AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 702
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Has anyone ever have an observatory hit by lightning?
If so, what happened?
Also what measures has anyone taken to protect from lightning?
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39604
Loc: montana
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We get bad electrical storms here, but so far no hits. Interesting question!
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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Mike I. Jones
Carpal Tunnel
Reged: 07/02/06
Posts: 1536
Loc: Fort Worth TX
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The Supernova Search Telescope (SNST) at McDonald Observatory was hit by lightning years ago, and all the drive computers and motor control electronics were completely destroyed. Lightning rods extending above the building would have helped draw the leader stroke away from the building, but there were none installed. Surge protectors might have helped as well, but at the voltage and current transients present in lightning, it's impossible to know whether surge protection can be 100% effective. Better to draw the leader away from the building to begin with.
The Lightning Protection Institute at
http://www.lightning.org/
is an excellent resource for educating yourself on lightning protection and companies that sell equipment.
The National Lightning Safety Institute at
http://www.lightningsafety.com/
is also a great site for learning about lightning and protection from it.
Google on "lightning protection" and you will find several suppliers, such as
http://www.lightningrodparts.com/
and
http://www.harger.com/
As you can tell, I've looked into this myself. We live on a hillside NW of Fort Worth TX and get an uncomfortable number of lightning hits here (see attached photo from my back porch, taken with a wide angle lens, not a telephoto!)
I am going to put up lightning systems on both my house and observatory. I bought a Paramount and nice fast PC control computer for my various scopes to ride on, and am building my 16'x18' rolloff, so protecting my very costly electronics is "paramount" in my mind!
Mike
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56 mirrors, lenses, 16" f/6 Newt, 6" f/10 refractor, TOA-130S, Tinsley 5" f/15 Mak, 6" f/4 RFT, Coronado PST. Still to build: 24" f/10 Modified Dall-Kirkham, 10" f/26 Mak, 8" f/12 apo, spectrohelioscope, Herrig, Schupmann, and others.
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GJJim
scholastic sledgehammer
Reged: 09/09/06
Posts: 907
Loc: Western CO
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Nothing I know of will protect electronics from a direct lightning strike. For the power line surges caused by a strike nearby, consider powering the mount and associated gadgets from a UPS with a built-in isolation transformer. The isolated UPS essentially acts like a mini power station where all of the lines, including ground, are separated from the outside world. In my observatory I have a separate AC circuit from the UPS with outlets for the pier, the network router, and the PC.
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rodney
Vendor - Explora Dome
Reged: 03/08/05
Posts: 795
Loc: Asbury, NJ
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As Mike stated there are companies that make lightning dissipation rods. These look like giant pipe cleaners. I've seen them on sailboats for years as well as barns out in the country.
A gentlemen down in Maryland a few years back with a home dome 6 took a direct hit. It fried everything inside the observatory. He was running all Astro Physics equipment as well. I saw the OTA at a company in Maryland and it was destroyed. The kicker is the guy is a local weather forecaster. OUCH.
Something else to consider is the application of rebar used in concrete piers. It was told that lightning can effect your equipment even if it is a nearby ground strike. The strike could follow through the ground and make easy contact with the rebar thus causing a host of issues.
Just a couple thoughts.
Clear skies,
--------------------
My Explora Dome construction is here:
www.exploradome.us
Rodney
Meade 10 SCT
AT 8/F4 imaging scope
13 Truss
C8-NGT
Orion 80mm/F11
Canon 300D
Canon XSi
Two AS-GT mounts
Extremely happy Explora Dome home observatory owner
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AlienFirstClass
professor emeritus
Reged: 02/13/09
Posts: 702
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Quote:
The Supernova Search Telescope (SNST) at McDonald Observatory was hit by lightning years ago, and all the drive computers and motor control electronics were completely destroyed. Lightning rods extending above the building would have helped draw the leader stroke away from the building, but there were none installed. Surge protectors might have helped as well, but at the voltage and current transients present in lightning, it's impossible to know whether surge protection can be 100% effective. Better to draw the leader away from the building to begin with.
The Lightning Protection Institute at
http://www.lightning.org/
is an excellent resource for educating yourself on lightning protection and companies that sell equipment.
The National Lightning Safety Institute at
http://www.lightningsafety.com/
is also a great site for learning about lightning and protection from it.
Google on "lightning protection" and you will find several suppliers, such as
http://www.lightningrodparts.com/
and
http://www.harger.com/
As you can tell, I've looked into this myself. We live on a hillside NW of Fort Worth TX and get an uncomfortable number of lightning hits here (see attached photo from my back porch, taken with a wide angle lens, not a telephoto!)
I am going to put up lightning systems on both my house and observatory. I bought a Paramount and nice fast PC control computer for my various scopes to ride on, and am building my 16'x18' rolloff, so protecting my very costly electronics is "paramount" in my mind!
Mike
Good post...great picture.
