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Rhaas
Premium Member
join:2005-12-19
Bernie, MO

2 recommendations

Rhaas

Premium Member

Towersite buildout part 2

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3/4
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Rest of cable rack is up
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MGB
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Cad welding 1/0 to MGB
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Finished bond
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1/0 to tower
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Nice new mold.. Bonding 1/0 to fence
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Turning the FNG loose to cad weld the fence posts
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Old thread wont let me add to it: »Towersite buildout

So I've had a bunch of stuff come up that has kept me from working at the tower site for the last month or so. But I've managed to slip away from the fiber projects long enough to get a little more done. Took the FNG out to teach him to cad weld as well.

John Galt6
Forward, March
Premium Member
join:2004-09-30
Happy Camp

John Galt6

Premium Member

Cadwelding...the most fun you can have without it being the Fourth of July.

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

1 edit

Rhaas

Premium Member

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Gah. JG pointed out my FNG ringed the sheath. This is how it should be done.. Now I get to teach the FNG how to use a cut off wheel..
keefe007
Premium Member
join:2004-02-24
Germantown, WI

keefe007 to Rhaas

Premium Member

to Rhaas
What's the difference?

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

When you ring a cable like that you will almost always nick the copper underneath and create a weak spot for the cable to break. The second picture (the one I did, I didn't pay attention to him stripping that cable) is cut on an angle.
lutful
... of ideas
Premium Member
join:2005-06-16
Ottawa, ON

lutful to John Galt6

Premium Member

to John Galt6
said by John Galt6:

Cadwelding...the most fun you can have without it being the Fourth of July.
Seems lots of cadwelding is being done for fun.

Most of the surge current will follow the tower legs and fence pole to ground. Safety/code bonding could have been done without cadwelding.

TomS_
Git-r-done
MVM
join:2002-07-19
London, UK

1 edit

TomS_ to Rhaas

MVM

to Rhaas
I have a combo question/suggestion, and a suggestion:

Q: do you buy your earth bars pre-drilled? If so have you considered making your own? We looked at buying them pre-drilled but it worked out several factors cheaper to buy a strip of copper bar, cut it and drill the holes ourselves. Saved an absolute fortune.

S: do you cover up/hide/disguise your copper earth wiring in any way? Specifically the stuff joined up to the fence or anything that is visible. We recently had someone break into one of our compounds and rip out all of our earth cabling. :-( I would recommend doing anything you can to obfuscate its existence.
lutful
... of ideas
Premium Member
join:2005-06-16
Ottawa, ON

lutful

Premium Member

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said by TomS_:

We recently had someone break into one of our compounds and rip out all of our earth cabling. :-( I would recommend doing anything you can to obfuscate its existence.
Outdoor copper disappear quickly in poor countries no matter how you hide them.

But some of these poor countries have frequent thunderstorms (see above chart for example) and telcos have limited budget for expensive equipment ... so their poor engineers were forced to develop robust grounding solutions which do not require copper or exothermic welding.

P.S. they use mainly steel which nobody still wants to steal.

John Galt6
Forward, March
Premium Member
join:2004-09-30
Happy Camp

1 recommendation

John Galt6 to lutful

Premium Member

to lutful
said by lutful:

Seems lots of cadwelding is being done for fun.

Most of the surge current will follow the tower legs and fence pole to ground. Safety/code bonding could have been done without cadwelding.
It is being done that way because that is the specification for almost all commercial sites.

A mid-class site will cost about $500K...the cost of the cadwelding is a very minor cost in terms of percentage, yet offers substantial benefits in terms of electrical efficiency, mechanical robustness, and longevity.
lutful
... of ideas
Premium Member
join:2005-06-16
Ottawa, ON

1 edit

lutful

Premium Member

said by John Galt6:

It is being done that way because that is the specification ... offers substantial benefits in terms of electrical efficiency, mechanical robustness, and longevity.
Alternative grounding methods which do not use shiny cadwelds and fat copper must be inefficient, flimsy, and transient ... only suitable for over-populated developing countries with frequent thunderstorms where poor telcos can't afford equipment loss or service downtime.

