Ground Rings

[steve66]

Is there any value to installing a ground ring around a general office buiding?

Or would concrete encased electrodes at each corner of the building work just as well at a lower cost.

I am thinking of a general office building, about 300' long x 75' wide, (with maybe a bank inside) and maybe some tenants that rely heavily on computers.

What would be the minimum size for a ground ring to help reduce effects from lightning strikes? (I am assuming any installed lightning protection systems would have their own ground rods.)

Steve

 

[bphgravity]

A ground ring provides a method for connecting all the ground terminals of an LPS together in an effective manner. The buried conductor reduces the surge impedance as the voltage gradients are shared over the entire length of the ground ring.

 

[infinity]

A ground ring provides a method for connecting all the ground terminals of an LPS together in an effective manner. The buried conductor reduces the surge impedance as the voltage gradients are shared over the entire length of the ground ring.

Bryan,

Having said that do you think that a ground ring as outlined in the OP (about 800' of conductor) will really be useful?

 

[dereckbc]

For an office building would be a complete waste of money. Ground rings are use in places like Telephone offices, military communications centers, radio tower sites, data centers, etc. where outised plant cables and utilities entry at multiple points around the perimeter and need pretection devices installed where they enter the building.

 

[paul]

What would be the minimum size for a ground ring to help reduce effects from lightning strikes? (I am assuming any installed lightning protection systems would have their own ground rods.)

Steve

#2 AWG CU.

 

[Dean83169]

Wow some of these answers on this thing are like engineered answers. In plain electrician terms I do not see a need for a ground ring. The GEC is separate to the lightning protection. You need yours at least to the minimun based on your service. If its engineered with a ground ring then just do it but if your going to sell this based on what it may or may not do with the risk and liability of the equipment, I dont think the risk its needed or worth it on your end. IMO

 

[bphgravity]

My favorite quote regarding lightning:

1. Lightning is arbitrary, capricious, random, stochastic, and unpredictable.

2. The likelihood of lightning striking your facility or structure is remote. Perhaps one-in-a-million chance?

3. Your options are:

a. Do nothing. Run with the odds. Take your chances.
b. Do something. Get some information. Perform a safety and risk assessment. Install defenses for people and for the facility.

4. Lightning doesn't care what you do.