Lightning fried my scanner
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mmckenna
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bill4long
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Doubtful you had a direct hit. Those are always completely devastating to everything in the chain. Average 300 billion coulombs of electrons in a bolt of lightning. Imagine 300 billion watts for one seconds. That's what we're talking about, except it's more concentrated than that because the strike happens much faster than a second.
Grounding your antenna will just make it more likely, not less, of a direct hit. The only thing you can do to prevent destruction of equipment during a lightning storm is to unplug everything: your antennas, your radios from the AC power, and get your antenna coax as far away as possible from any electronics. Things like polyphasers are useful for indirect hits. But not direct hits. I would not rely on polyphasers if you actually care about your equipment.
For those curious about an "indirect hit": when lightning strikes, it often hits an object, like a tree or street light pole or an antenna, but the strike also throws a tremendous among of electrons around (static electricity) in the proximity of the strike. That field of electrons can do all kinds of damage, and things like polyphasers and grounding can mitigate damage from the electron field. But they are useless for a direct hit.
Unplug your stuff during lightning storms.
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RFI-EMI-GUY
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I have to laugh about grounding to a fence post. Over a year ago 4/15, here in CFL, I was sitting at my desk and out of the blue, lightning struck barely 10 feet from where my window sits. There is a huge camphor tree there and initially I thought it was struck. Turns out it was a metal fence post, the green type used for a wire fence, that, months before, I had casually stuck in the ground right next to the trunk of the tree. It had an orange pvc protective cap on it, now that cap was blown to peices. The lightning passed under the tree, blew open my lawn irrigation pipe, travelled the low voltage sprinkler wiring, blew the electronic timer off the garage wall (about 60 feet away) . Current entered the branch circuit in the garage and caused damage elsewhere in the house. A surge protector at the electric meter would not have prevented this.
My main utility is grounded on the far side of the house. To prevent this from happening again, I have built a surge protector for the new sprinkler timer and have grounded it at the branch. However I am going to need to complete a ground ring completely surrounding the house to ensure an equipotential for this secondary entrance.
Thankfully no radios were damaged by this blue sky lightning strike. My old Sony Bravia in the bedroom got zapped on the HDMI along with other devices on the HDMI inputs. GFCI s were damaged and stuck in the ON condition. One was for the pool light, which months later seems to have a current leakage.
My main utility is grounded on the far side of the house. To prevent this from happening again, I have built a surge protector for the new sprinkler timer and have grounded it at the branch. However I am going to need to complete a ground ring completely surrounding the house to ensure an equipotential for this secondary entrance.
Thankfully no radios were damaged by this blue sky lightning strike. My old Sony Bravia in the bedroom got zapped on the HDMI along with other devices on the HDMI inputs. GFCI s were damaged and stuck in the ON condition. One was for the pool light, which months later seems to have a current leakage.
I learned from reading here.
That's what I did, along with below.
Yep.
You can pick up stuff pretty far away depending on the antenna.
higinbotham
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A little history
The Lightning Rod: A Not-So-Shocking Invention | Pennsylvania Center for the Book
siarchives.si.edu
The Lightning Rod: A Not-So-Shocking Invention | Pennsylvania Center for the Book
Lightning & Lightning Rods
[edan-image:id=siris_sic_12023,size=300,left] In 1832, Professor Joseph Henry gave the first in a series of lectures on chemistry, and introduced the topic by discussing the role of basic research in technological advancement.
higinbotham
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There are several other references for dealing with lightning.
Certain codes and standards must be followed when lightning protection systems are installed. Standards and sources are listed below:
LPI-175: The lightning protection code, published by the Lightning Protection Institute.
NFPA 78: National Fire Protection Association Lightning Protection Code.
ASAE EP381: American Society of Agricultural Engineers, Engineering Practice.
96AUL: Requirements for Master Label for Lightning Protection, developed by Underwriters' Laboratories.
NASD - Lightning Protection for Farms
Lightning, one of nature's most powerful forces, can cause a great deal of damage, particularly in a farm environment. A lightning strike can start fires in buildings, damage electrical equipment, and electrocute humans and livestock. Losses from lightning can be very costly. Replacing buildings, e
G7RUX
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No, a fence post isn’t good enough. Proper grounding, complying with codes, surge arrestor on the feeder where it enters the property, again properly grounded and disconnect in a storm if at all possible.
Take care and do it properly as lightning can do a LOT of damage and any amount of protection likely won’t stop damage with a direct strike.
zlamb0002
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I need to go about 60 ft to connect to the intersystem bonding termination to properly ground everything. Does it have to be bare copper or are there other options?
mmckenna
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Does not need to be bare copper.
Speaking of lightning. We had an insanely violet thunderstorm yesterday around 7PM, with 40-50MPH wind and 4" of rain in a hour or so. My bosses house got hit with lightning and blew the copper tubing out and they lost all the freon. Lightning was right on top us.
wtp
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yep flash-bang. fblaansgh, flabangsh ?
RFI-EMI-GUY
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You will need a ground rod driven approximately every 16 feet of the 60 feet assuming an 8 foot length ground rod.
zlamb0002
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I have everything for my grounding planned out but I was wondering where the lightning arrestors go. Or do I just need to use one polyphaser?
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mmckenna
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You need protector on each coaxial cable right where it enters your home.
In a commercial installation, there are usually ports in the wall where the coax enters. There is also a large copper plate on the inside wall. Coax comes in and connects to a Polyphaser. Polyphaser is attached to the large copper plate, which is grounded with heavy cable into the grounding network. Another length of coax is connected to the protected side of the Polyphaser and runs ot the equipment.
It gets to be pretty extreme, but in most installations, the coax jacket is grounded at several points, usually at the top of the tower (or where ever it's connected to the antenna), at the base of the tower, sometimes a point between the antenna and the bottom of the tower. Usually grounded outside the entrance point to the building.
On commercial/public safety radio sites, it's a complex process.
for what you are doing, just make sure you have a proper ground rod near where the coax enters the home and everything is properly grounded/bonded.
At this point I think its good to look back at post #8 and realize with all the grounding you are doing you will not be able to protect your radio from damage from a direct hit with a residential electrical system. I would still disconnect the antenna lead and keep it far away from anything if there is a chance of a lightning storm. You might even consider unplugging everything in the house when lightning is approaching as its common for TVs or stoves or clock radios, etc, to get destroyed from a direct hit.
If you have had this to begin with !
zlamb0002
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Do you attach this right before it comes in the house or at the antenna when the coax cable starts?
The OP says "lightning hit my antenna" and that device won't do anything for that. The problem is not the voltage across the center conductor and shield of coax, which is what that devices might protect. The real problem is the voltage potential between the coax and the power/ground system that the scanner is plugged into. The finest coax lightning arrestor made does nothing for that as the strike will simply flow down the coax, through the scanner and its power cord to the electrical system and its toast.
Even if its a portable scanner running on internal batteries sitting on a wooden table, the strike will most likely flow down the coax to the radio and arc to something else toasting the scanner in the process. Lightning can travel many miles getting to your antenna, so a few extra feet inside your house means nothing.
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