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Jerm

join:2000-04-10
Richland, WA
kudos:2

AirFiber Ethernet Grounding

So I am mounting AirFiber on two 3-story buildings 1KM apart. We have a Cisco outdoor mesh, and previously all those installs were simply connected to an indoor ethernet surge/lightning protector (besides the radio chassis being grounded).

Protector on the Ciscos (pretty bad):
»www.ditekcorp.com/Docs/ProdGuide···heet.pdf

I had assumed since we haven't lost a single Cisco to lightning however in the past 5 years, using the same logic would be sufficient on the AirFiber. The cable entrance goes through an EMT conduit to the lan closet.

I had planned to ground the radio, plus use shielded outdoor CAT5e, and an indoor surge/lightning protector. Will that be enough?

On the AirFiber install guide it does show two outdoor lightning protectors on the CAT5, one right after the radio and one before it enters the building, and nothing inside. As I am not on a tower, and everything will be relatively "close" I was hoping to get by with just the indoor surge protector this time also.

Will this work with AirFiber's 50V PoE?
»www.protectiongroup.com/Surge/Da···-TSJ-GbE

Thanks for any help all!


WHT

join:2010-03-26
Rosston, TX
kudos:5

1 recommendation

I'd ask that in the UBNT airFiber forum where the guys that designed it are.

gunther_01
Premium
join:2004-03-29
Saybrook, IL
reply to Jerm
"standard" practice is one at the radio (to protect the radio from induced surges towards the radio), one at building entrance (to protect inside equipment), and I also add one inside for commercial accounts. Anything I can do to stop a strike from getting to all of their hardwired Ethernet computers I'd like to try and do.

NEC requires your suppression to be outside prior to entrance as well.
--
»www.wirelessdatanet.net


Jerm

join:2000-04-10
Richland, WA
kudos:2
said by gunther_01:

"standard" practice is one at the radio (to protect the radio from induced surges towards the radio), one at building entrance (to protect inside equipment), and I also add one inside for commercial accounts. Anything I can do to stop a strike from getting to all of their hardwired Ethernet computers I'd like to try and do.

NEC requires your suppression to be outside prior to entrance as well.

This is what I was trying to avoid. One at the radio, run 10', one at building entrance, run 10' more then one inside... all of a sudden I get a little worried about that PoE power making it through 3x protectors and the cost to do both cables going to the radio means I'm spending ~$1000 to ground a $1500 radio.

Perhaps doing just NEC is a better bet...

petecarlson

join:2004-11-06
Baltimore, MD
reply to Jerm
Here is what we use on every AF24 install:

At the radio:
»www.l-com.com/surge-protector-in···45-jacks

At a point near where the cables enter the building (indoors):
»www.l-com.com/surge-protector-di···rotector

I will admit that we normally install one at the radio, one at the rack, and just ground shield at entry.


Jerm

join:2000-04-10
Richland, WA
kudos:2
So I bought the models petecarlson recommended (and noted l-com was used on the ubnt forums) but I am only able to get 100mbps ethernet sync!

What a pain... bypassed in the indoor injector and still 100. No option to lock to 1000. Updated both ends from 1.0 to 1.5 no change.

I am going to bypass the outdoor injector just to see next...

Gah!


viperm
Carpe Diem
Premium
join:2002-07-09
Winchester, CA
Let us know what you did next if you get it working We have one to put up in the next couple weeks. What is the UBNT plugging into on the inside as far as a switch? are you sure it supports gigabit? and its not locked to 10/100? might be as 10/100 switch with gigabit uplink ports only I have seen people buy those thinking all ports are gigabit..

LLigetfa

join:2006-05-15
Fort Frances, ON
kudos:1
reply to Jerm
Not sure what you mean by "outdoor injector". If you mean surge protector, then ja, I have seen those degrade the ethernet to the point they don't negotiate speed properly. Bad cable or crimps can do the same.
--
Strange as it seems, no amount of learning can cure stupidity, and formal education positively fortifies it. -- Stephen Vizinczey


WHT

join:2010-03-26
Rosston, TX
kudos:5
reply to Jerm
said by Jerm:

had assumed since we haven't lost a single Cisco to lightning however in the past 5 years, using the same logic would be sufficient on the AirFiber.

Ohh...No.

Anyway...Bond the airFiber's steel mounting pole to the building steel with #2 or #4 ga copper and the airFiber's ground to the pole with $6. Use shielded cable bonded to ground at the top and bottom at the protector.


WHT

join:2010-03-26
Rosston, TX
kudos:5
reply to Jerm
The protectors are passive and won't load down your PoE voltage...until the conduct and fault to ground.


viperm
Carpe Diem
Premium
join:2002-07-09
Winchester, CA
reply to Jerm
Any updates if you corrected the problem and what the issue was...

petecarlson

join:2004-11-06
Baltimore, MD
reply to Jerm
We have lots of setups like that running gig. We did have an issue with some Cisco interfaces, but that didn't have anything to do with surge suppression.