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popcorrin
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Supplying power to equipment on tower installs?

Thu Dec 10, 2009 4:40 am

How do most people supply power to their equipment on tower installs. Let's say for instance you have 3 or 4 devices that you are mounting what would be the best way to get power to all of them.

Would you make cat 5 runs for each separate device and then connect them all via a switch at the base.

Would you run power up the tower to where the ap's are located and power them from there. If so, would you run ac and have regular electrical outlets or would you run dc up the tower and distribute it to your ap's somehow.

Would you utilize a poe switch and power all the devices from that(they seem to be quite expensive though).

Or would you keep your radios at the bottom and run lmr400 to your antennas? :)

I'm real curious to see how most people do it.
 
KillerOPS
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Re: Supplying power to equipment on tower installs?

Thu Dec 10, 2009 12:50 pm

shortest coax cable possible (1, max 2 meters), separate poe with ftp cable. No poe switch because that's a single point of failure in case of improper grounding and power-related mistakes.
That's the cheapest, most performant and reliable solution, because ftp cable is cheaper than low-loss coax, and POE power supplies are in most cases cheaper than POE switches. In some cases they come along with the radio (see UBNT series).
 
aaa
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Re: Supplying power to equipment on tower installs?

Fri Dec 11, 2009 1:09 am

On some country any AC installs not allowed on metal towers by safety reason.
 
popcorrin
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Re: Supplying power to equipment on tower installs?

Fri Dec 11, 2009 7:18 am

What about running low voltage, 12-24v, up the tower and then distributing it to your equipment from there? Would save on having to make multipe cat 5 runs?
 
KillerOPS
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Re: Supplying power to equipment on tower installs?

Fri Dec 11, 2009 1:56 pm

i would not do that, because you need more thick and expensive cable for that. And there is the added complexity of wiring all the equipment there. And what do you do if you need more than 100mbit up there? Use gigabit? A gigabit switch is more expensive than two or three cat5e ftp runs, that's for sure. And you need two of them.
Of course there are exceptions to the rule. For example when you don't have space near the tower, then you have no choice.
It's your choice. This is my opinion based on my experience.
You'll have to see which one is the cheapest option, without sacrificing essential performance. Most of the times it's cheaper to just oversize the whole thing at the beginning, rather than return and climb the tower again for yet another cable.
 
popcorrin
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Re: Supplying power to equipment on tower installs?

Fri Dec 11, 2009 4:24 pm

I don't think running dc voltage up the tower would take thick expensive cable since the wattage needed is fairly light. Basically poe is just running dc voltage up the tower on 24 gauge wire. Multiple strands of it mind you but it won't take very thick wire to equal the capacity of 10 pair of 24 gauge wire.

I actually won't need to run data up the tower since my bandwidth will be coming in on a wireless backhaul so the gigabit is not an issue.

When it's all said and done though I will probably do as you describe, and I really appreciate your input. I wanted to discuss it to figure out the pros and cons of each method.
 
KillerOPS
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Re: Supplying power to equipment on tower installs?

Fri Dec 11, 2009 7:06 pm

I actually won't need to run data up the tower since my bandwidth will be coming in on a wireless backhaul so the gigabit is not an issue.
Then pretty sure you don't need cat5e yet.
 
RK
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Re: Supplying power to equipment on tower installs?

Sat Dec 12, 2009 11:06 am

Depends on the height of the tower.
Generally, we like to run multiple cat5e cables and deal with the power and switching in the bottom.

It's cheaper to run a few more cables than having to climb the tower later.
 
popcorrin
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Re: Supplying power to equipment on tower installs?

Sat Dec 12, 2009 7:14 pm

Depends on the height of the tower.
How does this affect your decision? Does it have to do with the distance limit on poe runs? What do you do as an alternative?
 
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Re: Supplying power to equipment on tower installs?

Sat Dec 12, 2009 9:20 pm

Each situation is different. We have a 28' utility pole up on a hill, it has all the radios at the top with CAT5 running down to a utility box where all the neworking/POE are. If I was to do that one again, I would mount the antennas at the top and the radios at a more accessible height. It is a real bear to get to the top and if/when the equipment fails we are going to have *&^&%^% FUN. You have to think down the road, diagnosing, upgrading/replacing, repairing, etc--all these things WILL HAPPEN, and don't expect the weather to be beautiful when it happens! And also think about the fact that YOU might NOT be the one climbing, so it's not just a matter of what you would do but somebody else as well. I installed the gear on that pole, and I'll tell you, I won't climb that pole so-- how can I expect someone else to do it?
 
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Re: Supplying power to equipment on tower installs?

Fri Jan 08, 2010 3:30 am

In the past we have always had the luxury to have our equipment on existing buildings and or silos and could access the equipment Easley. Now we are fixing to install equipment on a 400-foot tower!! What are most people doing for this type of install?

The install is (2) RB433AH – (3) 120sectors and (1) backhaul

1. Install all routers on tower next to antennas and run cat5 down?
a. What about Ethernet limitation of 100 meters?
b. Place a Ethernet switch in the middle now you have to run power up to it also
2. Place antennas at top and routers at ground level?
a. This would make repair easy but you would have a lot of loss in the coax run
b. Place inline amplifiers at the top next to the antennas.


Any help would be grate
 
RK
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Re: Supplying power to equipment on tower installs?

