Lightning Strike(s) and Damage

Started by MountainDon, July 22, 2014, 01:55:43 PM

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Adam Roby

A few years back I was renting an apartment and there was an electrical storm that hit close enough to fry our microwave as well.  It was a small apartment with very few outlets so I had power bars more as splitters for most of my electronics.  They all blew... I heard the pops and smelled the burning.  I managed to crack one open and there was a condenser or capacitor across the poles that blew on every single one.  The microwave was plugged directly into the wall.

I am wondering if surge protectors would have helped.  Power bars, or even the type that protects the entire electrical panel.  (I see them a lot on Canadian renovation shows, not sure how many homes are protected by them). 

UK4X4

Sorry to hear of your damage,,,but it could have been a whole lot worse, at least the cabins still there !

Lighting is so powerful it finds its own way to earth, whatever protection systems you have, its more than likely it would just bypass the breaks.

Leaving gear unplugged is a solution to your portable gear

I think I have a pic somewhere of a lightning protected oil field site that I worked on in Colombia, the site was literally surrounded by 6 meter high steel tree things with multiple spikes and large ground wires for each one

here you go, they were like these, seemingly lightning likes spikes.....so you have a bunch for it too choose !


Dave Sparks

Yes WEIRD !  Some of the weirdness is explained in science and it is called latent damage. The device may still work normally but it has been compromised and either time, heat, cold, or another surge may destroy it for good.  We use to perform  latent damage testing for semiconductors and you can see the damage with xray and other testing.

As for physical disconnect of the array (8 feet +) there are rated plugs or connectors. The other way is just cut the cables at the JB and reconnect the set screws after. If I were leaving unattended for a long time, I would consider this. The surge protection is not as good and I always believe it is for the day you are at work and the strike hits.

On the boat we had regular sacrificing to Poseidon! I am going to add wild fire to the list with lightning and hurricanes. The DC 10 made 11 trips over my house yesterday to a fire up in Yosemite. It is nice to be on the upper side of the dirt.
"we go where the power lines don't"

MountainDon

Quote from: Dave Sparks on July 28, 2014, 09:51:18 AM

As for physical disconnect of the array (8 feet +) there are rated plugs or connectors.


Anderson power poles?
Just because something has been done and has not failed, doesn't mean it is good design.

MountainDon

The more I think about it the more I like the idea of having the ability to easily disconnect the feed from the PV panels to the CC, etc. I stress easy, as my wife is not going to want to get in there with a tools to reconnect the wires at a box. I just asked and she said she would much rather not.  It's not often she is at the cabin without me, but it does happen. I would want it to be a simple matter for anyone to unplug if they hear thunder rumbling around us.


Just because something has been done and has not failed, doesn't mean it is good design.


Dave Sparks

Quote from: MountainDon on July 28, 2014, 11:47:37 AM
The more I think about it the more I like the idea of having the ability to easily disconnect the feed from the PV panels to the CC, etc. I stress easy, as my wife is not going to want to get in there with a tools to reconnect the wires at a box. I just asked and she said she would much rather not.  It's not often she is at the cabin without me, but it does happen. I would want it to be a simple matter for anyone to unplug if they hear thunder rumbling around us.

I understand but most anyone offgrid ought to be able use a screw driver,  open the J-box, cut or disconnect the positive, negative, and ground separately and pull the conduit away from the house. The array should have disconnect to open the array. The problem with plugs/connectors is they often are a source of problems,  maintenance, and wear from not making a really tight connection over time. People will forget to open the breakers and then arc damage  the plugs. The J-box should be large and selected with the idea of easy disconnection.

Anyone who has phone, cable, or TV antenna/radio (solar) coming inside has the same issue. If you can disconnect it and move it away from something you are trying to protect, you will likely save it from most nearby strikes. prayer also helps

"we go where the power lines don't"

OlJarhead

Sorry for the troubles Don!  Yikes!

In this business (Telecom) lightening is an issue that we hope to avoid.  I've seen remote sites that have all kinds of grounds, surge protectors, lightening rods etc etc just flat out smoked.  Halo grounds inside the shelter blackened and the entire site toast because of a direct hit.

Training for cell technicians is simple:  if you see lightening LEAVE.  As in, if you see it even miles away, LEAVE.  It can travel over a mile on the ground and a big tower is, well, a big lightening rod.

Hope all the damage doesn't cost too much to replace/repair!  I can't begin to contemplate that!