*** A relevant 2007 post with lots of debate ... I recall there were a few others on new tower grounding.
Bran New Tower, Grounding advise?

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas to TomS_

Premium Member

to TomS_
said by TomS_:

I have a combo question/suggestion, and a suggestion:

Q: do you buy your earth bars pre-drilled? If so have you considered making your own? We looked at buying them pre-drilled but it worked out several factors cheaper to buy a strip of copper bar, cut it and drill the holes ourselves. Saved an absolute fortune.

S: do you cover up/hide/disguise your copper earth wiring in any way? Specifically the stuff joined up to the fence or anything that is visible. We recently had someone break into one of our compounds and rip out all of our earth cabling. :-( I would recommend doing anything you can to obfuscate its existence.
1 - We do, only because we tend to get a good deal on them at times. Although I suspect that is ending. I will look into the bare bars.

2 - Yes - to an extent. Obviously a lot will be burried and good luck getting to it then. However visible stuff I generally paint with cold galv which will give the copper an appearance of being a steel cable from a distance.
Hahausuck
Premium Member
join:2003-12-14

Hahausuck to Rhaas

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to Rhaas
what are you using to bond the gate portion of the fence to the fence post there?

DaDawgs
Premium Member
join:2010-08-02
Deltaville, VA

DaDawgs to Rhaas

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to Rhaas
»www.ashireporter.org/art ··· ?id=1676

I posted this because I sense a ground war starting...

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas to Hahausuck

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to Hahausuck
said by Hahausuck:

what are you using to bond the gate portion of the fence to the fence post there?
»www.harger.com/products/ ··· infoid=0

TomS_
Git-r-done
MVM
join:2002-07-19
London, UK

1 edit

TomS_ to Rhaas

MVM

to Rhaas
said by Rhaas:

paint with cold galv which will give the copper an appearance of being a steel cable from a distance.
Yeah we did that with our most recent project.

Prior to that though it was just green/yellow coloured (Australian standard) cable running into some flex conduit before disappearig beneath the earth.

The last project we did actually used flat copper strap instead of cable. PITA to work with though, it comes as an unsupported spool/coil (the stuff we bought did anyway). Drop that thing and forget about trying to wind it back up all nice and neat...

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

I still have some 4" strap floating around, though what I have is in 10' lengths. Haven't really messed with it as I only have 1 mold for it.
wolfcreek
join:2003-12-02
Pagosa Springs, CO

wolfcreek to Rhaas

Member

to Rhaas
Dont want to start a grounding war but a couple of questions?

Why are you using such heavy wire to the fence posts. Why are you using insulated grounding wire? Are you grounding or bonding?

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

1 recommendation

Rhaas

Premium Member

Simple economics- we have/use a lot of 1/0 elsewhere and have decided to standardize our grounding/bonding with 1/0. Same goes with the reason it's insulated cable. Plus keeps us from having a bazillion molds to keep up with. I will leave the insulation on within about a foot of the building and tower (galvanic reasons) and the rest we'll strip bare.

This is bonding, actual ground ring has yet to go in though I am hoping to get the ring in within the week.
lutful
... of ideas
Premium Member
join:2005-06-16
Ottawa, ON

lutful

Premium Member

said by Rhaas:

This is bonding, actual ground ring has yet to go in
Hopefully that ground ring will eventually be bonded to properly engineered lightning surge protection scheme for all your equipment ...

... otherwise you will have to come back with another "lightning damage pics" thread and some expert will suggest what you needed was really "deep ground"
wolfcreek
join:2003-12-02
Pagosa Springs, CO

wolfcreek to Rhaas

Member

to Rhaas
I just wanted to make sure that people with smaller budgets were not discouraged thinking they needed that big of wire to bond items like a fence. While most specs call for #2 even #6 will work for bonding as there is actually no real impedence improvement of any resonable size of copper versus #6 at the frequencies that lightning occurs at. All one is trying to do with bonding is to prevent items from being at different voltages and not to divert surges.

