Industry Forums > Wireless Service Providers > Lightning damage pics

Lightning damage pics

Conduit coming into main panel - Next size KO is burned out completely and conduit is loose

Conduit entering bottom of main panel

Conduit entering side of main panel

4/0 coming into building - 4/0 is connected to chemical rod, bare copper runs up wall to apparent suppression unit

Where bare copper touched electrical conduit

Where bare copper touched electrical conduit

Conduit entering a sub panel

Conduit entering top of Main panel - same conduit as first picture

Conduit entering Sub Panel

Scorch marks on panel cover

Arc marks on inside of box

Suppressor?

Outlets where their equipment was plugged in

Conduit entering side of heater

Conduit entering side of main panel

Conduit entering bottom of mail panel

Conduits entering bottom of Main panel

Meter base and #8 bare copper running to 3/8" ground rod

Ground rod for Electrical service, phone nid is bonded here as well. To the right is the 4/0 enteringthe building.

One of the connections they left behind

multiple isolated ground rods creating potential, the conduit connections were not tight nor were they properly bonded.
--
Lack of Preparation on YOUR Part does NOT Constitute an Emergency on Mine!

reply to Rhaas
Holy hell.

Lack of single point bonding.

I can preach this all day long, bond, bond, bond.

A lot of good that fancy chemical rod is doing. You may (hard to say) have a low impedance ground there, but if everything is not bonded correctly you'll get what you see here. I have seen it first hand personally, and now others can see it as well.

EPIC FAIL.

Rhaas, you need to bond the hell out of everything. I bet the site is built using set-screw conduit couplers? If so you need to use #6 to bond EACH side of that conduit as it passes in and out of the coupler, conduits running into 4-square boxes, etc bonded before they enter the box somewhere, that electrical cabinet needs bonded, and you need to get a better utility feed SPD, again, bonded.

This all gets bonded to an internal building halo, that runs around the room, the halo is not continuous, rather, separated by a foot at the furthest point AWAY from the MGB....

There are also special methods used to route the bonding conductors.... Everything must flow back to the MGB.

ALL bonding connectors must be done using irreversible high compression crimps (CTAPS and lugs) and UL Listed conduit clamps (harger sells them).

Compression type conduit connectors and couplers are not required to be bonded across, just need to bond the main panel(s), in your case, this is NOT the case.

Also need to install an MGB, EGB, and TGB. Bond it all together, bond to the chemical rod.

Drive galvanized rods at each guy anchor, bond the guys down to the galv rod using TINNED (not bare CU) solid #2 and use only tinned split bolt hardware.

Install a building ground ring and bond that to the tower ground system, I'd need to know building dimensions to tell you how many rods to drive... It'd be better if I knew soil resistivity factors and then I could just calculate you how many rods will be required to get down to 5Ohms or less for the entire system....

Get someone to measure that chemical rod as well using the three-point fall of potential method. And I would still look into installing odd-angle radials, to help drag the strike away from the tower.

If we had this site presented to us, it would probably cost you are looking at around maybe $15,000 to $18,000 in labor close to that in parts.... Factor maybe $25,000, and even then I can't tell you if that is a good solid number.
--
"No job is so important, and no service is so urgent that we cannot take the time to perform our work safely."
-- AT&T, Your World, Destroyed.
--Safety One Tower Rescue Certified
--LLigetfa:"Wimax is like teenage sex. Everyone talks about doing it."

reply to Rhaas
Oh yeah that wall heater above the one sitting on the floor, bond that too....

reply to davidg
Yep. If it conducts, bond it.

Imagine "Emperor Palpatine style lighting bolts out the fingers" type of incident.

"I bonded everything in the site but somehow i have huge scorch marks on the file cabinet and everything across from the cabinet!"

*cue high-voltage transmission line humming sound*


--
"No job is so important, and no service is so urgent that we cannot take the time to perform our work safely."
-- AT&T, Your World, Destroyed.
--Safety One Tower Rescue Certified
--LLigetfa:"Wimax is like teenage sex. Everyone talks about doing it."

The multiple ground rods and the grounds not being bonded/single point ground system were the two that jumped out at me quick. There are two chem rods at this site and we tried to check to see if the rods were bonded using our cable locator but since we are unable to disconnect from the chem rods we couldn't trace a thing. I hate the idea of disturbing the rods as they are obviously matured.

