Surge Protectors: Everything You Need to Know and How They Work

Surge Protectors: Everything You Need to Know and How They Work

First things first, what exactly are surge protectors, and how do they work? One such safety system protects electrical devices like computers, washing machines, televisions, etc. from sudden and abnormal voltage spikes. The surges and fluctuations in voltage are caused by lightning strikes, faulty wiring, power outages, and other electrical system faults.Therefore a surge protector is installed to safeguard sensitive electrical equipment from power surges.

What is a Surge Protector?

All electrical equipment with electronic circuits is prone to damage by abnormal outbursts of high voltage. This is where a surge suppressor comes into the scene, working as an electrical installation protection device. It is designed to safeguard electrical appliances and equipment by restricting high voltages and diverting surge currents.

Transient voltage can cause significant damage to electrical devices with complicated circuits. Here, the role played by a surge protection device (SPD) is highly commendable, as it limits the flow of voltage. Here in Texas, you can take the help of expert electricians in Greenville or in your hometown, that can ensure all your devices are protected, by installing such safety equipment.

There are electrical protection devices that are installed in the main electrical panel box. This is the core of any electrical system at a residence or workplace. It is designed to prevent over voltages in the panel before it enters your home. Unlike point-of-use SPDs that prevent a spike after it has entered your house, these panel-installed ones divert the excess voltage into the grounding system. It can also prevent minor fluctuations in energy that occur some several hundred and thousand times a day.

What Causes Sudden Spikes in Voltages?

Some common reasons for power surges and voltage spikes are downed electrical lines, electrical grid failure, thunderstorms & lightning, tripped circuit breakers, and faulty wiring. Very high spikes in voltage are caused mainly due to severe lightning strikes and interruptions as a result of storm damage. This can happen during a specific time of the year.

Overvoltage generates excess heat, inflicting serious damage to motherboards of computers, electronic circuits, power fuses, thermostats, and various other sensitive electrical components. If the power surge is all of a sudden and large enough, it can significantly damage electrical devices that are connected downstream.

How Do Surge Protectors Work?

In normal circumstances, when there is no voltage fluctuation or abnormalities in current flow, the SPD does not influence any electrical system. But when there’s a voltage spike, the surge suppressor diverts the impulse current instantly. It acts as an open circuit but behaves like a closed circuit, limiting the voltage to an acceptable value. This saves all electrical systems connected to it.

If you want to know what a surge protector does, this post can be insightful and informative. In layman’s terms, electrical surge protection devices like spike busters are designed to restrict transient over voltages flowing into electrical systems downstream. This helps prevent damage to electrical components.

Very few people know what a surge protector is, and how it functions. A spike buster or a surge suppressor functions in two distinct modes. One is the Awaiting Mode, and the other is the Diverting Mode. In a normal voltage scenario, when power is supplied to electrical devices downstream, the SPD waits for a spike in voltage to occur.

Upon sensing and receiving an overvoltage, the surge protector changes into Diverting Mode. It diverts away the high voltage from critical electrical components that require high load. It also reduces the magnitude of voltage to a low level, which causes no harm to any electrical device. Lightning strikes create voltage magnitudes that exceed several thousand Amps. This is when a surge protector comes to the rescue act.

A spike buster or a surge suppressor works by transferring electricity from an outlet to all the electrical systems connected to it. When the voltage surpasses the normal levels, it will redirect the excess electricity to the grounding wire. This prevents high-voltage electricity from flowing into wires, which can cause irreparable damage to key home appliances and systems.

FYI, surge protectors are not the same as multiple power sockets or power strips available at stores. They don’t offer any sort of protection from voltage surges and fluctuations, though they look identical. So, when buying SPDs, learn to distinguish between these two devices, as it can be confusing. It should be labeled as a surge suppression device.

Technology in Surge Suppressors

Some common SPDs have safety components like metal oxide varistors (MOVs), avalanche breakdown diodes (ABDs), and gas discharge tubes (GDTs). Metal oxide varistors are standard in almost all surge suppressors that help protect AC power circuits from sudden voltage spikes.