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JAT Observatory
Got Cookies?
Reged: 02/20/05
Posts: 6762
Loc: Eastern PA
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Quote:
It was told that lightning can effect your equipment even if it is a nearby ground strike.
All my lightning issues have been a result of induction due to ground strikes.
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-Marcus
The problem with free speech is even the stupid have a voice.
http://www.jatobservatory.org
Currently a SV102A, WO 66mm & 10" LX200GPS OTA on a Paramount ME
(these OTAs subject to change without notice)
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lineman_16735
Tak-o-holic
Reged: 12/04/04
Posts: 2582
Loc: Central PA
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I have the same experience as Marcus. Marcus may even remember that a few years ago I had a nearby ground strike that fried everything in my observatory. Plugged in or not everything was smoked.
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Chris
A mount from Illinois
A scope from Japan
A camera from Cal-I-Fornia
A dog from Kentucky
A wife and kids from the "Twilight Zone"
The Geek Shed
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CarolG
scholastic sledgehammer
Reged: 10/16/06
Posts: 822
Loc: Oklahoma
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I have a question about lightning. My observatory has the wiring with wall plugs, but I use 2 extension cords to power those wall plugs. When I'm through observing for the night I unplug the extension cords and put them away. If lightning were to hit nearby or even directly onto the obs, would the equipment plugged into the unpowered wall plugs be vulnerable? It sounds like the equipment doesn't even have to be plugged in to be in danger. If that's so, how does one really protect their equipment?
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Carol
Cor Caroli Observatory
NS11 XLT w/ HyperStar
TV85 w/FeatherTouch/DM4/SC on a Scopebuggy
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lineman_16735
Tak-o-holic
Reged: 12/04/04
Posts: 2582
Loc: Central PA
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This is a pretty good article on electrostatic discharge Although this may not answer any of your questions. IMHO, you can not protect any sensitive electronics completely from lightning. It is good practice to unplug both ends of all your cables when a lightning storm is in the area. Also you should have a very detailed insurance policy. Also to clarify my previous post, nothing was connected to an AC source. My mount, and camera were connected to my laptop and my laptop was connected to my LAN. My guess was that the LAN connection did the dirty deed and fried my gear. The laptop was not powered on at the time.
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Chris
A mount from Illinois
A scope from Japan
A camera from Cal-I-Fornia
A dog from Kentucky
A wife and kids from the "Twilight Zone"
The Geek Shed
Edited by lineman_16735 (07/01/09 10:05 PM)
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David Pavlich
Postmaster
Reged: 05/18/05
Posts: 8512
Loc: Mandeville, LA USA 30.22 X 90....
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Quote:
Nothing I know of will protect electronics from a direct lightning strike. For the power line surges caused by a strike nearby, consider powering the mount and associated gadgets from a UPS with a built-in isolation transformer. The isolated UPS essentially acts like a mini power station where all of the lines, including ground, are separated from the outside world. In my observatory I have a separate AC circuit from the UPS with outlets for the pier, the network router, and the PC.
GET A UPS! It is the best protection you can get. Nothing will help if you get a direct hit as already stated. But a UPS is excellent insurance. I have one in my shop and have my computer/cash register and my stringing machine hooked to it as well as in my obs..
David
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Proud Member; PAS NOLA,
"If we knew what we were doing, it wouldn't be called research..."
A. Einstein
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Mike I. Jones
Carpal Tunnel
Reged: 07/02/06
Posts: 1536
Loc: Fort Worth TX
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Yes - agree on the UPS, and surge protector upstream from the UPS if it doesn't have one as part of its circuitry.
Also, make sure all electrical outlets and junction boxes are grounded right at the observatory. An 8' copper grounding rod should be pounded down into the ground right next to the building, and all the ground and neutral wiring should be connected directly to that local earth ground. Don't rely on a remote grounding rod to carry the discharge away - it won't all go over there.
Disconnecting from the line power or UPS is a good start, but when the main lightning discharge forks into several paths as it seeks ground, some of those paths could still pass through the air into equipment. I have witnessed secondary sparks over three feet long jump between farm equipment back in my more rural days on the old cotton farm!
Storing laptops, etc. in a well-grounded copper-screen enclosure (termed a Faraday cage) when not in use greatly improves their probability of survival after a lightning hit. The current conducts around the laptop to ground rather than passing through it.
It's not practical to store a Paramount or other tracking mount in a copper box, so it's still best to try to draw the leader away from the building altogether, to the extent possible anyway.
Mike
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LateViewer
scholastic sledgehammer
Reged: 11/17/05
Posts: 760
Loc: Westchester NY
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Quote:
An 8' copper grounding rod should be pounded down into the ground right next to the building, and all the ground and neutral wiring should be connected directly to that local earth ground.
If the circuit comes from an existing circuit breaker panel that already has a service disconnect then bonding grounds and nuetrals here may be a code violation. I don't have my book here now to double check but I think there is an issue.
