Minimum Size Grounding Conductor For Exposed Work

[Loffgren]

Some back ground. Working on two giant Boilers with conductivity probes that enter the process pipe through a "T" . My customer wants gounding conductors on the three part of the "T". My thought is to use ground clamps and run grounding conductors secured to existing conduits then drill tap an I-Beam (per there request). What is the minum size conductor for exposed grounds? I thought it was #6? But I can not locate the code section to prove it.

 

[qcroanoke]

some back ground. Working on two giant boilers with conductivity probes that enter the process pipe through a "t" . My customer wants gounding conductors on the three part of the "t". My thought is to use ground clamps and run grounding conductors secured to existing conduits then drill tap an i-beam (per there request). What is the minum size conductor for exposed grounds? I thought it was #6? But i can not locate the code section to prove it.

250.120 c

 

[Loffgren]

Thanks