Metal frame of a building

[Jpflex]

A 2011 NEC grounding and bonding book I have allows the metal frame of a building to be recognized as a grounding electrode conductor according to 250.52A2 but is this still valid? I thought I seen in mike holts daily tip that this was not allowed?

If not what is the code to disallow this?

 

[letgomywago]

A 2011 NEC grounding and bonding book I have allows the metal frame of a building to be recognized as a grounding electrode conductor according to 250.52A2 but is this still valid? I thought I seen in mike holts daily tip that this was not allowed?

If not what is the code to disallow this?

It's OK for a GEC but not in lew of a EGC. Its also not just steel studs but more like pilings and heavy steel construction.

 

[Jpflex]

It's OK for a GEC but not in lew of a EGC. It’s also not just steel studs but more like pilings and heavy steel construction.

Do you have to measure GEC dimensions to ensure cross section area of steel pickings meet GEC requirements for type of electrode used?

 

[letgomywago]

Do you have to measure GEC dimensions to ensure cross section area of steel pickings meet GEC requirements for type of electrode used?

Not if it's steel in the footing bolted together to the rest of the building steel. It's like a ufer and is used for GEC for transformers and separate services in large buildings.

 

[Jpflex]

Not if it's steel in the footing bolted together to the rest of the building steel. It's like a ufer and is used for GEC for transformers and separate services in large buildings.

I forgot what an ufer was but I read it in the book I have once

 

[don_resqcapt19]

I forgot what an ufer was but I read it in the book I have once

it is what the code calls a "concrete encased electrode"