Close Call

[prsmith777]

Lightning hit our neighbors roof last night. She said they were sitting around the fireplace when they heard an explosion that knocked one of their family members literally across the room. He couldn't hear anything after. Started a fire which was quickly put out due to quick response from fire fighters... about five minutes response time.

We have had two prior lightning strikes at our prior home (yes lightning does hit twice in the same spot). It burned down the house once and damaged it the second time.

Tripped a lot of breakers here but no damage. Strangely, it also turned on a metal detector in the attic which was beeping like a Geiger counter.

Other neighbors young kids were screaming for a long time after. Our 6 year slept through the whole thing.

 

[Starglow]

Lightning hit our neighbors roof last night. She said they were sitting around the fireplace when they heard an explosion that knocked one of their family members literally across the room. He couldn't hear anything after. Started a fire which was quickly put out due to quick response from fire fighters... about five minutes response time.

We have had two prior lightning strikes at our prior home (yes lightning does hit twice in the same spot). It burned down the house once and damaged it the second time.

Tripped a lot of breakers here but no damage. Strangely, it also turned on a metal detector in the attic which was beeping like a Geiger counter.

Other neighbors young kids were screaming for a long time after. Our 6 year slept through the whole thing.

Your metal detector story reminds me of what happened years ago when I lived in Florida. We had this reindeer stuffed animal that played Christmas tunes when you pressed on it's paws and one night during a lightning storm it suddenly started playing tunes. The next day we discovered that the windshield wipers on our car no longer functioned as well and the wiper motor had to be replaced. While it was not a direct hit in this case, but lightning storms can cause some strange things to happen for sure.

 

[jec6613]

Glad everybody is OK at least! Lightning and induced current is definitely no joke, I've had a strike about 100 yards from my home and the metal furniture I was touching at the time gave me quite the exciting jolt, and a couple of times lightning passed about 75 feet above my home to hit further away. I now have a checklist of things to check after a strike because it can cause so many weird behaviors, like how twice all of my dimmers needed to be reset, but the relay switches were fine (everywhere that code allows is on a lighting control system); or how a hardened lightning protected PoE switch with all of the Ethernet running through grounded (real earth ground) arrestor blocks blew all of its capacitors one time (and leaked electrolyte all over my hands when I went to take a look at it), but all of the attached equipment was fine.

There's a Motorola publication, "Standards and Guidelines for Communications Sites," that you can read up on how to do a full lightning hardening, it's well beyond what I considered reasonable for my home but it's an interesting read.

 

[prsmith777]

Update:

That lightning arced about 300 feet across the street and hit a tree in our front yard.
Lost a port on the router and an outdoor outdoor motion detector. Cameras survived.

 

[jec6613]

Lost a port on the router and an outdoor outdoor motion detector. Cameras survived.

Lightning struck trees are always so cool

So fun little thing about twisted pair is that it's designed to not care about induced current, at least in the original Ma Bell design. The pairs are twisted so that each receive roughly the same voltage, so that by the end of the (miles-long) run the output voltage remained within tolerances. It doesn't matter if I have an extra 1kV referenced to ground at the end, so long as the voltage from tip to ring is within tolerance of the 52.1V nominal. Using twisted pair for both signaling and power allows this level of protection, and better PoE cameras (and better is not a high bar to cross, think 99% of everything above $100 and most below as well) have their electronics isolated inside and are as resistant to induced current as a typical landline powered telephone, but with the much shorter runs, it would be very unusual to lose a camera to nearby strike and virtually all of those losses are from induced current on the PCB, not the Ethernet.

On the other hand, devices that are not dead-ends are susceptible to such damage as they do use ground as a reference voltage at some point. I'd bet the dead port was plugged into another switch or similar grounded device.

It's a very deep rabbit hole to go down obviously. For all of my inter-switch links I either use fiber optics, or short TwinAx runs if they're within 6 RU of each other and are ground tied anyway. It both prevents such a zap (and certainly prevents a cascade failure) and is lower latency, normally not an issue but with enough switches in your network they can add up.

 

[Starglow]

That tree is probably toasted and may not survive.

 

[prsmith777]

That tree is probably toasted and may not survive.

There are several like this in the neighborhood that survived. Hoping not to lose that tree.

 

[prsmith777]

Here is from another camera. Audio captured it well.

 

[Xeddog]

Tis but a scratch.

 

[CCTVCam]

Dig around your tree / cable. Fulgurite is worth a fortune and may pay for your router.

 

[TonyR]

So fun little thing about twisted pair is that it's designed to not care about induced current, at least in the original Ma Bell design. The pairs are twisted so that each receive roughly the same voltage, so that by the end of the (miles-long) run the output voltage remained within tolerances.

Unfortunately, as you know, Ma Bell didn't consult Mother Nature on the final design.....I have replaced literally scores of fax machines and analog and DSL modems on the end of POTS lines over the years due to nearby, induced ESD. In some cases it went own through the modem and into the Ethernet and got the NIC and sometimes, if an onboard NIC, the motherboard. In a few cases there was a RJ-11 surge arrestor which did its job and gave it up to save the protected device.

On my ever-growing list of mantras, platitudes and sage advice is..... "Lightning? It's gonna do what it's gonna do and go where it wants to go..."

 

[jec6613]

Unfortunately, as you know, Ma Bell didn't consult Mother Nature on the final design.....I have replaced literally scores of fax machines and analog and DSL modems on the end of POTS lines over the years due to nearby, induced ESD. In some cases it went own through the modem and into the Ethernet and got the NIC and sometimes, if an onboard NIC, the motherboard. In a few cases there was a RJ-11 surge arrestor which did its job and gave it up to save the protected device.

On my ever-growing list of mantras, platitude and sage advice is..... "Lighting? It's gonna do what it's gonna do and go where it wants to go..."

Oh definitely. Lightning is no joke! You'll notice though that the fried devices you mentioned were all externally powered and not line powered, so there was a path to ground through the device (even if only the neutral wire).

It's why when you lightning protect PoE Ethernet devices you're actually protecting the switch from the induced current, not the device, so you should put the protection in the equipment rack. Some even have a modest level of in-built protection so the bad outcome in most cases is a switch reboot - hope you remembered to write mem before it happens!

 

[prsmith777]

Discovered more fried devices:

Lost a Sonos speaker plugged in at the kitchen which was close to the tree. Speaker will not power on at all. This was plugged into a TPlink wifi switch which is fine. Other speakers closer to the tree are fine

Also lost one of two Dakota driveway sensors which were right next to each other.

Lightning doing what it wants