Surge Suppression vrs. Lighting and Power Spikes


Here is something I have thought about on many occasions while jamming out and then being rudely interrupted by an overhead lightning storm. Should I continue my session while the storm is overhead or should I switch everything off and wait until it blows over before continuing? I have chosen to switch my equipment off but leave it plugged into the wall.

Is powered on audio equipment any more vulnerable then powered off or in standby mode audio equipment during a lightning storm or power grid spike? I mean if your house gets hit by a direct lighting strike that was the result of having an old school TV antenna on your roof or if the power station down the street gets zapped the wave of electricity is coming your way weather you like it or not, correct?

As an example, if we take 3 houses that are all on the same power grid into consideration during said event, does the house who happens to be drawing the most current at the time of the event have a higher likelihood of being the one who gets chosen by the power spike as it's target for discharge? The term magnet comes to mind as another way of thinking about it.

Now I would imagine this spike has the potential of being very powerful. I have seen some numbers on the web stating that a direct lightning strike can generate anywhere from 1000 to 100,000 AMPS of juice. If these numbers are even somewhat close to being accurate then even the fanciest surge protection/power distribution device isn't going to save your equipment.

If your lucky enough to have the direct hit occur at the power station down the road then I assume the power company has some kind of buffer device that absorbs a large portion of this electricity before it reaches your house but this is just an assumption. If they do have some kind of buffer then maybe your surge protection device has a better chance of survival since the impact would be greatly reduced; maybe even to the levels that most surge protectors found in the home can tolerate and maybe not.

It almost seems that the only real safe bet would be to fully unplug your power distribution device from the wall since we obviously can't predict how the power spike will arrive either thu a direct hit or a possible buffered hit.

I'm curious to know what the general consensus is on this topic and what others do when faced with a storm overhead?

Please feel free to post your thoughts..Thanks
Unplugging everything you can is the best bet. There is protection (arrester plus other?),on the utility end that should transfer most of that strike to ground. But, if the pole or one in your area gets hit, there is some spike voltage(when their stuff works right) that does get through. I would not count on any devise for in the home as a sure thing for even this type of spike. If you want to risk leaving your stuff plugged in, using a quality surge protector may help, but not for sure. A direct hit to your house is the worse risk for your equipment, and possibly occupants. I've seen pictures where a lightning bolt blew right through the roof and struck an object to complete its path. One was a sink (going for metal pipe?), that half was missing, another was a range with a big burn on the corner of it going by memory. Lightning does things that are odd. I've seen lightning strike the ground right next to a telephone pole! So with all that said, unplug. After seeing that shattered sink, you could see why they say stay out of there during a storm. I imagine if you Google lightning strikes, or check it out on Youtube, you'll probably see some interesting pictures. Anyone might give it more respect too, after seeing the pictures, or videos.
Eniac and Hifihvn, you both have it right. If lightning is prevalent or imminent, unplug. Also, if at all possible, purchase power conditioner/surge suppressor that provides warranty against lightning damage and keep your homeowner's insurance upgraded because despite your best efforts you may still be hit.
I experienced this very event several months ago. My wife and I were outside when several ground surface lightning strikes hit in advance of any rain. As I ran inside to shut down electrical gear and unplug, one particularly violent strike hit a couple of blocks away.

My audio gear was not operating and was properly connected through the power conditioner. Three components were knocked out entirely. I speculate that damage came from either emp or a power surge as you describe, carried by the electrical service.

The company replaced all three components, and also the power conditioner under warranty.
Switching off does nothing to protect from lightning. If you value your equipment, unplug it from the wall.
I use power conditioner with very tight and non-sacrificial over/under voltage protection but still unplug when at home during thunderstorm.

People believe that grounded antenna attracts lightning. It is exactly opposite - ungrounded antenna attracts lightning since it is floating (separated from the circuit by input transformer) and charged by the friction of the wind to very high static voltages making your house looking (electrically) like a skyscraper.

There is no way to protect against direct hit (other than unplugging) since there is no protection or even wire that can carry 1-foot wide plasma. Again - unplug.
Unplug, unplug is the only safe way to go. Some think that switching off the panel circuit breaker works also, but that is not true. You need to physically remove the line. All else does not work.
I always unplug when not in use. Overkill maybe but what's not in this hobby? During any storms I power off and unplug.
People believe that grounded antenna attracts lightning. It is exactly opposite - ungrounded antenna attracts lightning since it is floating (separated from the circuit by input transformer) and charged by the friction of the wind to very high static voltages making your house looking (electrically) like a skyscraper.

