working on service during a storm!

[davedottcom]

About a year ago I was working on a regular 200 amp service, cutting in the homeruns, when a storm rolled through...well, there was a lightning strike that apparently was extremely close. A split second after the "Cracking sound of the hit" I actually heard a Loud "buzz" from the panel. It sounded like it came from the Main CB. Normally I wouldn't think too much about a sound like that coming from the Main during such an extreme condition except this service was not hooked up to any utility yet! The service had a 2" rigid riser and both ground rods installed, but no overhead connections had been made yet.

Not sure about what caused that sound, and now I'm paranoid about working in a Panel during any storms! (Which happen almost everyday here!)

Has anyone ever heard of any type of electrocutions from working on "Non-Energized" wiring during a lightning storm!?


Dave

 

[jimwalker]

Re: working on service during a storm!

My x partner had the exact situation happen in Naples once.He was a little worse off in that the rods were not in yet.He got a tingle.No you should not be working period on any wiring while it is thundering.Overheads make a Ben Franklin kite.And like it or not you were connected wireless for a split second,thats why the sound.

[ June 17, 2005, 05:43 AM: Message edited by: jimwalker ]

 

[zog]

Re: working on service during a storm!

OSHA has a rule for working in a substation during lightning storms, it says you are not allowed to work with lightning within a few miles, I cannot recall the exact distance, but I could look it up for you if you want.

BTW, Tampa has the most storms with 80 to 100 thunderstorms-with-lightning-days.

 

[George Stolz]

Re: working on service during a storm!

I have some decent tranmission lines running through my property. (In fact, if you stand in my front yard with a tick tracer, it lights up.

 

[charlie tuna]

Re: working on service during a storm!

george-------i would move!!!!

we were installing a lightning protection system and one of those thunder storms full of lightning moved in. i started to hear the roof spikes make a ticking sound----like they were disapating static electricity. we got off the roof!!! but i've been told by some installers this is normal?

 

[davedottcom]

Re: working on service during a storm!

Originally posted by georgestolz:I have some decent tranmission lines running through my property. (In fact, if you stand in my front yard with a tick tracer, it lights up.

George, did you try the Florescent Tube under the lines yet?
(It looks best if there's no moon light!)

Dave

 

[oceanaradio]

Re: working on service during a storm!

Has anyone ever heard of any type of electrocutions from working on "Non-Energized" wiring during a lightning storm!?
Dave [/QB]

Rare as it might be to be electrocuted in the situation you describe, it is possible for lightning energy to electrify inside wiring in these fashion:

1. Direct strike on the structure or nearby tree, pole etc. Powerful electromagnetic fields couple inductively and/or capacitively onto nearby conductors inside a wooden strcuture. Voltage division of bonding and grounding prevents the EMP from being a fire hazard, but electronics can burn in the worst cases, and suffer at least latent damage in most cases. "Tingling" might be the last thing someone touching it ever remembers, if they also make contact with a separate ground.

2. The SAME direct strike on a struture or nearby object also carries the return-stroke into the earth, and this saturates the ground with 100's of thousands of volts for a brief time. Grounding systems of the structure will reference substantial amounts of this energy UP into the structure, where again, proper bonding and voltage division prevents fire hazard, but other damage or shock hazard is possible.

3. Same Direct or nearby strike imparts high energy onto the power and telephone utilities, and either from EMP or coupling - it still gets onto the line. Lacking a good surge protection device at the utility entrance, interior surge protection systems will have their work cut out for them. The timing of these events, all of which can assault a structure from one lightning event, ranges from 2-5 microseconds for EMP, to a hundred milliseconds for a second, then third and even forth return-stroke to clear. Resonance and frequency of the structure, its wiring and grounding systems make every event like this different, just as the frequency of lightning has a range from nearly DC to over 100 megahertz.

Jack Painter
Virginia Beach, VA

 

[George Stolz]

Re: working on service during a storm!

Originally posted by davedottcom:
George, did you try the Florescent Tube under the lines yet?

Just did.

That's wild!

 

[charlie tuna]

Re: working on service during a storm!

actually, most sever lighnting strikes occur ahead of the storm. many victims don't even realize there is a bad storm close by?????

 

[petersonra]

Re: working on service during a storm!

I read once that often before a lightning strike one's hair will stand on end, and you will get that electric feeling.

The advice was to immediately lay flat on the ground, even if it is wet. Supposedly the liughtning strike will occur within a few seconds.

I wonder if this was good advice or not.

 

[69boss302]

Re: working on service during a storm!

Some of us don't have the luxury of such a warning system . If my hair started standing on end I'd be happy that I found a hair