JRR

The spiny steel "tree" that UK4X4 shows is about the ultimate in "air terminal" I would think.  Sharp metal blades that can quiver in a small breeze, would offer a lot of "bleeding" into the air stream.  This would help to neutralize any potential that might build between ground and clouds.  In the unlikely event of a strike .. the bolt should be greatly reduced in energy compared to what if would have been without the tree.  After all, light rods (forgive me, "air terminals") are intended to prevent strikes, not guide them.

Dave Sparks

Quote from: JRR on July 29, 2014, 03:13:30 PM
The spiny steel "tree" that UK4X4 shows is about the ultimate in "air terminal" I would think.  Sharp metal blades that can quiver in a small breeze, would offer a lot of "bleeding" into the air stream.  This would help to neutralize any potential that might build between ground and clouds.  In the unlikely event of a strike .. the bolt should be greatly reduced in energy compared to what if would have been without the tree.  After all, light rods (forgive me, "air terminals") are intended to prevent strikes, not guide them.

This is the goal to have the strike pick somewhere else. It does not hurt to give the air terminal a nice robust path to ground. On our sailboat the air terminal went to the stainless 5/16 inch mast rigging down to the chain plates. We would bolt on 3/8' anchor chain over the side about 2 feet in the sea. It always seemed to get nasty at night.....Nothing like lightning on the ocean. I do not miss that part!
"we go where the power lines don't"


MountainDon

Air terminals, assorted bases/mounts, clamps, clips and braided wire...



Next step will be the roof top for me.   I've already driven some ground rods in place. Once the air terminals are mounted I'll connect the wires and do some photos.

Just because something has been done and has not failed, doesn't mean it is good design.

rick91351

Don - you and Karen will have to move up there full time just to protect your copper investment.  I have not taken time to express how sorry I am that this occurred.  Yet you are pretty lucky no fire was started!!!   Don't know why you're doing all this when common knowledge is lightning never strikes twice.    ;)
Proverbs 24:3-5 Through wisdom is an house builded; an by understanding it is established.  4 And by knowledge shall the chambers be filled with all precious and pleasant riches.  5 A wise man is strong; yea, a man of knowledge increaseth strength.

JRR

Did your metal roof have any metal conductor-path to ground?  A cable dedicated to that purpose ... or metal gutters and metal down spouts?  I have always thought a metal roof to be a fair "air terminal"; your experience puzzles me...unless the roof metal was somewhat isolated from ground.  ??

MountainDon

I thought the metal panels made a good air terminal as well. There were two paths to earth from the metal roofing at diagonally opposite corners. Solid copper 6 gauge wire with S/S bolt through the panel, paint removed but the galvalume coating left intact and 8 foot copper clad steel ground rod driven 9 feet down.  One of the copper to roof panel connections shows carbon tracking around the S/S bolt. It was slightly loose; took a 1/2 tp 3/4 turn of the wrench.

The aluminum gutter on the south side was not tethered/connected to the metal roof. That might explain why the one gutter coupler blew apart. It was sealed with a sealant which shows traces of being scorched.

I suspect the earth was not making a high grade electrical ground connection; too dry. I'm in the process of adding extra ground rods, 8 feet apart as well burying several 12 to 20 foot lengths of scrap #2 copper wire in trenches, one end connected to the down wires and ground rods. Some of those are being run in the more moist waste water drain field. Others along the north side where there are no gutters and the ground is always more moist.

If this had happened before I did the concrete walkways a year or so ago I would have tied ground wires into the remesh used.



So far I have added a Midnite Solar Surge Suppressor to the AC service panel and replaced the blown apart Delta.

I have 2 more MN suppressors for the DC system; one to be placed at the PV array and the other at the upper end of the 300+ foot DC wire run. Close to the new MN Kid charge controller.  The upper end is also being changed to make it a simple matter to disconnect the DC power in lines (to the CC). The plan is to disconnect the DC from the CC input when there is the threat of lightning. Also in June through August, our main thunderstorm season, when we leave we will disconnect the lines.

Over the past few weeks with no loads on the batteries when we are absent, and no charging going on, I have found the batteries are healthy enough to have insignificant self discharge over a period of a week. Long term plans include adding a small PV panel and a cheapy CC to maintain a float charge. The MN CC will be isolated /disconnected and if lightning strikes again the cheapy CC will be sacrifical.




Just because something has been done and has not failed, doesn't mean it is good design.

JRR

I like the sound of the corrections you are making to the grounding system.  I think septic drain fields and tanks offer some good grounding opportunities ... as they are being constructed, of course.  Not so good for retrofits.


Dave Sparks

Quote from: JRR on August 13, 2014, 07:19:18 PM
I like the sound of the corrections you are making to the grounding system.  I think septic drain fields and tanks offer some good grounding opportunities ... as they are being constructed, of course.  Not so good for retrofits.