I'm guessing that why the NEC (national electrical code) now requires you to bond it with the homes electric ground (if memory is correct), to lesson any static buildup that my attract a direct lightning hit.
I should have said, all of the ground rods(antenna included), need to be bonded with your homes electrical grounding block, if my memory is correct. Years back, I think you could just use an arrester and ground rod alone, without the all of the bonding.
"People believe that grounded antenna attracts lightning."
I'm one of those people. Lightning follows the path of least resistance to ground.
Unplugged is safer than plugged, but why bother at all? I live in the midwest in an area that is prone to seasonal thunderstorms and the tornado sirens have to go off before I'll unplug. I leave the equipment running 24/7 and half the times a storm comes through I'm not even home. Am I living dangerously? Hardly! I imagine the added risk is akin to that of driving in a rain storm vs. driving on a sunny day. A measurable added risk, but something you don't think twice about.
Its also worth mentioning here that adding a whole house lightning and surge protection unit to the incoming service lines and installed at your circuit breaker box will provide some additional protection. I use that and an individual surge protector in front of the equipment. Unplugging is the only sure way to protect your equipment. Most of the warranties on damaged equipment can require you to send the units in for repair/replacement which takes a long time. Also, it is worth protecting all the sensitive electronics in your house, including the microwaves, ranges, refrigerators, washer/dryer, and all the myriad things that have tiny chips.
I live in a major lightening area in FL. unplug your equipment to be safe and unhook the antenna (Indoor or Outdoor) from your tuner. If you ever have a direct hit, no amount of protectors are going to help you. Best to be carefull. Good luck to all.
"Lightning follows the path of least resistance to ground."

That's true but if antenna has to be there grounding ads few feet to building but not grounding can add much more making it higher than surrounding trees and street lamps.
Check out the video on lightning, a little down the page.


Start with whole house surge protection::

Leviton makes a similar device for the main panel. If I still lived in Florida, I'd have one installed immediately.

Unplug. yes...... the voltage induced in a line by lightning will bridge a switch even if 'off'....
I live in SW Florida where during the summertime there are thunderstorms like clockwork everyday around 4pm. Caused from the heat of the Gulf waters. It is one of the highest lightning strike areas in the country. Since moving here 20 years ago, homes I have lived in have been directly hit twice, blowing out yard lights, blowing out fireplace, frying phone lines and alarm system. I don't bother with any surge protection - I just plain unplug, everyday in the summer. It's a PITA, but I can't afford to have my equipment fried, so I do the best protection possible - no connection. The main downfall of it is, trying to find decent power amps that don't take 2-12 hours to warm-up to sound worth a darn. I'm still looking...
Yep, Troy, I hear you. Florida Flicker and Flash was the power company.
I lived in Florida, both N.Miami and Tampa until I was 20 or 21, so I never even rented, let alone bought a house.
But for darn sure, i'd have whole house surge protection, in addition to what is your usual practice.
After all, you can't unplug everything. Your fridge? a couple computers and maybe a clock radio / Ipod dock?

Be careful with the unplug routine, too. Current can arc from the plug to ground at the peak of potential, maybe.

If I lived in tornado alley, I'd follow the same routine.
I agree with the above responses stating the only true protection is to unplug your equipment. The purpose of grounding tv/radio antennas is to prevent them from having a neg or pos charge that would attract lightning. These grounding systems do nothing to dissipate the electricity from a lightning strike, you would need a grounding cable about 6 ft in diameter to even get close.

If your house suffered a direct lightning hit, the surge of power would travel through your house's electrical system wreaking havoc with any components and appliances connected to it. Surge protectos would be fried and be of no use against such a surge. So make sure your antenna is grounded and unplug any components and appliances you value during storms.

There have even been cases where lightning traveled out of tv screens. You'll need lightning quick reflexes ( actually a bit faster than lightning quick) to avoid those. Thanks.
"The purpose of grounding tv/radio antennas is to prevent them from having a neg or pos charge that would attract lightning."

