Clarification 250.68(C)(2)

[augie47]

250.68(C)(2) reads:
(2) The metal structural frame of a building shall be permitted to be used as a conductor to interconnect electrodes that are part of the grounding electrode system, or as a grounding electrode conductor.
Hold-down bolts securing the structural steel column that are connected to a concrete-encased electrode that complies with 250.52(A)(3) and is located in the support footing or foundation shall be permitted to connect the metal structural frame of a building or structure to the concrete encased grounding electrode. The hold-down bolts shall be connected to the concrete-encased electrode by welding, exothermic welding, the usual steel tie wires, or other approved means

For clarification: Can we look at this as two different statements. In other words, can I use the structural frame of the building as a grounding electrode conductor to interconnect electrodes (period)
OR
can I only use it to interconnect electrodes IF the provisions of the 2nd part are met (hold down bolts connected to UFER) ??

 

[wwhitney]

Definitely two separate allowances.

Cheers, Wayne

 

[augie47]

Follow up:
What advantage is gained by performing the "hold down bolt" part of this section if the steel frame is already considered a conductor.

 

[david]

250.68(C)(2) reads:
(2) The metal structural frame of a building shall be permitted to be used as a conductor to interconnect electrodes that are part of the grounding electrode system,

the above would be considered a bonding jumper. There is no reference to the building steel having to qualify as a grounding electrode to use the steel as a bonding jumper

or as a grounding electrode conductor.

That is an interesting statement, considering it just said it could be used as a bonding jumper

Hold-down bolts securing the structural steel column that are connected to a concrete-encased electrode that complies with 250.52(A)(3) and is located in the support footing or foundation shall be permitted to connect the metal structural frame of a building or structure to the concrete encased grounding electrode. The hold-down bolts shall be connected to the concrete-encased electrode by welding, exothermic welding, the usual steel tie wires, or other approved means

Since as you are aware your dealing with vertical footers

For clarification: Can we look at this as two different statements. In other words, can I use the structural frame of the building as a grounding electrode conductor to interconnect electrodes (period)
OR
can I only use it to interconnect electrodes IF the provisions of the 2nd part are met (hold down bolts connected to UFER) ??

The advantage I guess is you do not need a 4awg copper bonding jumper since the building steel would be your bonding jumper or your grounding electrode conductor

You still could however still use the #4 awg copper obtion

 

[david]

250.50 (3)(1) if multiple pieces are connected together by.........or other effective means to create a 20ft greater in length.

I guess another advantage when you consider the building steel as a bonding jumper one 10 foot concrete electrode under one column bolted with Jay bolts and another concrete encased electrode under a different column could be considered bonded together to create a 20 ft length