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

said by wolfcreek:

I just wanted to make sure that people with smaller budgets were not discouraged thinking they needed that big of wire to bond items like a fence. While most specs call for #2 even #6 will work for bonding as there is actually no real impedence improvement of any resonable size of copper versus #6 at the frequencies that lightning occurs at. All one is trying to do with bonding is to prevent items from being at different voltages and not to divert surges.
Yep, I would use #2 tinned solid if we had it laying around like we do other sizes. Just so happens we end up with excess 1/0, 4/0 & #6 year after year from other projects/additions so I try to use as much of it as I can when I can. The majority of the internal bonding will be done with #6.

UHF
All static, all day, Forever
MVM
join:2002-05-24

UHF to Rhaas

MVM

to Rhaas
said by Rhaas:

said by TomS_:

However visible stuff I generally paint with cold galv which will give the copper an appearance of being a steel cable from a distance.
wait, what??

You paint COPPER with ZINC? I must be missing something here.
lutful
... of ideas
Premium Member
join:2005-06-16
Ottawa, ON

1 edit

lutful

Premium Member

said by UHF:

You paint COPPER with ZINC? I must be missing something here.
"Brawndo ... it's got electrolytes" as often mentioned in the cult movie Idiocracy.

compatible metal-metal connections:
»Corrosion at bulkhead joints

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas to UHF

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to UHF
said by UHF:

said by Rhaas:

said by TomS_:

However visible stuff I generally paint with cold galv which will give the copper an appearance of being a steel cable from a distance.
wait, what??

You paint COPPER with ZINC? I must be missing something here.
Well crap, I hate you all sometimes... I didn't even think about it..

Killa200
Premium Member
join:2005-12-02
TN

1 edit

Killa200 to DaDawgs

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to DaDawgs
said by DaDawgs:

»www.ashireporter.org/art ··· ?id=1676

I posted this because I sense a ground war starting...
Will never Ufer ground a site after talking to my boss about the radio pop on the ridge. They took a direct hit and when the lightning shunt to that ground in the foundation it blew that side of the foundation out of the building. Caused more damage than just letting the strike take the equipment, which it did anyways.

Up until that, i was all for it.

DaDawgs
Premium Member
join:2010-08-02
Deltaville, VA

DaDawgs

Premium Member

said by Killa200:

said by DaDawgs:

»www.ashireporter.org/art ··· ?id=1676

I posted this because I sense a ground war starting...
Will never Ufer ground a site after talking to my boss about the radio pop on the ridge. They took a direct hit and when the lightning shunt to that ground in the foundation it blew that side of the foundation out of the building. Caused more damage than just letting the strike take the equipment, which it did anyways.

Up until that, i was all for it.
Doesn't that show you that it actually works? The problem in your example was that the Ufer ground was located in the wrong part of the installation.
lutful
... of ideas
Premium Member
join:2005-06-16
Ottawa, ON

2 edits

lutful to Killa200

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to Killa200
said by Killa200:

Will never Ufer ground a site ... lightning ... blew that side of the foundation out of the building. Caused more damage than just letting the strike take the equipment
Maybe you and your boss have heard of Sandia Labs? They determined from many strike observations (with railway signalling equipment sheltes) that lightning strikes actually prefers to go through rebars/concrete into ground ... even when you deliberately insulate them.

From "zap_shelter" pdf file in another thread: "Surprisingly, the testing showed that typically less than five percent of the lightning current flowed in the lightning protection system ... ground impedance played only a trivial role ..." and then explains the dominant role played by building rebars and concrete.

*** this is an even better quote from zap_shelter: "The results of the tests were surprising, in that they suggested that the only function of the air terminals and lightning protection system was to conduct the current from the lightning flash to the rebar ..."