I don't think this is true but am looking for reference material to verify or dispute the concept, not arguing.
When you ground you intentionally make the antenna negatively charged relative to the atmosphere, that charge difference is why lightning wants to find ground in the first place. An ungrounded antenna would seem unlikely to be as negatively charged as a grounded one, if it were positively charged that would make it less attractive to lightning.

"These grounding systems do nothing to dissipate the electricity from a lightning strike, you would need a grounding cable about 6 ft in diameter to even get close."

They do create a path of least resistance which improves your odds of reduced damage to property or personnel. As noted, the cable will be overwhelmed but should help establish an ionized air (ionized = low resistance) path to ground along the way.
You could say that a tall tree does nothing to dissipate 30,000 amps or so of lightning current, but sometimes it does protect lower things in its vicinity by establishing the initial (or one of the initial) paths to ground.

You can find confirmation on static built-up here:

My antenna isn't grounded since I'm lazy but it is required by law (NEC). In case of lightning damage insurance won't pay me a penny. Problem with grounding is that it has to be done (to be legal and insured) with at least gauge 10 wire to ground rod with bends of no smaller radius than 6".
I only read the first two paragraphs of the OP. When there is lightning or threat of it, I always unplug my system. the small gap in a power switch or breaker will not stop lightning. No kind of surge protection is a match for a direct lightning strike. Unplugging is the best insurance.
Gbart - other than crossing over gaps lightning can create big voltage differential between earth ground and neutral by hitting ground near the house.
Problem with grounding is that it has to be done (to be legal and insured) with at least gauge 10 wire to ground rod with bends of no smaller radius than 6".
06-13-11: Kijanki

You are correct on the size of the wire. #10 awg copper or #8 AWG AL minimum. NEC 2008 (810.21 (H)) I would never use AL.....

The way I read it if a separate earth grounding electrode is used the grounding electrode, ground rod, shall be connected to the main electrical service grounding electrode system with a bonding jumper no smaller than #6 awg copper or equivalent. (NEC 2008 810.21 (J))

The important thing here is the antenna grounding conductor ends up being connected to the main grounding electrode of the electrical service of the premises, end result.....
Is that the way you understand it?
Jea48 - I'm not sure. I think that if house has already grounding rod they allow to use jumper but if it doesn't then ground rod need to be placed.

There used to be a lot of antennas around (none grounded) replaced last years by cable or satellite. I'm the only one with antenna on the roof now. I like basic programing and am getting it OTA in HD for the last 10 years. I could possibly move to cable but I watch too much TV the way it is. Pretty much like giving drugs to an addict.
I would bet most residential earth grounding electrodes are inadequate when it comes to lightning protection.

If memory serves me right the maximum electrode to earth resistance of 5 ohms per IEEE.
Jea48 - one of our customers returns heavy current transients of vector drives to building frame. It works much better for them than ground rods they had before, because earth had tendency to be dry and constant watering them was a big hassle. Unfortunately I don't have metal frame and would have to use ground rod hoping that thunderstorm will bring rain first.
Yes, that is a problem with ground rods alone. Might be it's part of the reason for the bonding to the homes ground too. Plus less chances of arcing over I imagine. I saw that link Jea48 posted and couldn't find it again. Thanks for posting it. Good info. I guess they've learned a lot from those experiments, with shooting those rockets up into the clouds in Florida. A lot of those skyscrapers have some big thick steel plates under them, where it's nice and moist, plus all the contact with the moist ground must be the reason they take all those strikes, without any problems. Still better odds with a wire with a ground rod will direct a lot more toward the ground, instead of coming straight down through the roof I would think. Years back before cable TV, our roof antenna was on a tripod, with a 4 gauge solid copper ground wire,and it still had me moving away from that end of the room below it, just in case, during a nasty storm. Another link to read. []
A Youtube link to watch if somebody else didn't post it first.
Better slow motion video.[]
Wow, allot of good info and experiences posted here. Thanks for sharing your thoughts on this topic. I think I will take the extra steps required to fully unplug my equipment when the next storm blows in as it just isn't worth the headache of dealing with fried equipment after putting so much time and money into fine tuning my system over the last few years.

I think the added wear and tear that I will be placing on my pricey power cables by plugging and unplugging when a storm occurs will be worth the piece of mind knowing my stuff is safer.

At the end of the day if I am unfortunate enough to be one of those people that take a direct hit thru the roof of my house and the lightning ball happens to hone in on my amp then I will take that as a sign that it was time to upgrade anyway.

Thanks again