I use to know a very "skinny guy"  who could crawl into a ships black holding tank for repairs. He named his price and always got it.
"we go where the power lines don't"

MountainDon

#40
Just for the record, I am about done with the repairs and improvements. FWIW, in recap, here is what I have done.

Grounding improvements are in two separate sections; lightning rods or air terminals and grounding (earthing) the electrical system.

Air terminals. Four on the 16 x 30 cabin, 3 on the ridge and 1 on the S/S wood stove chimney. 26 strand 7/16" dia. wire used to connect all the air terminals. These extend down to the ground at diagonally opposite corners. Each wire first connects to an 8 ft. copper clad 5/8" dia. steel rod that is driven into a hole dug to make the bottom end of the 8 ft. rod 9 ft. below grade and set out from the cabin wall about 2 feet. The same wire is buried in a trench to run to a second rod about 10 feet distant on each side of the cabin. From that rod the wire extends another 10 feet or so to a 2 sq. ft. copper sheet buried about 2 - 2 1/2 feet down. All wires are covered with earth.  The terrain was reshaped slightly in places to permit the collection of rain water and snow melt to soak into the soil and make a better ground electrical connection.

The shed (8 x 8) has a TV antenna mast that reaches a height of 24 feet above roof level. This mast is down wire connected to a ground rod. A wire connects this ground rod to one of the ground rods at the cabin, a distance of something like 15 - 16 feet.

The barn (larger shed, 9 x 16) has two air terminal on the high side of the shed style roof. These are connected with the same 7/16" wire as used on the cabin. Here too the down wires drop at diagonally opposite corners. There are 2 ground rods at each corner, placed about 10 feet apart. One of these ground rods is connected to the ground rod at the TV mast. So all ground rods are inter-connected for best performance. Resistance between 1st and 3rd adjacent ground rods ranges from 2 to 6 ohms.  That may change over the span of the seasons. The ground is mosit right now. We'll have to resample later in the year and next spring and early summer. Several access points have been made to facilitate the re-measuring.


Electrical system grounding. This includes the ground rod system and the new surge suppressors or lightning arrestors.

I have Midnite Solar SPD's. One at the PV array combiner box. Another is 310 feet up the hill at a newly installed "power post" that is 10 feet from the cabin corner where the new Midnite Solar "The Kid" charge controller is located. A third MN SPD is located right at the CC input . A fourth is located at the DC wires that feed the inverter; this is a low voltage version as it is connected to the 24 VDC battery bank. Finally a fifth MN SPD is mounted at the AC service panel. At the PV array is also a Delta DC suppressor as well as a Delta AC version suppressor at the service panel. Nothing like redundancy. :)  And expense.  :(  A cool thing about the MN SPD is they have an LED that indicates that it is operational.


Grounding.  At the PV array I added four rods in a manner similar to the lightning air terminal system. That is rods connected to one another in a string with about 10 feet between rods. They extend to the pond area with the last rods directly parallel to the bermed low side of the pond. Probably the most moist area we have.  At the cabin all the hardware from CC to inverter, battery charger and service panel are individually connected to a ground buss. One end of the ground buss is connected by #2 copper wire to a ground rod at the new power post. From there a series of 5 ground rods extend into the grey waste water dispersal field. On the surface a series of bowls, centered around the rod positions, serve to catch, retain and permit soaking in of any precipiation.



Presently we are using a backup Samlex 1500 watt pure sine wave inverter for the cabin AC power needs. It does mean having to think when using the microwave or electric kettle. It will do until we decide if we really need the power capacity and convenience of something like the 3500 watt Outback that was toasted.


Lastly there does appear to be some hidden wiring damage in one of the lines to or between the gazebo, shed and/or barn. On occasion the GFCI that feeds that low use line trips. Sometimes it will not reset, sometimes it will reset several days later. The GFCI itself is good. It will be a tedious task to track down. Hopefully I'll track down the fault earlier rather than later. That's the Labor Day weekend project.




Just because something has been done and has not failed, doesn't mean it is good design.

