Cell tower structural work

[hhsting]

I have existing monopole tower for antenna which is grounded and bonded.

Now the structural engineer is going to place long shaft metal plate metallic on each side of the monopole tower by drilling holes in tower and bolted to outside of the tower frame so that tower structure is sturdy.

Does the new shaft metal plate need to be bonded to the tower? I looked at NEC 2014 section 250.4 but confused. It is likely to get energized since cables are going to antenna. Also would bolts count as being bonded or it needs wire?

 

[hhsting]

I have existing monopole tower for antenna which is grounded and bonded.

Now the structural engineer is going to place long shaft metal plate metallic on each side of the monopole tower by drilling holes in tower and bolted to outside of the tower frame so that tower structure is sturdy.

Does the new shaft metal plate need to be bonded to the tower? I looked at NEC 2014 section 250.4 but confused. It is likely to get energized since cables are going to antenna. Also would bolts count as being bonded or it needs wire?

The metal plates and install is like the following sites:

Tower Reinforcement Solutions - AF Tower

Tower Reinforcement Solutions AF Tower—via parent company Allfasteners—began producing fasteners for the tower industry more than twenty years ago whe...

www.aftower.com

 

[tom baker]

I would ask the tower company. Rules for towers and coax are in arts 810 and 820.
An exvellent resource for radio towers, equipment is Motorola R-56, google to find.

 

[hbiss]

I would think that because the plates are in intimate contact with the pole no additional bonding is required.

-Hal

 

[hhsting]

I would think that because the plates are in intimate contact with the pole no additional bonding is required.

-Hal

If you take a look at the picture below then the plate is not in contact with tower but bolt is. Please see side plate that’s in picture Not front plate to see better. Would you consider bolts as listed mean for bonding? I don’t see in NEC 2014

https://s-steel.com/files/sabre-2581211086_f2ec825cbc.jpg

 

[hhsting]

I would ask the tower company. Rules for towers and coax are in arts 810 and 820.
An exvellent resource for radio towers, equipment is Motorola R-56, google to find.

We don’t enforce Motorola R-56 only NEC. However I don’t see in NEC section 810 and 820 reinforcement cell tower plate bonding at all. Is it even in NEC2014? If bonding jumper is run from the plate then where would it go to tower structure or to tower ground bar if not then where?

 

[packersparky]

Is this even under the scope of the NEC? It would not be covered by the NEC here. Look at 90.2(B)(4)

(B) Not Covered. This Code does not cover the following:
(4) Installations of communications equipment under the exclusive control of communications utilities located outdoors or in building spaces used exclusively for such installations

 

[hhsting]

Is this even under the scope of the NEC? It would not be covered by the NEC here. Look at 90.2(B)(4)

(B) Not Covered. This Code does not cover the following:
(4) Installations of communications equipment under the exclusive control of communications utilities located outdoors or in building spaces used exclusively for such installations

This tower is owned by cell company like at&t it T-Mobile etc. Would that not be covered under NEC? Motorola R56 also points back to NEC many places. If it was not under NEC then why would it point?

 

[packersparky]

This tower is owned by cell company like at&t it T-Mobile etc. Would that not be covered under NEC? Motorola R56 also points back to NEC many places. If it was not under NEC then why would it point?

It seems to me that this is communications equipment under exclusive control of a communications utility and it would not be covered by the NEC. Just because another document references parts of the NEC does not mean that the NEC is adopted in its entirety for that particular application.

 

[hbiss]

Cell sites and towers are designed by engineers who know that kind of work and what they are doing. Why are you second guessing them and how are you even involved with it?

-Hal

 

[tom baker]

I was giving R-56 as a reference. If the tower is owned by AT&T the NEC does not apply. We have given you our opinions, make a decision and move on