Most of us have more devices than we have plugs in the wall, which is why you’ll likely find a surge protector behind most people’s televisions and under our desks.
However, not all surge protectors are alike, and some even put your gadgets at risk. We talked to an electrician to sort out how to tell the good ones from the bad ones and safely use them.
A lot of electronics require a lot of outlets. For example, with a basic desktop computer, you need an outlet for the monitor, CPU, speakers, wireless router, modem, printer, and any other gadgets you may wish to connect.
There’s the television, stereo receiver, preamp, subwoofer, speakers (sometimes), turntable, DVD or Blu-ray player, gaming consoles, and cable set-top box for a home theater system.
While the typical solution is to get either a good whole house surge protector or power strip, these options have significant differences to consider. Most surge protectors are also power strips, but power strips do not necessarily surge protectors.
You’ll often find them in the same aisle at the hardware or store. But you should know the difference before buying.
- How Surge Protectors Work
- Types of Surge Protectors
- What to Look for in a Surge Protector
- Performance Ratings to Consider
How Surge Protectors Work
Surge protectors help protect electronic equipment, including computers, televisions, home theaters, game systems, and appliances, from electrical surges and spikes — increases in average electrical line voltage. Surges carry less voltage than spikes but can last longer, up to a few seconds.
They’re often the result of a sudden change in demand for electricity, such as appliances or equipment that draw a lot of power — air conditioners, furnaces, refrigerators, or laser printers, for example — turning on or off. Spikes are much shorter in duration.
They last only fractions of seconds but can carry thousands of volts. Spikes can result from storms or problems on power lines, such as shorts caused by downed trees or limbs.
Both surges and spikes can damage electronic equipment beyond practical repair, either instantaneously or over time.
Even small surges or spikes can eventually destroy or affect the performance of electronic equipment. Surge protectors, also known as surge suppressors, absorb and channel damaging excess voltage away from devices connected to them.
However, they have a limited capacity to absorb. Once the capacity is reached, the unit can no longer protect your equipment and should be replaced.
Types of Surge Protectors
- Power-strip surge protectors have a cord that gives you the flexibility to position them close to your equipment. Some have mounting holes that allow you to hang them on a wall. They typically have 6 to 12 power outlets.
- Wall-mount surge protectors have no cord. They typically have between 2 and 6 outlets. Mobile models are compact and have a plug that folds into the device’s housing.
There’s a difference between a basic power strip or multiplug adapter and a surge protector. Power strips and adapters offer additional outlet space but provide no surge protection. You can identify surge protectors by the ratings for joules and voltage protection on the packaging.
What to Look for in a Surge Protector
Now that you understand what a surge protector is and how it works let’s dive into what to look for in a surge protector.
Surge Protector vs. Power Strip
Not all devices that provide additional outlets are surge protectors. Power strips allow you to plug multiple devices into a single wall outlet but won’t protect your devices from electrical spikes or surges.
Surge protectors often feature a light labeled “surge” or “protected,” distinguishing themselves from power strips and confirming that they’re still functional. If your surge protector features one of these lights, but it isn’t illuminated when plugged in, there’s a strong chance it needs to be replaced.
The bottom of a surge protector should also indicate any certifications the device has. Look for the Underwriters Laboratories logo (UL) or see if the device identifies itself as a “Transient Voltage Surge Suppressor” (TVSS) or “Surge Protective Device” (SPD).
Underwriters Laboratories is a not-for-profit that tests the safety of various electronics. Their symbol or the above titles (TVSS or SPD) indicate that a surge protector meets the UL 1449 minimum performance standards for a surge protector.
If you’re debating the merits of a surge protector vs. a power strip, the only benefit to a power strip is its slightly lower price. Spending just an extra few dollars to buy a surge protector could save you hundreds or thousands of dollars in the long run.
Battery Backups – UPS
Some surge protectors include a battery, preventing your devices from losing power immediately in the event of a surge or power outage. These devices are called Uninterruptible Power Supplies (UPS) and are primarily used for computers or other devices that store important data.