Fri Jan 08, 2010 3:46 am

In the past we have always had the luxury to have our equipment on existing buildings and or silos and could access the equipment Easley. Now we are fixing to install equipment on a 400-foot tower!! What are most people doing for this type of install?

The install is (2) RB433AH – (3) 120sectors and (1) backhaul

1. Install all routers on tower next to antennas and run cat5 down?
a. What about Ethernet limitation of 100 meters?
Test your cable. See what kind of connection you get when using ~400' of it.
If the cable is good, it will very likely work.
 
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Re: Supplying power to equipment on tower installs?

Fri Jan 08, 2010 5:35 pm

Seperate cat-5 runs up the tower. I have seen 25 par cables on tower too. This makes one big bundle going up the tower. The only thing I don't like about those is the punchdown blocks you have to have. Makes for another point of failure.
 
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ne0031
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Re: Supplying power to equipment on tower installs?

Fri Jan 08, 2010 9:59 pm

As many others have said, it all depends on requirements, or more often - money.

We have customers who dictate 120VAC at the top, and we have those who only allow low voltage. We have fiber up towers, and cat5 (and 6). Sometimes a redundant 48v (or 24) supply with 10ga wire up the tower is the solution, and sometimes it isn't. There are added costs for more specialized surge protection when using large dc supplies.

Depending on your needs, running coax may be the best solution, or it may not. There are a large number of factors that will influence the decisions you make.

We even have customers who have us mount at 200' and run coax if needed farther up the tower, it's all relative.

What are your goals? Why are you mounting higher than 200' or so? Do you have to? Or are you subscribing to the 'higher is better' philosophy, which isn't always the case.
 
neoknet
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Re: Supplying power to equipment on tower installs?

Sat Jan 09, 2010 12:26 am

What are your goals? Why are you mounting higher than 200' or so? Do you have to? Or are you subscribing to the 'higher is better' philosophy, which isn't always the case.
Well yes I am using "higher is better" My thought is the higher I can get the AP the better luck i will have with the CPE

We have an avarage ground elv of 650' to 700' the tower is located a 930' and is a 400' tower. If I was to install a client CPE two miles away and they have 65'-70' trees I would think I would be more likeley to go over. To I have it ALL WRONG?

I would like to have the equipment up on the tower and bring down two Cat5E cables to the building plug each into there POe and then to a switch. This would keep coax loss down to a short run 5' to 10' of LMR600 as long as the ethernet would do the distance. YES it would be much easyer to replace routers,radios it it was on the gound. But the added cost in coax and amps for the case that we have a failure. if it takes 2 to 3 years before mother nature hits me I would be ok. If it happends offten the the money to move the equipment down the tower would be money well spent..
 
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Re: Supplying power to equipment on tower installs?

Sat Jan 09, 2010 6:58 am

Higher is better can work with proper downtilting. If your goal is to have the clients look up as much as possible it is a great way to go. I have seen towers at much higher elevations with forests around them. By placing the sectors at 270ish feet they were able to get clients in a 5-7 mile radius to have some sort of uptilt to deal with the trees.
 
JJOliver998
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Re: Supplying power to equipment on tower installs?

Sat Jan 09, 2010 2:06 pm

When I worked in Uganda, getting high quality Cat5e cable was a pain, and we had to deal with voltage drop of DC along the cable runs.

Obviously the higher quality Cat5 cable the better as in general it will have higher diameter cores and the voltage drop will be less. This is important because if you are running POE's and your using the RB433AH's, getting the correct power to them is very important as they seem less tolerant of voltage drop and draw large amount of current, this is amplified if you do have a voltage drop on the cable run!

I have put up some smaller towers (300ft), and I typically find that using a laptop power supply (48v 4a type) and wiring this to mains power cable (3mm twin and earth) and running this up the tower, keeping a distance from the data cable. Then at the top of the tower having a passive POE connected to the 3mm twin and earth cable, this keeps POE at about a foot (through a POE surge protector).

I've had massive problems attempting to use active POE inserters with RB433AH's.

Whilst this may not be the most ideal situation, it worked for me. I have no formal training and had to work in a very limited field setting to get wireless links up and running.

Josh.
 
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ne0031
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Re: Supplying power to equipment on tower installs?

Mon Jan 11, 2010 5:35 pm

What are your goals? Why are you mounting higher than 200' or so? Do you have to? Or are you subscribing to the 'higher is better' philosophy, which isn't always the case.
Well yes I am using "higher is better" My thought is the higher I can get the AP the better luck i will have with the CPE

We have an avarage ground elv of 650' to 700' the tower is located a 930' and is a 400' tower. If I was to install a client CPE two miles away and they have 65'-70' trees I would think I would be more likeley to go over. To I have it ALL WRONG?

I would like to have the equipment up on the tower and bring down two Cat5E cables to the building plug each into there POe and then to a switch. This would keep coax loss down to a short run 5' to 10' of LMR600 as long as the ethernet would do the distance. YES it would be much easyer to replace routers,radios it it was on the gound. But the added cost in coax and amps for the case that we have a failure. if it takes 2 to 3 years before mother nature hits me I would be ok. If it happends offten the the money to move the equipment down the tower would be money well spent..
"Go over" is the key. I assume this site coincides with your other posts...

If you have a single story home, and your client is installed at the peak of the roof, and the house is "in the trees" at more than a mile or so, then you may have issues regardless.

It's all about probability, and there are a lot of "if's" to deal with. PM me and I'll happily give you my opinions on your specific site/situation.

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