BajaNomad - A Question About Lightening

A Question About Lightening

CaboRon - 8-3-2008 at 08:17 AM

This is a question about what to do in case of a lightening strorm ......

On the roof of my casa is a fifteen foot mast that holds the transmitter/receiver for my wi-fi dsl connection to Todso Santos.

Is this effectivly a lightening rod ?

Are there precautions to keep the lightenting from travelling down the LAN cable to my computer ?

Should I disconnect the LAN cable during storms ?

Would appreciate your considered opinions on this and any other actions you should take .... for instance should you unplug everything or should you shut power down at the service entrance ? Or at the street ?

Thanks,

CaboRon

losfrailes - 8-3-2008 at 08:21 AM

You should protect your equipment with lightning arrestors.

Here is a firm that sells them:

http://www.fab-corp.com/product.php?productid=1474&cat=2...

CaboRon - 8-3-2008 at 08:27 AM

Quote:

Originally posted by losfrailes
You should protect your equipment with lightning arrestors.

Here is a firm that sells them:

http://www.fab-corp.com/product.php?productid=1474&cat=2...

Appreciat the info, however I have a LAN cable comming from the mast .... not a tv connector.

CaboRon

k-rico - 8-3-2008 at 08:39 AM

Disconnecting the cables coming down from your roof mast if the storm is close by sounds like an effective preventive measure, but the stuff on the mast may still get fried.

Of course you won't be able to post on Bajanomad when you're disconnected.

You could instead go outside and fly a kite. :light:

http://en.wikipedia.org/wiki/Lightning_rod

TMW - 8-3-2008 at 08:40 AM

You should ground the mast to either a metal cold water pipe or drive a ground rod into the ground. You can also add a large ball of barb wire to the top of the mast to disipate the electric charge to minimize a lightning strike. The barb wire needs to be connected to ground thru the mast or a separate wire.

[Edited on 8-3-2008 by TW]

vandenberg - 8-3-2008 at 09:12 AM

Quote:

Originally posted by TW
You should ground the mast to either a metal cold water pipe or drive a ground rod into the ground. You can also add a large ball of barb wire to the top of the mast to disipate the electric charge to minimize a lightning strike. The barb wire needs to be connected to ground thru the mast or a separate wire.

[Edited on 8-3-2008 by TW]

Better make it razor wire. More fun to work with. :biggrin:

Cypress - 8-3-2008 at 09:55 AM

Had a lightening strike in the US. Everything electrical was inspected and installed according to code. Fried just about all the appliances, destroyed the well. Blew fuses right out of the fuse box. Repair guy said that if the fuse box had been closed it would probably have set the house on fire.

vacaenbaja - 8-3-2008 at 01:31 PM

As an old electronic teacher of mine once said "electrons are lazy, they want to find the easiest way home", in this case
ground.

BajaGringo - 8-3-2008 at 01:38 PM

TW gave you good information. I remember a few thousand dollars worth of gear getting fried by a contractor at a drilling camp in Sumatra during a storm back in the mid 90's. A technician received some second degree burns while sitting next to the equipment.

It was not a pretty sight.

Cypress - 8-3-2008 at 01:49 PM

What to do in a lightening storm? :?:

I'm not religious, but have said a prayer or two when the "Thunder Gods" were speaking.

stanburn - 8-3-2008 at 04:02 PM

Here in Santiago we have lightning 3 or 4 days a week during the summer. I disconnect the antenna feeds to the radios and disconnect all the electronic devices from the the power. I don't have a DSL antenna, but I would disconnect everything you don't wan't fried.

Stan

TMW - 8-4-2008 at 05:52 PM

Lightning strikes to communication towers are rare because of the lighning protection. I wasn't kidding about the barb wire and yes razor wire will work too. Any metal with a point on it will work. I think it was back in the 60s they started using barb wire wrapped around the top of the towers and around the lightning rods. The ideal was that the points will dissapate to ground the static charge in the air and reduce the flash over from lightning. Today modern tower builders have prefabed arrays to put on top. At our transmitter sight we have more problems with lightning hitting the power lines and causing equipment damage, even with transit protection. In 2005 we lost two transmitter tubes in two months. $30,000 each and warranty does not cover lightning. I finally installed a 3 phase delta to wye transformer to reduce line problems. We still get the trips sometimes but not the damage, so far. I'd say if you have a lightning storm coming thru do what stanburn does, disconnect everything.

CortezBlue - 8-4-2008 at 09:14 PM

Honestly there is not much you can do to guarantee not getting lightning into your house. So here are some suggestions:

1. Yes, by disconnecting all connections to the outside antennas will be the best thing you can do.

2. A dedicated ground wire from the cable . You should have received a connector that has a ground connection on the side that connects between the bottom of you wifi ant and your extension cable that leads to your computer or router. This is still no guarantee as a transient spark can jump the gound line and still enter your system.