectors were video game characters, the joule rating would represent their health points—they can only take so many hits until they run out and die. Typically, the higher the joule rating, the longer a protector will protect for (cheaper protectors tend to have lower joule ratings). But, other things equal, a protector that clamps a 600 volt surge down to 180 volts as opposed to 280 volts may wear out faster because it absorbs 420 volts as opposed to just 320 volts.
Whether or not any given product will survive a surge, protected or not, varies greatly from brand to brand and even product to product.
Whether or not any given product will survive a surge, protected or not, varies greatly from brand to brand and even product to product. There’s no way to know for sure, unfortunately. The truth is, you might not even need a surge protector. For most people, it’s just a cheap and convenient form of insurance and an easy way to increase the number of outlets at your disposal.
Besides, in most situations, significant surge events are rare. I’ve encountered surge damage only twice in my five decades: at my parents’ old house on the Mississippi Gulf Coast, where lightning storms were frequent, and at the old Spin magazine offices on 18th St in NYC thanks to a misbehaving elevator.
How we picked
There’s not much good information about surge protectors in professional reviews, consumer reviews on Amazon.com, or other sources. Unlike a typical tech product, a surge protector’s performance can only be easily observed when it fails. Your surge protector could stop a hundred individual 500-volt surges and you’d never know until the day it stopped working.
Thus, reviews tend to rank surge protectors by their joule rating, a measure of energy we’ll discuss later, or by the size of the warranty against damage to connected devices due to failure of the surge protector. It’s important to note that these warranties are determined at least as much by marketing and accounting concerns as they are by engineering data.
Since we couldn’t find a professional reviewer who had put significant work, resources, and technical knowledge into a surge protector evaluation, we knew we’d have to do it ourselves. So I set to work studying up on the subject by reading technical materials on the web and data sheets for key components used in surge protectors. I then gathered samples of surge protectors, concentrating primarily on ones that offered at least eight outlets. I also selected some models with unusual features so I could try them out and see how useful they might be. I played around with them at home to gauge how well their designs and features worked. In total I picked up 15 products that ranged from $10 to $250. Afterward, I gave them to electrical engineering consultant Dan Siefert to test their electrical performance.
Before we get into our recommendations, one more note. There are all sorts of features you can find on surge protectors, and you know better than we do if you need them. Generally, it’s a good idea to get a surge protector with at least two more outlets than you need. A few of the AC outlets should have room to accommodate wall warts. You may want USB-charging outputs. You may want a long cord or a short one. And you may want some sort of auto turn-off feature to reduce power consumption. Many of the models we tested are available in similar versions with more or fewer outlets, with or without USB, and so on.
The best overall choice: home theater and office
Why did we pick the APC Surgearrest 3020J? Because it delivered the best surge protection and a decent mix of features for not too much cash. The Surgearrest 3020J clamped a 600-volt spike down to 160 volts, while most of the other models we tested only managed to get the spike down to between 250 and 400 volts.
This means that the Surgearrest 3020J absorbs more of the energy from a spike, making the spike less likely to damage a component connected to the surge protector. The Surgearrest 3020J’s noise filtration reduced radio-frequency noise at the AC outlets by an average of -30.4 dB, which is above-average performance among the units we tested.
It’s worth noting that because the Surgearrest will absorb surge/spike energy more eagerly…its metal-oxide varistors may degrade faster.
It’s worth noting that because the Surgearrest will absorb surge/spike energy more eagerly than most of the surge protectors we tested, its metal-oxide varistors, or MOVs (the parts responsible for the the actual surge protection), may degrade faster. But at the same time, its joule rating was the highest of all the standard surge protectors we tested—almost 10 times the 312 joules of the inexpensive Belkin surge protector we tested and about three times that of many other protectors in this price range. This bodes well for its long-term reliability. As with any surge protector, it wouldn’t hurt to replace it every few years just to be safe—maybe more often if you live in an area where lightning strikes and power failures are common. Because there’s no way to tell how much the MOVs have aged, you’re better safe than sorry when it comes to ensuring peace of mind.1
With six wall-wart-friendly outlets and five standard outlets, plus surge protection for one phone line and one antenna/cable connection, the Surgearrest 3020J has the features most commonly needed in home theaters and offices that have a lot of gear. It has an 8-foot cord and a $300,000 connected-equipment warranty. The antenna/cable line clamped incoming power to 14 volts, but as with the other units we tested, the phone line didn’t measurably clamp the voltage spikes.
Dan Siefert and I were able to disassemble the Surgearrest 3020J and found the guts impressive: two fused MOVs each for hot to neutral, neutral to ground, and hot to ground. “That’s important, because you don’t know which conductors the surge is going to come in on,” Dan pointed out. The AC lines also had two supplementary MOVs, and there was also an array of diodes, fuses and MOVs for the coax and phone connections.