Heaters and AC are blown, I'll probably strip out the heaters anyway (there are two units in the building).

We talked about the compression/set screw connectors at AF. Going back through when we had our CO's inspected to RUS standards - they call for an airgap on any metalic conduit entering the main panel ie conduits are not to be bonded to the main panel but to the ground window.

Building is maybe 6'x8' or 6'x6'. Soil composition is SAND. The building & tower sit on a slight rise so I plan on using that to my advantage on installing radials ie run the radials downhill rather than uphill.

The thing that Splitpair mentioned in passing is that you'd be surprised as to what becomes conductive during a lightning strike - All those metal boxes bolted directly to the cinderblock is a no-no.

Probably the first thing I plan on doing - as much as I hate it - is to dig up around one of the chem rods and determine if they are bonded together or not. The rods IMO are too close together - maybe 15' apart.

Given the layout and the fact that the tower is ~5' from the building I will likely use a single ring to encompas both the tower and building, If I try to put seperate rings they will be too close together. I will drop probably three radials N, S and W, to the East is a gentle rise also the end of the property.

I will pop in a MGB inside the building and set two other bars, one at the base of the tower for the cables and one just inside where the cable enters the building for the suppressors.

Haven't really though about a halo too much, just due to the size of the building. By the time i get a rack and cable tray in there I more or less will have a pseudo halo anyway. The only other thing for sure that I need to bond is the metal doorway.

Oh and our cabinets in the CO's are bonded to the MGB

reply to Rhaas
PISS....POOR....Bonding and grounding. WOW!

Need me to come down there and fix it for ya?

Any conduit entering through an eccentric or concentric knockout hole should be independently bonded. The best way is a bonding bushing for a site like this.
--
Looks like Reverend Wright got his wish - God Damn America.
Nancy Pelosi - House Minority Leader 2010
Harry Reid - Senate Minority Leader 2010

reply to Rhaas
A lot of installers don't like those multiple size knockouts and won't use them. They prefer to drill or punch their own holes.

While the knockout provides a poor ground path, they should not be relied upon for good grounding. The reason many installers don't use the knockouts is because they fail under physical pressure, not because they fail under lightning induced current.
--
Strange as it seems, no amount of learning can cure stupidity, and formal education positively fortifies it. -- Stephen Vizinczey

Yea that storm was pretty rough. Our site in springfield that has service from a WISP lost the canopy backhaul tower side. Verizon lost some stuff on the same tower also.

reply to Rhaas

reply to AMD Phreak

reply to lutful
Nice Googling, by the way do you happen to know a member by the name of Doc Olds?

Wayne
--
If you cannot fix it with a buttset and some beanies you're not a technician.

reply to Rhaas
Yesterday as that front with its tornados drifted through here we had a 135' monopole take a direct hit and other than a blown port on the Nokia and a matching SmartJack card no other damage to the site.

Actually if you look carefully you can see the other SmartJack's in the NCTE while thoroughly smoked and sooted up are still in sync and carrying traffic.

reply to nunya
Also if you note carefully it appears no one took the time to clear the paint down to bare metal from the area where the conduit connectors and lockrings make contact with the cabinet.

That paint should have been removed, the metal cleaned and after the lockring is properly tightened the area greased to prevent rusting.

And as you correctly pointed out a grounding bushing should have been used with any concentric KO.

Wayne

--
If you cannot fix it with a buttset and some beanies you're not a technician.

reply to Splitpair

reply to Rhaas
..... reading that GDT manufacturer PDF further, it seems the two little dots you see on the top of each GDT are test points.

So, after a major surge event the site technician can go down the row and test each GDT with a meter and probes to see if it is still good, without having to physically pull it out and possibly interrupt the customer datalines.

=====================

Although used mainly for telco hardware I believe these are also effective for coax lines.... (googling) ah yes here we go...

Coaxial Protection - Gas Tubes
»www.citel.us/coaxial_types_gas_tubes.html

=====================

If I am to do anything with my shoestring WISP, I am going to have GDTs protecting all the customer and tower equipment, in addition to bonding and grounding.

.
--
CenturyLink remote pedestal: RUBY, 10 miles west of Gilman, WI
»Rural Century Telephone remote terminal unit
»Name of this pole-mount outdoor telco canister?

reply to Javik