Gounding mast

[27hillcrest]

Is it a code requirement to ground a mast on a roof top? Or just ground it for protection of the equipment. I have many to install. If the code requires, then what have some of you done for a ground on a 1-20 story building with rubber roof?

TIA

[charlie]

Yes, the mast must be grounded. However, the mast for the service drop is normally in front of the service disconnecting means so it is to be grounded to the service neutral. Assuming the mast is EMT, IMC, or RMC, and enters a meter fitting, the grounding is automatic since the meter fitting is grounded via the neutral connection that is bolted to the meter fitting. If you have a larger service that requires a rack for the service drop, the grounding is done with a jumper from the service drop to the metal rack. :)

[chris kennedy]

I thought OP was asking about something that would fall under Arts 800,810, something like that. If I ran a service mast up a 20 story bldg you would one tall pole to supply me with a service drop.:grin:

[Pierre C Belarge]

27
Are you asking about a piece of electrical equipment? or a flagpole type mast?

[27hillcrest]

The mast is for radio equipment for the police department. Sorry I was so vague. Some of the locations have no place to ground the mast at all. Would like to know if the code requires a ground for this type of installation.

[bphgravity]

Does the building happen to have a conventional lightning protection system?

See section 810.15 / 810.21 of the NEC...

[Sparky555]

The last antenna I installed included instructions for grounding.

Dave

[27hillcrest]

One of the 70 locations has a lighting protection installed on it. Can you attach an equipment ground to the lighting protection system by code? Most of the other locations have a rubber roof with nothing on it. On a few roofs there are antennas that are not grounded.

[iwire]

You really need to read Article 810 if your going to be installing antennas.

At the very least 810.15 and 810.21(F)

[Pierre C Belarge]

Possibly even contact the manufacturer of the mast...pass responsibility of installation on to others if you can...with the installation instructions.