As for driving a rod? Yes sir to that and a UPs. Also, you can bury a rod horizontally as well as drive it.
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12.5" Discovery String Truss Dob
DSV-1 Alt-Az Mount
WO 66mm Petzval
Orion 127mm Mak with WO 2" Dielectric Diagonal
Celestron CG-5 GoTo
8.8, 14, 18, and 24mm Meade UWA Series 5000 EP
32, 40mm Orion Optiluxe EP
Edited by LateViewer (07/02/09 08:56 PM)
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Odin
super member
Reged: 03/21/07
Posts: 191
Loc: Ont, Cdn 46N 84W
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Grounding can also be achieved with a ground Plate... buried min 24" below grade. Use #6 bare conductor.
Lightning strikes create Voltage Gradients, radiating from point of contact. Proper bonding & grounding are some of the best first steps for protection.
--------------------
*=== Life Is Great Under The STARS ===*
LX90 8" EMC
Rigel Quickfinder
ETX125PE UHTC
60mm Refractor Meade Digital Series
Meade Electronic Eyepiece
32mm,26mm,15mm,9.7mm series 4000 Super Plossl
2x Barlow
10x50 Tasca Binoculars
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Mike I. Jones
Carpal Tunnel
Reged: 07/02/06
Posts: 1536
Loc: Fort Worth TX
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Yeah, please check that if you can; I think I'm OK but it never hurts to check. I thought if I'm earth grounding on both ends it was OK to tie grounds and neutrals to the same bus bar. On the grounding rod, as much as I'd like to ditch it horizontally, the local code here says the ground rod has to be driven in vertically to get down to moisture for better conduction. Something else to check on. Not meeting code means not getting reimbursed by insurance companies!
Thanks,
Mike
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HunterofPhotons
sage
Reged: 04/26/08
Posts: 252
Loc: Rhode Island, USA
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Quote:
.....I thought if I'm earth grounding on both ends it was OK to tie grounds and neutrals to the same bus bar...... Not meeting code means not getting reimbursed by insurance companies!
Thanks,
Mike
It is not okay to have two earth grounds in this instance. There can easily be a difference in electrical potential between the two. Differing ground potentials can cause some flaky effects. It is indeed against code here in Northeast USA and probably in most of the country since most codes are 'standardized' now.
Your outlying observatory box should be such that the neutral and ground busses are separate. These are then combined back in the main box. Some subpanels have busses that are made to be separated, some do not. Just check before you buy.
dan
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GJJim
scholastic sledgehammer
Reged: 09/09/06
Posts: 907
Loc: Western CO
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Quote:
Also to clarify my previous post, nothing was connected to an AC source. My mount, and camera were connected to my laptop and my laptop was connected to my LAN. My guess was that the LAN connection did the dirty deed and fried my gear. The laptop was not powered on at the time.
Fiber optic ethernet links are available now at reasonable prices. Another option built in to most laptops and desktop PCs today is wireless 802.11.
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LateViewer
scholastic sledgehammer
Reged: 11/17/05
Posts: 760
Loc: Westchester NY
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I agree with Dan here.
What would need to be done is to remove the bonding screw from the neutral buss, or not install it if it was loose with the panel, and purchase a grounding bar to use in addition to the neutral buss.
Mike may have soil-ground-moisture issues out there in Texas. Generally here in the northeast we do not have those problems, though I do not know what they do on the barrier islands.
Unless otherwise prohibited by the local authority, burying a rod is the same as driving one. In many cases where the service is buried, the back filled trench serves this purpose well.
--------------------
12.5" Discovery String Truss Dob
DSV-1 Alt-Az Mount
WO 66mm Petzval
Orion 127mm Mak with WO 2" Dielectric Diagonal
Celestron CG-5 GoTo
8.8, 14, 18, and 24mm Meade UWA Series 5000 EP
32, 40mm Orion Optiluxe EP
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Mike I. Jones
Carpal Tunnel
Reged: 07/02/06
Posts: 1536
Loc: Fort Worth TX
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OK - so install a separate earth ground copper rod at the observatory but only attach all the grounds, boxes, etc. to it and leave the neutrals on a separate non-grounded bus bar in the observatory - right? The neutrals would be tied to the ground bus bar at the main breaker box but not at the observatory?
Mike
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Galaxyhunter
Pooh-Bah
Reged: 01/02/06
Posts: 1231
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Quote:
OK - so install a separate earth ground copper rod at the observatory but only attach all the grounds, boxes, etc. to it and leave the neutrals on a separate non-grounded bus bar in the observatory - right? The neutrals would be tied to the ground bus bar at the main breaker box but not at the observatory?
Mike, thats the way I have mine setup. I originally had my neutral bonded to the ground (like I have in my house), and the inspector told me I had to remove the bonding screw. I also used two grounding rods 8' apart.
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Carl
My lousy skies at Hawkeye Observatory
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