When power stops flowing from the outlet, the battery inside the UPS gives your computer time to safely shutdown. Software linking the two can give your computer the command to shut down when the UPS switches over to battery power, ensuring your data stays safe.
Number of Outlets
One of the most important considerations when buying a surge protector is the number of outlets it provides. If you’re connecting an entertainment system or a home office, you need to make sure you have a spot on the surge protector for all of your devices and ideally a few extras should you choose to add devices to your setup in the future.
And remember that the number of outlets doesn’t necessarily equal the number of devices you can plug in; many devices feature oversized power adapters that can block adjacent outlets. Some surge protectors are designed with large plugs in mind, offsetting their outlets from one another and placing outlets on multiple edges.
Whatever design you choose, make sure you have both the appropriate number of outlets for all of your devices and enough excess space to accommodate oversized power adapters.
While it’s understandable to think that power surges can only come over power lines, dangerous amounts of electricity can also flow through phone lines, cable lines, satellite lines, and even ethernet cables.
Many surge protectors have in and out ports for all of these cable types, ensuring that your devices are safe from surges, no matter the source.
Surge protectors often offer a warranty to repair or replace devices connected through the protector in the event of a surge. However, it can be difficult to definitively prove that a power surge that made its way through your surge protector is the source of damage.
And without definitive proof, manufacturers are understandably hesitant to cut a check. The process often involves shipping your surge protector back to the manufacturer at your cost and paying to have a professional diagnose your electronic(s).
Because of this, warranty often claims only make sense on big-ticket items.
Performance Ratings to Consider
Product packaging is designed to attract attention while conveying information. This can seem confusing, what with all the specs and features. Focus on these first:
Joules (higher is better)
The number of joules listed for the surge protector represents the energy absorption rating. Think of it like a shield that blocks excess energy. Higher numbers mean the surge protector can sustain more (or bigger) hits through single or multiple events before wearing out.
So if a surge protector has 500 joules of protection, it could theoretically handle ten 50-joule hits, or four 125-joule hits, or two 250-joule hits, or one 500-joule hit. Small electronics (like lamps, radios, and battery chargers) are fine with joule ratings under 1000.
But for computer or home theater equipment, you’ll want to consider surge protectors with joule ratings of 2500 or more.
Clamping Voltage (lower is better)
The clamping voltage—sometimes referred to as the Voltage Protection Rating (VPR) or Suppressed Voltage Rating (SVR)—indicates when the surge protector will activate to divert excess voltage to the ground.
While the protection offered by joules sounds good, it’s the clamping voltage (maximum voltage to be allowed through) that ends up being more effective.
Lower numbers mean the surge protector is less tolerant of excess voltage. So when comparing a surge protector with 330 V clamping voltage (best option) versus one with 500 V clamping voltage, the latter will allow a higher surge or spike to occur (which can damage components) before doing anything about it.
Response Time (lower is better)
The response time (typically measured in nanoseconds) indicates how quickly a surge protector will react in order to divert excess voltage. While electronics seem to work instantly, they require time to operate.
Response time goes hand-in-hand with the clamping voltage. Surge protectors with lower response times activate faster in order to redirect excess voltage before it has a chance to cause damage. If you want the best, choose ones with response times of one nanosecond (or less).
UL 1449 (must have)
The Underwriters Laboratories UL 1449 is the recognized safety standard that applies to every Surge Protective Device (SPD).
This standard lists the certification criteria, design requirements, and product performance testing that manufacturers need to meet for a surge protector to be considered safe for consumer use.
If a surge protector doesn’t have this displayed somewhere on the box, it may not be the right choice for protecting your equipment.
Make sure you’re informed before you buy and read the box’s back or the product details before purchasing anything. You don’t want to invest in a surge protector only to find out that it’s far too weak to protect your devices, or it’s a surge protector in name only.