So, Will an EMP Destroy Electronics That Are Off?

A powerful EMP event is one of the most devastating things that could possibly happen, and more worryingly also one of the most likely in the pantheon of super disasters.

laptop phone and laptop turned off

Be it created by a nuclear bomb or other devices, or even the result of powerful cosmic phenomena, an EMP can turn most electronics and any devices that require them, into useless bricks.

Of course, there are ways to protect electronics from EMPs. But how? Can an EMP damage or destroy electronics that are simply turned off?

Yes, EMPs can still damage or destroy vulnerable electronics that are turned off because they directly induce damaging currents or voltages into components like integrated circuits, diodes, and transistors.

Keeping your electronics turned off is not enough, by itself, to save them from an EMP if there are otherwise inherently vulnerable to it. That being said, it isn’t a sure thing that an EMP will destroy them since there are so many factors involved.

I’ll tell you a little bit more about EMPs, their effects, and how to protect your electronics from them in this article…

What Exactly is an EMP?

An EMP, the acronym standing for “electromagnetic pulse”, is a powerful burst of electromagnetic energy that can disable or even destroy electronics, and destroy or disable as a consequence any tool, machine, or vehicle that depends on those systems for function.

Whatever the source, these pulses can be extremely damaging to electrical systems and equipment. The sources of powerful EMPs (powerful enough to worry us) are few, but significant.

It’s widely known that lightning strikes can generate them, yet their disruption range is limited compared to other threats on our list.

“Sun storms” or coronal mass ejections have also been experienced in the twentieth and nineteenth centuries, and were potent enough to cause damage and disturbance over entire parts of the globe.

These gigantic bursts of plasma and the associated magnetic field are expelled from the sun, sweep across the intervening gulf of space and smash into our atmosphere as solar winds.

Though most are harmless, when these CMEs reach Earth, they can affect an entire hemisphere at a time. But the crowning horror of all, and the most likely source of a society-toppling EMP, is the detonation of a nuclear warhead.

Such a detonation produces an EMP that is immensely powerful, bit more localized compared to a CME.

The range of a nuclear EMP is increased when the weapon is set off high off the ground or in the upper atmosphere, allowing it to affect any area with a line of sight to the blast for many miles in all directions.

On top of the terror that is nuclear weapons, some countries also have access to EMP generator weapons which don’t require a massive blast but pack all of the gear-frying punch.

Called Non-nuclear EMPs, or NNEMPs, these devices are just as destructive and potentially even more effective.

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How Can an EMP Damage Electronics That are Off?

As we mentioned above an EMP works, or rather harms, by way of directly inducing voltages and currents into electronic components.

These components are often integrated circuits, like those found in most modern electrical devices, as well as diodes and transistors which are more simplistic but still vulnerable to a devastating EMP effect.

When exposed to an EMP the internal voltage of these components jumps up wildly, often well beyond specifications and tolerances, leading to their malfunction, damage, or even outright destruction depending on the intensity of the pulse.

This will occur whether or not the device is turned on at the time of exposure. An EMP has the potential to cause devastating damage and create sparks that could ignite fires.

It is highly likely to completely destroy electronics and storage media, and burn or damage any parts or materials that can carry a current.

In cases where shielding is present or a device is designed or specifically built to resist an EMP attack, it may only be disrupted or damaged. Otherwise, it is probably toast whether or not it is turned on!

Factors that Contribute to the Likelihood of Damage

The extent and probability of harm caused by an EMP on electronic devices which are switched off can vary significantly depending upon the intensity, duration, distance from the source of emission, and layout.

Devices near the source or ones that’re especially vulnerable may suffer irreparable damage. Ones further away or partially shielded could only malfunction or experience slight damage, or be repairable. Don’t forget that some components and subassemblies like connectors and power supplies may also be affected.

In short, the stronger the pulse, the closer it is, and the less shielding present, the greater the chance of harm to electronic components and systems.

Warning: Devices Connected to Power Grid are Even More Vulnerable

Just because your devices are still vulnerable when shut off does not mean you should not take steps to better protect them.

Specifically, any device that is vulnerable to an EMP and plugged into a power grid is at extreme risk of destruction.

Actually, anything plugged in will be fried! That is because the grid itself, the very power lines, are highly vulnerable to the effects of an EMP.

This means that even devices not directly exposed to an EMP but connected to a power grid in affected area may still be damaged.

This includes things that are otherwise safe from an EMP such as batteries that are connected to a charger.

If you are really worried about an EMP, make it a point to keep all non-essential gear and devices disconnected from all power sources. In other words: unplug it!

Radios, chargers, lights, generators, and any other devices connected to the power grid should be disconnected when not in use. This is especially important if you expect an imminent EMP attack.

For essentials that you want to keep powered and standing by, either have duplicate backups in storage or invest in real-time EMP protection systems for them.

Giving Your Devices Better EMP Protection

In this age where almost our entire lives are dependent on electronics, it is vital that we take precautions to protect ourselves from such disasters.

With the right measures in place, we can ensure the safety of our data and equipment even in the aftermath of a very powerful EMP.

The most reliable way to protect your electronics from an EMP is to invest in a Faraday cage, which essentially functions as a protective shield against the pulses.

A Faraday cage is nothing more than a metal enclosure, usually super-fine metal mesh, which will block out any external electric fields, thus preventing the signals from an EMP from entering it and damaging the things within.

It serves to block and conduct EMP energy harmlessly away from your gear.

These cages are available as pouches or boxes for smaller items, or for larger sizes as something like a tent or pop-up enclosure.

You may have to resort to constructing a full-fledged Faraday cage by using multi-layered sheets of aluminum foil beneath a nylon tarp, or else some other kind of conductive mesh.

You can also purchase EMP or surge protection devices that are designed specifically to defend powered electronic systems from EMPs affecting the associated power grid.

1 thought on “So, Will an EMP Destroy Electronics That Are Off?”

  1. How does a surge protector differ from emp protection if located at the circuit breaker panel?

    Can emp affect a modem and any electronics connected by CAT 6 cabling? Would it affect the electronics if the electronics (ie modem, router, stereo equipment, computer) were in a faraday cage or shielded with conductive cloth?

    Given the electronics get fried, would the house wiring fry also or would it be spared?

    Could a whole house generator be protected by emp if it was encased with chicken wire?

    Thanks for your help.

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