Grounding of metal buildings

Grounding of metal buildings - E&S Grounding Ask the Experts

PJ Asked:
Inspector requires grounding of metal building, I plan to use a rebar in slab to tie to metal frame in another place?

Our Answer:
E&S recommend 10-ft ground rods, as this allows you to have 8-ft of the rod below the 1.5-ft mark, and still have 6-inches of the ground rod above grade for bonding purposes.  The National Electrical Code (NEC) now requires two (2) of these rods (unless you can measure the rod and prove it is below 25-ohms resistance-to-ground) be installed at least 6-ft apart.  You may want to install two (2) rods, one each at opposite corners of the building.  Bond the steel frame directly to the ground rods using a solid #6 copper wire (or larger).   And yes, ideally the rebar in the concrete should be bonded to the metal frame of the building.  We recommend at the 4 corners.  Please see the NEC 2011 Handbook for illustrations detailing the bonding requirements of rebar and the steel frames of buildings, as well as how to properly install a ground rod.

The Engineering Experts at E&S Grounding Solutions

nec, Grounding & Earthing Below-Grade Electrodes, rebar, inspectors, metal building

Related Posts

What Are Some Typical Electrical Grounding Testing Procedures? - E&S Grounding Ask the Experts

What Are Some Typical Electrical Grounding Testing Procedures?

Mike asked:What types of preventative maintenance electrical grounding testing procedures do you recommend for electrical grounding systems and how often?

Read More
How to calculate fault current in electrical substation grounding design? - E&S Grounding Ask the Experts

How to calculate fault current in electrical substation...

Milan asked:How do I calculate the fault current an electrical substation grounding design? I am trying to understand how to design a substation grounding system and fault current is something I am...

Read More
What is the mathematical formula for calculating the resistance-to-ground of parallel electrodes? - E&S Grounding Ask the Experts

What is the mathematical formula for calculating the...

Slamat Asked:What is the mathematical formula for calculating the resistance-to-ground of parallel electrodes?

Read More
What Is An Acceptable Earth Ground Resistance Value? - E&S Grounding Ask the Experts

What Is An Acceptable Earth Ground Resistance Value?

Mohammad asked:

Read More