More NEC ambiguity metal frame of buildings

[Jpflex]

NEC code 250.52 (A) 2. Grounding electrodes. Says: if multiple metal in-ground support structures are present at a building or a structure, it shall be permissible to bond only one into the grounding electrode system
.

However

NEC 250.121 (B)

The structural metal frame of a building or structure shall NOT be used as an equipment grounding conductor

 

[roger]

Grounding Electrode Conductors and Equipment Grounding Conductors are different animals.

Notice the titles of Part III verses Part VI

 

[Jpflex]

Grounding Electrode Conductors and Equipment Grounding Conductors are different animals.

Notice the titles of Part III verses Part VI

Equipment grounding conductors also serves as bonding. If you bond to structural metal, it may become an equipment grounding when clearing equipment ground fault

 

[roger]

Equipment grounding conductors also serves as bonding. If you bond to structural metal, it may become an equipment grounding when clearing equipment ground fault

What it might do verses what it is intended to do is not the same thing.

Read through 250.4(A) & (B) for the reasons we do both

 

[don_resqcapt19]

NEC code 250.52 (A) 2. Grounding electrodes. Says: if multiple metal in-ground support structures are present at a building or a structure, it shall be permissible to bond only one into the grounding electrode system
.

However

NEC 250.121 (B)

The structural metal frame of a building or structure shall NOT be used as an equipment grounding conductor

However you also have to look to 240.104(C) for structural metal bonding requirements.