What Is a Surge Protector and Why You Need It

Close up of surge protector device

Electronic devices play an integral role in shaping our daily lives. Computers, printers, and sophisticated control systems such as PLCs and alarms surround us, but we often forget about their vulnerability to transient overvoltages. These abrupt voltage spikes pose a substantial risk, potentially compromising the longevity of our electronics and even causing permanent damage to them.

So, if you want to:

  • Learn what is a surge protector
  • How does a surge protector work
  • Is surge protector necessary

Then, read on!

Table of Contents

What Is a Power Surge?

Power surge manifests as a sudden surge in voltage occurring within fractions of a second. This spike has the potential to surpass normal voltage levels, leading to diminished performance or even irreversible damage to connected devices.

What Causes a Power Surge

The sources of power surge are diverse, ranging from the fury of lightning strikes and fluctuations in the power grid to internal culprits like faulty wiring or the cycling of household appliances. Each source brings forth distinct consequences – delicate electronics, in particular, face the threat of shortened lifespans, malfunctions, or complete failure. Therefore, a meticulous evaluation of potential risks becomes imperative, underscoring the necessity of surge protection.

What is Surge Protector

Surge Protective Devices (SPDs) safeguard electrical systems and are key components of protection against surges and power spikes. Strategically positioned within consumer units, these devices play a vital role in detecting and diverting excessive voltage away from sensitive electronics, including computers, televisions, and microwaves. This strategic deployment minimises the risk of damage and enhances the overall reliability of electrical systems.

Types of Surge Protectors

According to their function, surge protector devices can be classified into several types. Thus, to make an informed decision, you must be acquainted with the array of options when selecting a surge protector.

Type 1 Surge Protection Device

Distinguished by a 10/350 µs current wave, this type caters to service-sector and industrial structures equipped with lightning protection systems. Serving as the initial line of defence, it protects electrical installations from direct lightning strokes, effectively diverting the back-current from lightning that flows from earth conductors to network conductors.

Type 2 Surge Protection Device

Considered the first safeguard for low-voltage electrical installations, this variant, characterised by an 8/20 μs current wave, finds its place in every electrical switchboard. Offering protection against overvoltages and safeguarding loads, it stands as a crucial component in the defence against electrical anomalies.

Type 3 Surge Protection Device

Featuring a lower discharge capacity, Type 3 SPD complements Type 2 SPD, especially in proximity to sensitive loads. Marked by a combination of voltage waves (1.2/50 μs) and current waves (8/20 μs), it fortifies the defense against potential damage.

How Does a Surge Protector Work

SPDs typically operate in a high-impedance state without an impact on the system. However, in the event of a transient voltage or an abrupt surge in the circuit, these devices change from a high-impedance state to a conduction state (low impedance).

This transformation enables an SPD to divert surge currents either back to their source or safely direct them to the ground, effectively reducing the voltage to a safe level. Once the transient threat dissipates, the SPDs seamlessly revert to their original high-impedance state, primed for any unforeseen surges in the future.

It is essential to note that all SPDs have a lifespan, necessitating ongoing monitoring and maintenance.

Why You Need Surge Protectors

Surge protectors operate as silent guards, protecting your electronics and ensuring their longevity. Without them, the prospect of damage or complete failure during power surges induced by lightning or unforeseeable electrical variations looms large.

Investing in SPDs goes beyond mere precaution; it guarantees the protection of your electronic assets. Some of the key advantages of SPDs include:

Protect Sensitive Electronics

In an era dominated by sophisticated electronics, safeguarding these investments is paramount. SPDs stand as the frontline defence, guaranteeing that sensitive devices stay unaffected by abrupt fluctuations in electrical power.

Financial Investment

While SPDs may initially appear as a pricey investment, their cost pales in comparison to the financial impact following a power surge. Engaging an emergency electrician to repair multiple devices post-surge can swiftly surpass the preventive costs.

Lightning Defense

Amidst thunderstorms, SPDs act as the first line of defence, redirecting lightning energy away from vulnerable electrical systems.

Fire Mitigation

Beyond device protection, SPDs contribute to fire prevention by reducing the risk of electrical fires triggered by surges.

What to Consider When Choosing a Surge Protector

Choosing the right surge protection device involves the evaluation of several factors:

Assessing Power Surge Frequency

Start by evaluating the frequency of power surges on your property. If adverse weather conditions are frequent or if sensitive equipment is in use, installing a whole-home SPD may be the best option.

Deliberating on Equipment and Appliances

Consider the nature of the equipment and appliances in use. If you possess high-value electronic devices and appliances, the expense of hiring a professional electrician to install a whole-home SPD is a modest investment compared to potential repair or replacement costs.

Determine the Surge Protector’s Joule Rating and Installation Location

Consider the surge protector’s joule rating (a higher rating indicates that the device can handle larger power surges), the location where the SPD will be installed, and the exposure level of the equipment it will protect. This assessment aids in determining the required level of protection.

With these considerations in mind, you can confidently select a surge protector tailored to meet your specific needs, ensuring the protection of electronic assets against unpredictable power surges.


The vulnerability of our devices to power surges stands as an inescapable reality. A comprehensive understanding of the risks posed by voltage spikes and the advantages of surge protection devices reveals their indispensable role in safeguarding electronics.

From lightning-induced surges to internal electrical spikes, surge protectors serve as inconspicuous guardians, preserving device functionality and averting potential damage. Investing in these devices extends beyond caution; it provides assurance that our electronics remain resilient in the face of unpredictable power surges, ensuring uninterrupted connectivity in our digital realm.



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