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Surge Protector Buying Guide

Protect computers and electronics from damaging power surges.

This buying guide will help you:

  • Understand what a surge protector is and recognize key features
  • Learn the best questions to determine the right surge protector for your equipment
  • Answer frequently asked questions about surge protectors

Surge protectors guard electrically powered equipment against power surges and spikes, which are temporary and potentially damaging voltage increases along electric wires and cables. These small devices are plugged into wall outlets, either directly or via cable, and offer one or more protected outlets for safely powering connected devices.

surge protector Eaton

What equipment needs surge protection?

Any device that plugs into an AC outlet can benefit from a surge protector. The most vulnerable pieces of equipment are those with memory and sensitive electronic circuitry. A surge protector is essential for:

  • PCs and computer peripherals such as printers, monitors, and routers
  • TVs, DVRs, cable boxes, satellite receivers, sound systems, and other home theater components
  • Video game systems
  • Lighting, tools, small appliances, and office equipment

Note: If you need to protect a computer, consider an uninterruptible power supply (UPS), which provides surge protection and battery backup to allow a safe power-down in the event of an outage.

what to look for in a surge protector

Joule Protection Rating

power surge protector

Protection Alerts

Some surge protectors use LED lights and/or audible alarms to indicate they are no longer providing an adequate level of power protection to connected equipment. These indicators should be monitored regularly, so the surge can be replaced immediately if necessary.


Wondering what to look for in a surge protector? These three questions will help you determine what kind of surge protector you need.

1. What Am I Protecting?

The value of the equipment you want to protect is the most important consideration when choosing a surge protector. Devices that are critical to work/home life and those that are otherwise costly or fragile require a greater degree of protection. A higher joule rating is the best indicator of greater protection.

  • Choose a surge protector with a joule rating at the very least in the 200 to 400 range. Sensitive or costly equipment, such as computers, displays and audio/video equipment, warrants a joule rating of at least 1000. A joule rating over 2000 indicates maximum protection.
how to choose surge protector - joules

2. How Many Outlets Do I Need?

  • Count the devices you want to plug into your surge protector and purchase a model with at least as many outlets.
  • If any of your devices have right-angle plugs or transformers, be sure to select a model with adequate spacing between outlets to accommodate them.
  • Consider whether you will charge USB devices from your surge protector and identify models with USB-A charging ports so you can avoid using adapters.
how to choose surge protector - outlets

3. Where Will I Install My Surge Protector?

  • If protection becomes compromised, will you be able to easily see LED lights and/or hear your surge protector alarm? If you want to protect devices that run while you are not in immediate vicinity, be sure to select a model with auto-shutoff functionality.
  • If you need to mount your surge protector on a wall or along the side of a desk, be sure it has mounting tabs or screw holes.
  • If furniture or other objects will be between your surge protector and its AC outlet, gauge the distance between them and purchase a device with an input cord of adequate length. Models with right-angle plugs may be able to better negotiate tight connection spaces.
  • If your surge protector will be installed in an area with high foot traffic or might otherwise be vulnerable to the occasional impact, consider a model with metal housing.
how to choose surge protector - wall mount

3 Line Protection

Look for surge protectors that protect hot, neutral and ground lines (3 line protection) for the most thorough protection.

Data Line Protection

Computers and network equipment can be susceptible to power surges travelling over Ethernet (or coaxial/telephone/modem) cables. If you are using a wired Ethernet connection for your computer, look for a surge protector with one or more protected Ethernet jacks.

PoE Surge Protection

Hospital-Grade Protection

Hospital-grade surge protectors have safety enhanced outlets and plugs. They may also include special features that protect against electric shock and anti-microbial coating to inhibit the growth of bacteria on the device.

Individual Outlet Control

Some surge protectors offer the ability to switch off power to individual devices without interrupting power to all connected devices, which can improve efficiency and convenience in device management.


