Grounding of an outdoor omni wifi antenna
Posted: Tue Oct 25, 2011 6:31 pm
Hi,
What I want to do : Mount an outdoor Omni-directional antenna on a house and connect it to a high power access point, which is inside the house, using a 40 feet LMR-400 Coaxial cable.
I'm about to install my first wifi antenna on a house for a customer. I'd like to do it right. At first I thought it was going to be easy. I saw some diagrams on manufacturer's websites. I saw some jobs done by amateurs online. It looked pretty easy. But then I stumbled upon a website with good information on the NEC (National Electrical Code in the USA) grounding requirements for installing antennas and coaxial cable : Satellite System Grounding (DBS Install) :
http://www.dbsinstall.com/diy/Grounding-1.asp
It made me think about covering my butt a little more, in case something would happen after the installation.
According to the NEC , the equipment should be grounded, so if something happens (like if a powerline falls on the equipment), it won't be a hazzard for humans life (cause a fire; electrocution) because it will be grounded. It's also a good way to discharge static electricity build ups. It makes sense. The NEC code requires the mast (or mount) of the antenna to be grounded. Plus they require that the coaxial cable is grounded. They require that the mast and the coaxial cable are grounded before the point of entry of the coax cable into the house (so if there's a surge, it won't go in the house, but be dissipated in the ground beforehand). (Note: I don't want to invest in sophisticated direct lightning strike protection.)
I've found some information on how to do this for satellite dishes.
Search for ground in this document (DirecTV dish install guide): http://www.directv.com/learn/pdf/SelfInstallGuide.pdf
My problem is, I don't find any indications that wifi installers are grounding their antenna mount anywhere... It seems that everyone are installing their equipment like they think. Or as the pretty looking diagrams they find on manufacturers websites.
Many company are selling some inline surge arrestors that you put in between two coaxial cables.
Look at "Simple Setup" Option 1 here: (AmpedWireless coax)
http://www.ampedwireless.com/products/apc25ex.html
In that example, the surge protector is inside the house...
My question is : Does the NEC code require, for wifi installations :
The grounding of the antenna mast?
The grounding of the coax cable, outside the house, before the point of entry (that is : put the surge protector outside the house and not inside)?
Do we have to ground to the main ground of the house absolutely? Or is it OK to just drive a metal rod in the ground, outdoor, close to the antenna?
Do you guys have any other suggestions for a first antenna install like this?
What I want to do : Mount an outdoor Omni-directional antenna on a house and connect it to a high power access point, which is inside the house, using a 40 feet LMR-400 Coaxial cable.
I'm about to install my first wifi antenna on a house for a customer. I'd like to do it right. At first I thought it was going to be easy. I saw some diagrams on manufacturer's websites. I saw some jobs done by amateurs online. It looked pretty easy. But then I stumbled upon a website with good information on the NEC (National Electrical Code in the USA) grounding requirements for installing antennas and coaxial cable : Satellite System Grounding (DBS Install) :
http://www.dbsinstall.com/diy/Grounding-1.asp
It made me think about covering my butt a little more, in case something would happen after the installation.
According to the NEC , the equipment should be grounded, so if something happens (like if a powerline falls on the equipment), it won't be a hazzard for humans life (cause a fire; electrocution) because it will be grounded. It's also a good way to discharge static electricity build ups. It makes sense. The NEC code requires the mast (or mount) of the antenna to be grounded. Plus they require that the coaxial cable is grounded. They require that the mast and the coaxial cable are grounded before the point of entry of the coax cable into the house (so if there's a surge, it won't go in the house, but be dissipated in the ground beforehand). (Note: I don't want to invest in sophisticated direct lightning strike protection.)
I've found some information on how to do this for satellite dishes.
Search for ground in this document (DirecTV dish install guide): http://www.directv.com/learn/pdf/SelfInstallGuide.pdf
My problem is, I don't find any indications that wifi installers are grounding their antenna mount anywhere... It seems that everyone are installing their equipment like they think. Or as the pretty looking diagrams they find on manufacturers websites.
Many company are selling some inline surge arrestors that you put in between two coaxial cables.
Look at "Simple Setup" Option 1 here: (AmpedWireless coax)
http://www.ampedwireless.com/products/apc25ex.html
In that example, the surge protector is inside the house...
My question is : Does the NEC code require, for wifi installations :
The grounding of the antenna mast?
The grounding of the coax cable, outside the house, before the point of entry (that is : put the surge protector outside the house and not inside)?
Do we have to ground to the main ground of the house absolutely? Or is it OK to just drive a metal rod in the ground, outdoor, close to the antenna?
Do you guys have any other suggestions for a first antenna install like this?