At a typical cost of around $25, the Surgearrest 3020J is a terrific bargain, because it costs less than many competitors, yet it performs better and offers enough outlets for almost any home office or home theater.
A runner up with a wireless kill switch
The Belkin BG108000-04 Conserve was almost as good at suppressing surges as the Surgearrest 3020J was, clamping the 600-volt spike at 180 volts, but its real selling point is that it comes with a big wireless kill switch that lets you turn it on and off from up to 60 feet away. You can stick the switch right next to your home office light switch, so you can easily power-down your computer and peripherals when you turn off the lights. Also, all eight outlets are spaced widely enough to accommodate wall warts.
Noise filtration was acceptable but nothing special at a -24.5 dB average. It has a short 4-foot cord, a $100,000 connected-equipment warranty, and a rating of 1,000 joules, which isn’t particularly high. That, combined with the fact that it clamps surges down further than most protectors, means it may also wear out faster, so keep that in mind if you live in a surge-prone area. The BG108000-04 doesn’t have protection for coax, Ethernet, or phone lines, but that’s probably not a big deal for most people.
It’s worth noting that there are multiple user reviews that complain about the quality of the switch, but feedback is by and large positive with 107 out of the 149 total reviews being either 4- or 5-star reviews. Personally, I’ve found the switch a little persnickety, but a good solid push in the center of the toggle usually gets the desired result.
The best portable
We tested only three portable units—there aren’t that many on the market—and the one we’d buy is the Tripp-Lite SK120USB, which is the same unit as the Accell Home or Away that we chose as the Best Travel Power Strip (with USB). Its surge protection was nothing special; it clamped the 600-volt spike at 350 volts. This is worse than most, but excusable given the convenience afforded by its size and good design. The Belkin BST300bg had somewhat better results at 280 volts, but the Belkin is so bulky that we prefer to settle for a little less performance in favor of usability, picking the Tripp-Lite.
Both the Tripp-Lite and the Accell share a compact design that’s slim enough to fit in most laptop bags. It has three outlets and two USB charging outlets. Inside, there’s just a single fused MOV, but at least it gives you more protection than a plain power strip. It has no filtration circuits but absorbed an average of -8.0 dB of noise anyway.
What about cheap power strips?
It didn’t perform especially well, clamping the 600-volt spike to 300 volts…
We wanted to see how a cheap power strip would compare to the big surge protectors, so I picked up aBelkin F5C047 for about $10 at Home Depot to represent the low-priced end of the spectrum. It didn’t perform especially well, clamping the 600-volt spike to 300 volts, but Dan was surprised to find that it delivered -16.2 dB average noise filtration even though it didn’t have filtration circuitry.
However, we did find that it has fused MOVs strapped across all three AC conductors, which is better than we expected; both of us have seen power strips with just one MOV and no fuse.
If you just need a power strip, this one’s probably fine, and it shows that in day-to-day use an inexpensive power strip isn’t necessarily any worse than a more expensive surge protector. The question is, how long will the inexpensive strip last? The F5C047 is rated at 312 joules, so it won’t take a lot of punishment. People who live in spike-prone areas with lots of lightning storms and frequent power failures should consider something with a much higher joule rating.
What about high-end home theater line conditioners?
Long story short, they’re probably not worth your money. Despite being solidly manufactured out of heavy-duty components, our testing showed that these things can actually produce worse surge protection than even a cheap $10 strip.
Long story short, they’re probably not worth your money.
Just to see how a higher-end, so-called “line conditioner” product would perform, we tested the $250 Monster HDP 1800, which is about the size of a typical Blu-ray player and designed to fit into an equipment rack. The back panel has eight outlets. The HDP 1800 not only has a 5,526 joule rating, it includes T2 circuitry, which Monster says disconnects the unit from the power line in the event of a surge, sounds an alarm to tell you you’ve got a problem, and restores power only when conditions are safe. It also has separate sets of filters intended to optimize performance for analog audio devices, digital devices, and devices using power-line communications (PLC) technology.
The HDP 1800 didn’t do all that well on the surge test, clamping the 600-volt spike down to 400 volts. While the high clamping voltage might allow the MOVs to last longer, it’s possible that connected equipment will be less protected than with some of the better conventional surge protectors we tested.
Filtration results were so-so: -30.3 dB for the “digital component” outlets and -17.4 dB for the “analog audio” outlets. But when we disassembled the device we found much larger, industrial-grade MOVs than in the other units. “This thing looks like it can take a whallop,” Dan said. Overall, we were left uncertain what to say about the HDP 1800. Clearly it’s built far better than the other units, and it would almost certainly last through a lot more spikes and surges, but its electrical performance seems to fall behind that of the best surge protectors in this test.
