Time to go technical…’high-tech’ to be exact…let’s talk surge protection.
For this discussion surge protection will include the concepts of lightening strikes (LS), Coronal Mass Ejections (CME), and of course, Electromagnetic Pulses (EMP). While they do differ, they all can be a threat to electrical and electronic equipment. Additionally, I won’t go into detail on protecting small devices such as handheld radios since I have already covered that in the past. I will concentrate on covering entire systems such as home AC electrical systems and solar systems (both AC & DC sides).
As with all my articles regarding equipment/gear I define the mission, or job, that I want that equipment/gear to accomplish. For this I define it as…
“Reasonably, effectiveness & economically, protect our home’s complete electrical systems from damage due to electrical surges regardless of their origin.”
Also, when you hear me refer to a SPD, I am talking about a ‘surge protection device’.
Now that’s done let’s talk about risk management. As I have previously written extensively about risk management, it is determining the probability of an event occurring, and if it does occur, how severe will the potential damage be. Once those two criteria are properly assessed then proper mitigation measures can be identified and undertaken.
In my original article “Will we really be hit with an EMP?”, written in 2015 and updated in 2019, evaluated and stated both the probability and severity values. I originally set the probability at ‘very low’ and the severity as ‘nationally devastating’. Numerically speaking now I would go with 4 – 5 for probability (moderate) and 9 – 10 for severity (nationally devastating).
For the purposes of this article I put the CME events at a ‘moderate’ in severity and ‘low ‘in probability. And then for lightening I go with ‘serious’ in probability and ‘devastating’ in severity. And then somewhere in here I have to inject a healthy dose of reality. I don’t it is feasible at all to ‘harden’ my entire house and all associated electrical and electronic items against all possible surge events. I simply don’t have them time, the expertise, nor the money to do so. And honestly, I don’t have the desire to. I want to live in reality and not acquire a bunker and/or siege mentality out at the fringes.
So let’s talk the most likely of the surges involved with the most potential of severe damage…EMP.
EMP’s are a result of a high-altitude nuclear detonation. Modern nuclear devices that would be used in an EMP strike consist of three waves of energy pulses; E1, E2, & E3. Now, I am not going into intense details…it would make everyone’s eyes glaze over. There are plenty of articles on the subject if you want to get that far into the weeds.
EMP information, generally speaking…
- EMP devices are generally detonated high in the atmosphere so the damage can cover large areas of earth’s surface.
- The detonation effects spread out in all directions but the earth attracts most of the energy pulses downward.
- The higher the detonation the lessening of the pulse energy.
- The further away from directly underneath the detonation the lessening of the pulse energy.
- In North America the energy pulses are drawn more to the south of the detonation point due magnetic field and orientation to the equator.
E1 Pulse –
This first pulse of energy does most of the damage in systems. It is primarily high-voltage that does the damage. This first pulse of energy travels at about 90% the speed of light (about 168,000 miles per second) and peak energy is about at the 5 nanosecond mark.
Realistic Example: You are 250 miles from a EMP blast, that means it hits you in about 0.0015 seconds (15 thousandths of a second) but traveling at 168,000 miles per second, and once it hits you, the peak energy arrives in 5 nanoseconds. So once the energy hits you, the energy goes from 0% to 100% of peak withing 5,000,000,000ths of a second. And the pulse has passed you in about 100nanoseconds. Meaning you have to protect your systems quickly, approximately within a nanosecond, and for about 20nanoseconds.
The voltage that actually reaches a maximum of about 50,000volts per square meter. Meaning, if you had a 1 meter square steel plate sitting on the ground directly beneath the detonation point the steel plate would absorb 50,000volts. If what was struck was a normal 3-wire household service cable 100’ long from the electric pole to the electrical service entrance it would absorb about the same 50,000volts. Ironically, the amperage would only be less that 50amps for that same area…but only for far less than a second.
As you can see it is the absorbed voltage that will do the damage but it occurs very, very quickly. And that is why normal residential, and even commercial, surge protectors simply won’t provide protection…they can engage/react quickly enough…about 500-1000 times too slow to react to the incoming energy surge.
E2 Pulse –
This is the next energy pulse to hit…about 1000nanoseconds after the E1 strike, and 900nanoseconds after the E1 is gone. And the reaction speed required is about a microsecond. Yeah, slowpoke!
To get a grasp of this energy pules you can think in terms of a lightening strike. And also think of it in terms of DC 
voltage. The power can reach 100,000 volts and 100,000amps when it hits…depending on your relative location to the detonation. And surge protection devices such as Midnite SPDs can handle this kind of strike..essentially a lightening strike.
Here’s the problem…that same SPD would get burned out by the initial energy surge…the E1…so it is no longer available to handle the E2 energy surge…and your system is pretty sure to now damaged.
E3 Pulse –
The final energy surge is just plain weird! The energy surge is produced by the earth’s magnetic field being heaved about. And that surge can last from 10 – 100’s of seconds. To get an understanding of this pulse…think DC current. Unfortunately household systems, including power stations and transmission equipment are designed to handle AC current not DC current. That gets you a whole lot of burned out equipment.
Once again E1 pulses normally burnout SPDs that could have handled this E3 power surge.
Pulses Summary –
Whew! I am glad that is over. But the summary is pretty simple, 3 different pulses of energy, all 3 can destroy equipment, and the first pulse is the worst and generally destroys any device (SPD) that could prevent damage from the 2nd and 3rd pulses. And yes, generally speaking almost all SPDs in use today can’t handle the E1 pulse. So you’re screwed right? Ah, no.
Remember, most common SPDs can’t protect against an E1 pulse…they burnout with all your other electrical/electronic gear. But, most common SPDs are fairly inexpensive…about $125 – $150 range for Midnite SPDs. The commercial grade SPDs can hit $300, but they still are too slow to protect against the E1 pulse.
That means something rather simple…You gotta find E1 protection if you are going to be worried about EMP protection. If you are going for less protection against energy pulses, such as lightening protection, then a Midnite Solar SPD or the more expensive Siemens FS140 are great options.
Next comes what I do!
NOTE: In Part #2 I will give links to various products that I personally use and believe in. And if you purchase a product through one of those links I will make a bit of money…from 2% – 15%. The money I make from any of those purchases will go towards a new battery for my solar system. And I can offer a $50 off coupon for the #1 EMP surge protection device!!!
< click here to read Part #2 >
Related Articles –
- Protecting your Radio from an EMP: Part #1
- Will we really be hit with an EMP? (part #1)
- Threats, Risk, Matrix, Mitigation: Introduction