The surge current rating of a metal oxide varistor (MOV) is calculated based on the cross-sectional area. Normally, the bigger the cross-sectional area, the higher the surge current rating of electrical equipment. In technical parlance, metal oxide varistors identify voltage levels and outputs. If the level is high, it will automatically redirect additional voltage. It also helps reduce resistance.

Similarly, the gas discharge tubes (GDTs) act identically like the metal oxide varistors (MOVs). At a certain voltage level, gas is a poor conductor. When the output voltage spikes above the accepted level, the electrical power ionizes the gas in the tubes, turning it into a good conductor. The current is transferred to the ground until it gets normal and becomes a bad conductor again.

Different Types of SPDs

There are three distinct types of surge protection systems. It can be categorized under Type 1, Type 2 & Type 3. Here, you get to know which type of SPDs should be installed at your place, depending on the load of equipment, device, appliance, or system.

Type 1 SPDs

This device is recommended for specific buildings, assets, commercial sectors, and industrial infrastructure where adequate protection is required from severe lightning strikes. It safeguards all electrical installations connected to it from heavy lightning. It discharges the current generated from lightning to the network conductors from the earth conductor. It is distinctly characterized by a 10/350 µs current wave.

Type 2 SPDs

This type of protection system is designed for safeguarding all voltage electrical installations. It is installed in individual electrical switchboards, preventing the transfer of overvoltage in the said electrical devices, thus protecting them. It is characterized by an 8/20 µs current wave.

Type 3 SPDs

These protection devices have low discharge capabilities. It therefore becomes mandatory to be installed as a back-up or support to Type 2 devices, and close to sensitive loads.

Appliances that Can be Plugged into Surge Protectors

• Laptops
• Desktops
• Televisions
• Washing machines
• Refrigerators
• iPhones & Tablets
• CPUs
• Home theater systems
• Stereo systems
• Digital devices with microprocessors

Final Words

In scenarios when there are huge voltage fluctuations, especially overvoltage issues with your energy service provider, a surge suppression/protection device can work well. Unlike voltage stabilizers which regulate the flow of voltage into certain electrical devices by maintaining a stable flow, SPDs divert excess voltage away from your house. In this way, it acts as a first line of defense against electrical power surges.

If you’re residing in North Texas, and looking for licensed, insured, and certified electricians in Plano, TX, you can contact a company like Copeland Home Services. It can provide you with comprehensive home protection solutions, especially when it comes to electrical voltage surges. Their inspectors and technicians arrive at your doorstep on-call, diagnose the underlying problem, understand your budget constraints, and offer a foolproof solution.


Q: How are surge protectors different from a power strip?

A: A surge protector or suppressor protects electrical devices, components, fittings & systems from overvoltage issues resulting from internal and external factors. Whereas a power strip only helps provide connection to multiple devices through a single board with 4, 5, or 6 power sockets.

Q: In case the MOV is burned out, will the surge protector still provide power?

A: Yes, even if the MOV is burned out, the surge suppressor or SPD will still be able to provide an electrical power flow, but can no longer protect an electrical device from future power spikes.

Q: Is a surge protection device mandatory for installation?

A: All homes and workplaces require an inexpensive, yet dedicated surge suppression device for high, as well as low voltage that helps negate the effects of overcurrents. Electrical and telecom circuits require adequate protection from voltage surges.

Q: What does 10/350 µs and 8/200 µs waveform mean?

A: FYI, a 10/350 µs waveform refers to a direct lightning strike to a conductor, whereas an 8/20 µs waveform represents an indirect lightning strike.

Q: What causes a voltage or power spike?

A: It can be caused by internal & external factors, such as lightning strikes during a thunderstorm, damaged wiring, downed lines, faulty circuit breakers, and frequent on & off of loads like air conditioners and refrigerators.

By Copeland Home Services July 10, 2024

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