How we tested
Dan Siefert, introduced earlier, is an engineering consultant who has worked for Harman International and several other electronics companies. He is the principal of One on One Technical Products, a consulting firm in Thousand Oaks, California, and we called him in to help test our chosen units.
Because there are so many surge protectors out there, we decided to collect 16 samples from broadly-distributed brands so we could get a representative sample of what’s out there.
Dan started his tests by using a Berkeley Model 3020 line noise generator to inject a 50-microsecond spike into each surge protector, then measuring the voltage at the surge protector’s outlets. He did this in 100-volt increments, starting at 100 volts and going up to 600 volts, to see how effectively the surge protectors “clamped down” on the spikes. He did the same tests for devices that offer protection for Ethernet, phone, and/or antenna/cable connections.
He then injected radio-frequency noise in two bands—1 to 50 megahertz, and 20 to 200 MHz—into each surge protector, and used a radio-frequency spectrum analyzer to measure how much noise was getting through to each surge protector’s outlets.
What else did we test?
The Accell D080B-009K Power Squid has a unique design with five short cords emerging from the body of the surge protector. The idea is that any of the cords will take a plug or a wall wart. Performance was OK, reducing the 600-volt spike to 280 volts and reducing noise by an average of -33.0 dB. I don’t care for the design because it cluttered the area under my desk. But it might come in handy for certain situations, such as if you have to connect several power tools.
The Belkin BST300bg offered the best surge protection of the three portables we tested, clamping the 600-volt spike to 280 volts and reducing noise by a whopping -35.6 dB. It has two USB outlets for charging. It also has fused MOVs strapped across all three AC conductors. However, the bulky design makes it harder to pack into a laptop case than the TrippLite SK120USB.
The Belkin BSV602bgDP is one of those units that expands a two-outlet wall socket into six outlets, and it also has two USB charging outputs. Performance is average, clamping the 600-volt spike to 280 volts and reducing noise by an average of -24.2 dB. It’s an OK product for those who want something like this, but I didn’t like the way it sticks out from the wall or the way it wobbled when I connected and disconnected AC plugs.
The Dynex DX-SF127 is a rather generic unit sold by Best Buy. Performance is about average: The 600-volt spike was clamped to 280 volts, and average noise reduction was -26.9 dB. Nothing to write home about, at the very least. At $20 for 12 outlets (four spaced for wall warts), two USB charging outlets, and a 1,200 joule rating, the DX-SF127 is a good buy.
The Fellowes Mighty 8 has an eccentric polygonal design that allows five of its eight outlets to accept wall warts. Performance was OK, clamping the 600-volt spike to 290 volts and reducing noise by an average of -29.2 dB. I didn’t like having the cords emerging from the Mighty 8 in all directions, but I suppose some people might like it, and at an average price of about $20 it’s a reasonably good buy.
The Monster AV 775G has Monster’s Greenpower feature; plug a component with high current draw, like a TV or an A/V receiver, into the control outlet, and whenever you turn that device on, three other outlets will switch on automatically. But only one of the seven outlets is spaced to accommodate a wall wart, and performance was average: the 600-volt spike was reduced to 280 volts, and average filtration is -21.4 dB.
The Monster MP EXP 600 AV is basically a glorified power strip, with antenna/satellite protection added and a pretty impressive 1,080 joule rating. Surge protection is average, clamping the 600-volt spike to 280 volts, and noise filtering is excellent at -31.5 dB. However, it costs about $30. Unless for some reason you just really love the power strip form factor, you can get a larger, more capable unit for less.
The Monster Outlets to Go MP OTG300 is a portable unit with three outlets and two USB charging outlets. It’s similar in size to the TrippLite SK120USB, and appears to have come from the same original manufacturer. However, it doesn’t have surge protection.
The SmartStrip LCG 3E, like the Monster AV 775G, has one outlet with a current sensor, so when you turn on whatever’s connected to that outlet, six of the unit’s other outlets turn on. The difference is that the sensor outlet’s sensitivity is adjustable so it can work with almost any connected device, not just with high-current-draw devices as with the AV 775B. Four of the LCG 3E’s 10 outlets are spaced to accommodate wall warts. Clamping performance was about average, reducing the 600-volt spike to 275 volts, and noise filtering was excellent at -32.9 dB. At about $30, the LCG 3E is a pretty good buy if the auto turn-on/off feature appeals to you.
The TrippLite HT1210SAT3 has a super-long 10-foot cord, an impressive 2,880-joule rating and a $250,000 connected gear warranty. With 12 outlets (four spaced for wall warts) and protection for cable, satellite, and DSS (digital satellite) as well as phone/Ethernet, its feature package is impressive. While it couldn’t match the clamping performance of the APC Surgearrest 3020J or the Belkin BG108000-04, it was still a little above average, reducing the 600-volt spike to 250 volts. At -26.3 dB average, its filtration performance was respectable. But it sells for about $45, and we can’t think of a reason why we’d buy this instead of the Surgearrest 3020J.
