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Author Topic: Grounding a Gable mounted wireless anemometer.  (Read 3816 times)

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Offline Morbius

  • Posts: 6
  • Lisle, Il USA
Grounding a Gable mounted wireless anemometer.
« on: October 11, 2005, 10:18:13 PM »
I am mounting an anemometer on my house with a gable mount and a 5ft Antenna rod(metal).  The only wires lead to the power/transmiter unit. Radio Shack WMR-918/968 look alike.  Do I need to ground this?  If I do, what gauge and type of wire? Should it touch the roof? Picture would help.

Thanks in advance

Morbius

Offline administrator

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Re: Grounding a Gable mounted wireless anemometer.
« Reply #1 on: October 12, 2005, 11:16:27 AM »
It depends on what you're trying to protect against. If it's just to stop a buildup of static then almost any wire will do. Connect it to a good earth point (copper rod buried in the ground or maybe the water system if you've got metal pipework. Don't ground to metal gas pipes or to the earth pin of a mains plug.

If you're trying to protect against lightning, then you need a thick copper strap with a very good earth system in the ground. To be honest unless you're in a place very prone to lightning, this form of protection is probably more trouble than it's worth.
Chris
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Offline Morbius

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  • Lisle, Il USA
Re: Grounding a Gable mounted wireless anemometer.
« Reply #2 on: October 12, 2005, 01:39:24 PM »
Thanks for the information.  I have also looked up the NEC grounding reference and have a good 4 ft rod available to create the ground.  An additional problem is brought on by my 2 story configuration.  The wire would have to traverse the lower roof until I could direct it to the ground. 
I am trying to use the highest point in the 2 story house where the wind in not blocked.

I'll send a picture to better explain what I am trying to do.

Thanks for your help

Morbius

Offline niko

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Re: Grounding a Gable mounted wireless anemometer.
« Reply #3 on: October 12, 2005, 03:11:30 PM »
I may be wrong but I thought the NEC grounding requirement is intended for hard wired antennas where the feed line would be a conducting path to some point in the house and the ground connection serves to divert any strike to ground. I'm not sure you can apply it to a wireless device like this. Lightning's funny stuff, it's possible a nicely grounded 5 foot mast would be more attractive than if you left it ungrounded. If you are concerned you should seek expert advice, no information you get on here will be in any way authoritative or worth more than you are paying for it.
« Last Edit: October 12, 2005, 07:07:38 PM by nikoshepherd™ »

Offline Morbius

  • Posts: 6
  • Lisle, Il USA
Re: Grounding a Gable mounted wireless anemometer.
« Reply #4 on: October 12, 2005, 03:54:51 PM »
Your right.  I am concerned about grounding the mast. I have even thought about using a wooden rod.
Thanks for your advice
Morbius

Offline Richard_H

  • Posts: 66
  • Winterborne Whitechurch, Dorset, England.
Re: Grounding a Gable mounted wireless anemometer.
« Reply #5 on: October 12, 2005, 07:01:27 PM »
Hello All,

Niko is correct, if its wireless and doesn't have to be grounded, then on balance it's probably best not too (not sure about the rules and regulations covering electrical installations in your part of the world though).

Unless you go to really top notch professional lightning protection, which would cost lots of £'s or $'s, it is more trouble that it is worth, copper is very expensive !

If you are really worried, how about a fibreglass pole ?

Cheers,

Richard.....................
Science Graduate - "Why does it do that ?"
Engineering Graduate - "How does it do that ?"
Accountancy Graduate - "How much does it cost ?"
Media Studies Graduate - "You want fries with that ?"

Offline Morbius

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  • Lisle, Il USA
Re: Grounding a Gable mounted wireless anemometer.
« Reply #6 on: October 13, 2005, 04:39:58 AM »
Thanks for the advice.  I have used a thick wooden handle to get the anemometer working, while I research the grounding issue.  I had purchased a steel antenna support but held off.
I hope to provide good sampling of the weather here in Lisle, Il. I will finding a site for the other sensors later this week and have found this web site extremmely valuable both in the setup of this equipment and in the weather statistics available.  Thanks to all.

Morbius

Offline niko

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Re: Grounding a Gable mounted wireless anemometer.
« Reply #7 on: October 13, 2005, 09:25:09 PM »
You can usually purchase a fiberglass pole disguised as a fiberglass handled garden tool, rake, pole trimmer etc., cheaper than if you buy the same length of fiberglass pole  :)

Offline Morbius

  • Posts: 6
  • Lisle, Il USA
Re: Grounding a Gable mounted wireless anemometer.
« Reply #8 on: October 15, 2005, 05:31:20 PM »
Thank you all for the advice, I have now had the anaemometer up for some time and it is working well, the only problem is that the wooden rod that I used was a handle for somthing and has different widths up the rod.  I also have had in stor from previous projects a good solid straight wooden rod to use I think I will.  Any advice on this, telling me if an angl of about 5 degrees difference from 180? Please respond.

Thanks again!

 

cumulus