2. tech-talk
  3. 1307849178

Surge Suppression vrs. Lighting and Power Spikes

OK,

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
eniac26
kijanki's avatar
kijanki
4,432 posts
 
Jeff_jones,

You can find confirmation on static built-up here:

http://www.dvb-brasil.org/how-to-ground-tv-antenna/

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".
gbart
290 posts
 
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.
kijanki's avatar
kijanki
4,432 posts
 
Gbart - other than crossing over gaps lightning can create big voltage differential between earth ground and neutral by hitting ground near the house.
jea48
4,530 posts
 
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
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?
.
kijanki's avatar
kijanki
4,432 posts
 
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.
More to discover