How surge protectors work
To understand the tests we did, you need to know a little about how surge protectors work. Fortunately, they’re simple.
Surge protectors rely mainly on devices called metal-oxide varistors, or MOVs. A MOV works sort of like a runaway truck ramp on a mountain pass. Just as the ramp routes the truck off the highway so it can’t do any harm, then slows the truck to a stop, an MOV routes surges and spikes off the main electrical line then dissipates their energy so it can’t harm whatever’s plugged into the surge protector.
A MOV is connected across two conductors of an AC line. Below a certain voltage, the MOV doesn’t conduct electricity. Above a certain voltage, it conducts, effectively “shorting out” the surge so it can’t damage the components connected to the surge protector. A voltage surge that exceeds the capacity of the MOV will cause it to short completely. Like a paper clip plugged across a wall outlet, the shorted MOV instantly blows open (think July 4th). To minimize the fireworks potential, there’s usually a fuse in series (in line) with the MOV. It is designed to blow before the fireworks begin. Unfortunately, when the fuse goes, the MOV is also removed from the circuit and you have no surge protection at all.
MOVs are rated in joules. The joule is a measure of quantity, not level. Where a volt is like the force behind a boxer’s punch, a joule is like the damage done to his opponent by the punch. It’s the total amount of delivered energy, whereas a volt is a momentary measure of energy intensity. Just like punches, the effects of joules add up. The rating of an MOV—or a surge protector with a joule rating—indicates the total energy it can absorb from electrical spikes and surges before failure. So 100 1-joule spikes will wear out an MOV the same as a single 100-joule spike.
…the higher the joule rating on the MOVs, the longer the surge protector will continue to function.
If this is giving you the idea that surge protectors don’t last forever, you’re catching on. The more MOVs employed, and the higher the joule rating on the MOVs, the longer the surge protector will continue to function. One MOV manufacturer Dan questioned on this topic said that MOVs can typically last 25 years in a home setting. But of course, given a bad-enough spike, they could fry tomorrow.
Many surge protectors also include electrical filters that reduce the amount of electrical noise coming in on an AC line. We’ll see later why that may or may not be necessary.
What causes surges?
The primary source of surges and spikes in most homes is appliances. When a large, motor-driven appliance shuts off (either manually, automatically, or due to AC power failure), energy stored in the motor coils can flow back down the power line, a phenomenon called inductive kick. It typically shows up as a spike of about 500 volts that lasts somewhere between a few microseconds and a couple of milliseconds. Inductive kick can come from appliances such as refrigerators and air conditioners, or from industrial devices such as elevators and machine tools.
The primary source of surges and spikes in most homes is appliances.
The other most common source of spikes and surges is lightning, but most lightning surges aren’t caused by direct strikes. They’re caused by lightning passing near your local power lines. The magnetic field produced by the lightning generates high-voltage electricity in the lines, which can flow into your home. If your home or power line suffers a direct lightning strike, it’s unlikely any consumer surge protector can absorb the millions of volts involved.
The obvious conclusion here is that some people need surge protection more than others. If you live where lightning storms are common, good surge protection is a must. If you live where lightning storms rarely occur, it’s not as big a concern. Likewise if you have a lot of large appliances, or you work in an office that’s part of an industrial facility, surge protection is more important.
Also, note that many electronic devices have their own MOVs built in, and many aren’t all that vulnerable to minor surges in the first place.
How important is noise filtering? Again, it depends. All power supplies, whether internal or external, have noise filtration built in—in most cases, enough to prevent any noise coming in on the AC line from interfering with the operation or performance of your electronics. Still, it’s possible that a badly designed power supply could throw enough noise back into your lines to cause problems. Noise filtration probably isn’t something you need to worry about unless you’re having some sort of noise problem in your audio or video gear (which can, of course, include computer peripherals).
Wrapping it up
The field of surge protection is pretty mysterious. Few people have an accurate idea how much of a surge/spike problem they have. Since we’ve never seen a surge protector with a joule meter that shows how many hits it has taken (a great idea there for the taking, manufacturers!), we have no idea how much work our surge protectors are doing on a regular basis or what condition they’re in. Furthermore, we have little way of knowing how vulnerable our connected components are to surges.
All that said, we think the APC Surgearrest is good, cheap insurance for all your audio/video and office electronics. The Belkin BG108000-04 Conserve is a very close second, with a great wireless switch feature for conserving power. The TrippLite SK120USB (or, probably, the apparently identical Accell Home or Away) offers some degree of convenient surge protection for travelers. All three are excellent values—and if they save just one component they’ll pay for themselves many times over.