Communications Tower???

[jahilliard]

I am an electrical contractor in SW Florida and I am bidding a project for a 150' Telco tower and I am not very familiar with these type projects and the bid is very short notice. I am looking for any heads up on what to expect and look for that may be debtrimental to labor and material and rental costs or anything for that matter. The area is fenced and will require grounding throughout with a generator and a few unoccupid buidings for misc equipment. Just received the drawings and have not been able to review in great detial. Mostly consists of underground conduits and pull strings and tons of grounding. Anyone with experience with these towers would be greatly appreciated for any info or questions etc.

 

[charlietuna]

Usually have a high spec on all materials and a serious grounding system--lightning protection with cadweld joints..

 

[Fulthrotl]

I am an electrical contractor in SW Florida and I am bidding a project for a 150' Telco tower and I am not very familiar with these type projects and the bid is very short notice. I am looking for any heads up on what to expect and look for that may be debtrimental to labor and material and rental costs or anything for that matter. The area is fenced and will require grounding throughout with a generator and a few unoccupid buidings for misc equipment. Just received the drawings and have not been able to review in great detial. Mostly consists of underground conduits and pull strings and tons of grounding. Anyone with experience with these towers would be greatly appreciated for any info or questions etc.

are there specifications to go with the drawings? usually, it's lots of cadweld,
ground grid, bonding and stuff. if you haven't bid this stuff much, one good
source of cadweld and grounding stuff is mayday grounding... you can google
them.

don't SWAG it. some of this stuff is breathtakingly expensive. i've had split
bolt lugs specified with threaded studs for attaching grounds. you hold one
in your hand, and think 3 or 4 bucks..... looks like a standard split bolt connector
with a 3/8" stud on the back.

nope. $19. can screw your day up if you need 200 of them.... and figured
them for $3 each.

 

[Rewire]

I worked on a few years back we laid the ground grid and had tails for all the spots that required them.When we came back in two weeks they had everything buried under six inches of chat.It was a pain locating all our tails especially for the fence.

 

[buzzbar]

re: Communications Tower???

I wired one of these years ago. The job I worked on required the use of #2 TINNED CU bare for the grounding around the tower. Cadweld joints throughout (we used the one shots).
The ground rods had to be 10' 3/4" copper clad. But this should all be in the specs.

Good luck, and I hope you like digging!

Andrew

 

[dezwitinc]

Most likely all terminations will require copper compression lugs.
As fulthrotl said, watch out for specialty parts, they can kill you on price and delivery. (This is the voice of experience).
ie:http://www.usmotors.com/products/ProFacts/burndyservitposts.htm

 

[Pierre C Belarge]

The focus of the thread so far has been on grounding...is there no other type of work with this project?

Do you have a Scope of Work?

Are you responsible for any of the raceways to be installed up the tower???? Pulling wire, mounting equipment, service work?

 

[LarryFine]

Hi, Andy, and welcome to the forum! :smile:

I did the ground work for a cell tower a few years ago. We used the tinned solid #2 copper. Everything bonds to the ground ring around the platform: platform legs, telco grounding block, power panel grounding, any nearby fence posts other metal, existing ring(s), tower legs, etc.

Same rods every 10 or so feet along the ring (which is 3' below grade) and anywhere else there is 10' of wire. Also, two test wells on the ring where the rods are shallower. Plus, we installed the supplied power panel and transfer switch, light w/photocell, and receptacle.

We ran four 2" PVC conduits from the power panel to the cabinet location on the platform, and two conduits to a nearby pole for power and phone lines. A GC did the excavating, fortunately. It was a tough but educational job, and an excuse for buying our rotary hammer.

We have some pix somewhere. Let me see if I can find them.

 

[ceb58]

What ever one is saying about the grounding is true. All of the tower I work with have ALL grounding connection cad welded then take to the ground bars located on the bulk head where the comm. cables come into the building. The gen. set is fairly straight forward, you may want to find out if the gen set will fall under legally requried system and if any thing in 708 will come into play. The inside of the build should have a halo ground around the inside of the building with every thing metal bonded to it and taken back to the ground bar on the bulk head also. There is more but with out knowing your scope of work its hard to say what to look for. One thing to be aware of is the final ohms reading from to grounding system. We require no more than 5 ohms. So if you do not have the equipment to test you may need to contract this to some one who dose this if this is in your scope

 

[LarryFine]

Okay, here's some:

Trench & rods / panel GEC's / phone grd / platform / meter / elbows / rod in well / light

 

[jahilliard]

larry this looks exactly like what there looking for. There are also "breathing Holes" which I'm not familiar with and I'm not familiar with "test wells" either. Can you describe what all was done, maybe howlong it took to complete the work, any other details. There are conduits and pull strings, did you guys have to install any cable or anything like that or was there mostly grounding, etc.?

 

[jmsbrush]

Ja, I have lots of experience with cell phone towers, Your test holes are where two pieces of #2 cu meet and hit a ground rod, Then a 6" pvc sleeve will cover that with a lid. The cadwell will be around 2' under the ground.
On the Telco side the only thing you will do is run PVC and use pull strings.
As far as the generators go, they were just using manual transfer switches and a gen plug. Now days most likely , the Generator will have an automatic transfer switch in it. You will run your power to and from that. It will also need Cat 5 wiring pulled for alarms going to a punch block inside the firebomb room.
Each carrier will get one, if they want to spend the money.

Everyone is talking about grounding because that is the most important. Cadwell, cadwel and cadwel. Anything thats metal needs to be cad. There's 3 metal plates on each side of the building, they all need to be cad. The fence. everything. Molds are expensive.

 

[dereckbc]

The focus of the thread so far has been on grounding...is there no other type of work with this project?

Do you have a Scope of Work?

Are you responsible for any of the raceways to be installed up the tower???? Pulling wire, mounting equipment, service work?

Pierre I design and spec a lot of this kind of work. 80 to 90% of the labor is grounding, as their is a lot of copper in the ground like ring around the shelter. tower, and fence line with radials.

The shelter comes delivered already built with all the electrical done at the factory. At least that is the way we do it. However the EC will run conduits for the service, telephone, and various alarm cables. If the site is equiped with a generator then the EC does that portion.

As for the tower, that is usually done by whoever errects the tower, and the EC will sometimes connect the control cable to the control box, but that is rare.

As for thermal weld or compression connector, that varies per Telco standard. Personally I always spec thermal weld followed by an inspection for all outside terminations below grade.