If you are travelling with equipment that needs protection, look for surge protectors with fold-down plugs and compact designs that can easily be stored in luggage, purses, briefcases and backpacks.

Specialized Use

Some in-line PoE surge protectors are IP66 rated for resistance to dust and water. These are ideal for outdoor applications like security cameras or digital signage.

Warranty and Insurance

A surge protector's job is to absorb the brunt of power surges and spikes so your equipment doesn't have to. This will take a toll over time, so look for models that come with lifetime replacement warrantees as well as insurance to repair or replace any connected equipment damaged by surges.

which surge protector should i buy
what is a good surge protector - isobar

Isobar Premium Surge Protection

Eaton's Isobar® line is the gold standard in surge protection with over 20 million units sold worldwide. It keeps essential IT-grade equipment protected with up to 5100 joules and offers robust EMI/RFI protection. Models offer data line protection, USB charging, metal casing, auto shut-off and other key features*. With up to 12 outlets in a variety of form factors and cord lengths up to 25 ft., there are Isobar options to fit a wide range of environments.

* Features vary by model.

Surge Protector or Power Strip?

Do not confuse surge protectors with power strips. Both products provide outlets for powering multiple devices from a single wall outlet, and power strips often look similar to surge protectors. But only surge protectors will guard connected devices against power surges and line noise. Look for words on the product or packaging like "surge", "protection" or "suppression," and also look for a joule rating.

What is the Difference Between a Power Surge and a Power Spike?

Can Other Power Products Provide Surge Protection?

Yes. Products like an uninterrupted power supply (UPS) and a power distribution unit (PDU) will typically include a degree of surge protection. A UPS will also provide battery power backup to connected devices in the case of an AC power outage. Look for some of the same criteria, like a joule rating, to evaluate the protection they provide.

ups surge protector

Are Eco-Friendly Surge Protectors Available?

Make sure your surge protector is RoHS (Restriction of Hazardous Substances) compliant. Features like individual outlet control and other special circuitry will reduce energy consumption and lower utility bills.

what is a good surge protector - rohs

How Long Do Surge Protectors Last?

what makes a good surge protector - isobar Components inside an Eaton Isobar premium surge protector prevent power problems from damaging your equipment.

Automatic Shutoff - Feature found on select surge protectors which automatically prevents power from reaching connected devices once the suppression circuit on a surge protector has been compromised.

EMI/RFI - Electromagnetic Interference (EMI)/ Radio Frequency Interference (RFI) are distortions or "line noise" on AC, telephone/modem, network or coaxial lines. They usually show up as audio static or video "snow" and are caused by other equipment operating on the same electrical system as the affected device.

MOVs - Metal oxide varistors are triggered when excess current passes through a surge protector. They are the components in the device that actually absorb the surge from the power source and divert it to the ground wire.

PoE - Power over Ethernet, as the name implies, is a technology for delivering power and network connectivity over a single Ethernet cable. This makes it ideal for powering and connecting IP devices like security cameras, access control readers, wireless access points (WAPs), VoIP telephones, POS systems, sensors and lighting.

Power Surge - A power surge is a temporary, unwanted and potentially dangerous increase in an electrical system. It is most often caused by a power grid interruption, followed by a resumption in which the line voltage is higher than normal.

Power Spike - Very short (1 or 2 nanoseconds) and potentially extreme voltage increase in an electric system, often caused by an electrical storm.

Why Buy from Eaton?

We know you have many brands to choose from. On the surface, they may all seem alike. It's what you don't see that makes the difference. With Eaton, you get solid engineering, proven reliability and exceptional customer service. All our products undergo rigorous quality control before they are offered for sale, and independent testing agencies verify our products meet or exceed the latest safety and performance standards. Our commitment to quality allows us to back our products with industry-leading warranties and responsive customer service. It's the Eaton difference.

Need help with your purchase?
We're always available to help with questions, including product selection, sizing, installation and product customization. Call us at +1 773-869-1776 or email