MountainDon

I forgot to elaborate on a feature new to the PV system. Why did I install what I call the power post 10 feet from the cabin? It is to make it easy to physically disconnect the DC lines from the PV array to the charge controller. The suggestion came from Dave Sparks. Lightning can easily jump the small gap in a circuit breaker that is turned off. Now if the threat of lightning is imminent we can shut of the PV power feed with ease, disconnect the wires and pull them aside creating a large physical gap. During lightning season when we are absent we can leave the system disconnected. Just an additional preventative step. Most of the year, like fall through spring there is little lightning action likely so I feel safer leaving the system up and running then. Our absences in lightning season are short enough and no power is used from the batteries at all at those times that I feel there is little danger from battery self discharge.
Just because something has been done and has not failed, doesn't mean it is good design.

rick91351

Don to me that is a great idea and one  some might consider on or off grid. 
Proverbs 24:3-5 Through wisdom is an house builded; an by understanding it is established.  4 And by knowledge shall the chambers be filled with all precious and pleasant riches.  5 A wise man is strong; yea, a man of knowledge increaseth strength.

upa

Quote from: MountainDon on August 25, 2014, 08:59:07 PM


Presently we are using a backup Samlex 1500 watt pure sine wave inverter for the cabin AC power needs. It does mean having to think when using the microwave or electric kettle. It will do until we decide if we really need the power capacity and convenience of something like the 3500 watt Outback that was toasted.

Don, I am also sorry to hear about this unfortunate turn of events. Have you tried contacting Outback, as you likely already know most of the electronics in your toasted inverter are on three user replaceable boards, perhaps its not too expensive to fix. If the same happened to me I think I would have a hard time not replacing it with another outback or similar class inverter.

MountainDon

Thanks. Checking into that is just a matter of working through the to do list priorities.

There are many features the Outbacks possess that are very nice and not found in lesser equipment. I particularly like the Outback sleep mode "tunability" as well as the generator powered charger soft start up. (they don't kick in at full load like most other chargers, for those who have never had one.)

Just because something has been done and has not failed, doesn't mean it is good design.


MountainDon

I've determined that the damaged Yamaha EF2800i inverter generator would likely run again with a new electronic control box installed. At $700 I'm not sure I want to do that. It has just under 1000 hours on it, probably still good for another go round. I may just sell it cheap if anyone is interested. Not as quiet as the other Yamaha inverters or the Honda inverters, but not nearly as noisy as a 'big box" generator.

We are back in the PV power business now. I placed a Midnight Solar The Kid charge controller into service recently and am happy with it.  I'm running a Samlex 1.5 KW pure sine wave inverter while I ponder the fate of the Outback VFX3524M. It will probably get rebuilt and the Samlex placed back on the shelf as the emergency inverter. I really do like that unit. 

I even have some pictures I have to do something with and post 'em.
Just because something has been done and has not failed, doesn't mean it is good design.

NM_Shooter

Wow.  I am so glad you did not lose that cabin.

Sorry to not have read this thread more carefully.  Did you get the terminals and braid here locally?  I should put some on my cabin, as I am on a knoll with no trees around, and do not have a grounded roof. 
"Officium Vacuus Auctorita"

MountainDon

Hi Frank!  I checked locally and found only a couple of places that would sell & install. No parts sales only.  So I ordered online from a place in MA. Forget the name off hand.  I realize I have pictures and have not updated this thread. So we'll upload some pictures in next post.  I only have pictures of the completed project and only a few of those. I got carried away with the install and never took any inprogress pictures.

Just because something has been done and has not failed, doesn't mean it is good design.

MountainDon

The east gable end showing an air terminal and part of the down wire run.




18 inch air terminal, closer up




East end again. The air terminal is barely visible. The drop wire falls straight down into a hole with the ground rod driven down one foot below the surface. The down wire continues south in a trench to another ground rod approx. 15 feet from the cabin. Then it continues south for another 12 or so feet to a buried 2 ft sq copper ground plate. That is next to a wet area where the grey water terminates.

In the foreground is the new "power pole". The wires from the PV arrive underground and come up to a disconnect in the box. There is a Midnite Solar SPD (surge protection device, aka lightning arrestor) connected to the incoming wire there. On the other side of the post is a outlet for the DC line to the charge controller. It is a locking plug/socket. When in lightning season we can disconnect when we leave or if we are present we can disconnect when lightning threatens.




Close up of the plug end and the warning labels.




New SPD on the service panel





Ground down wire on the west end. As with the other end this connects to a ground rod driven one foot below surface. The wire then continues, unbroken, to another rod and a ground plate down the side of the cabin.




Just because something has been done and has not failed, doesn't mean it is good design.

MountainDon

Unfortunately one of the three pines that were struck has succumbed. The top greenery seemed okay till a couple months ago. Everything green was turning brown. So we took it down a few days ago.  The other two are as green as the surrounding trees that never got hot.  This one now shows that the pine bark beetles has something to do with the demise... lots of blue stain up to about half the 75 foot height. It never showed any signs; no sap globules so it never had any fight in it after the strike. Sure can take a while fpr a conifer to exhibit signs of sure death at times.
Just because something has been done and has not failed, doesn't mean it is good design.