Does not change a thing, this says it all from 2011:
690.47 Grounding Electrode System.
(A) Alternating-Current Systems. If installing an ac system,
a grounding electrode system shall be provided in accordance
with 250.50 through 250.60. The grounding electrode
conductor shall be installed in accordance with 250.64.
(3) Combined Direct-Current Grounding Electrode Conductor
and Alternating-Current Equipment Grounding
Conductor. An unspliced, or irreversibly spliced, combined
grounding conductor shall be run from the marked dc grounding
electrode conductor connection point along with the ac
circuit conductors to the grounding busbar in the associated ac
equipment. This combined grounding conductor shall be the
larger of the sizes specified by 250.122 or 250.166 and shall
be installed in accordance with 250.64(E).
The only thing that changed was John Wiles got his wee-wee smacked for allowing separate GES to be used. Now it got corrected to state both AC and DC systems have to use a common GES. To much crap was getting blown up with separate GES, so it got corrected. The GEC to the panel frames and racking are still sized to 250.66. In 250.66 # 8 AWG Cu or #6AWG Alu. However most all installers use #6 AWG copper to take advantage of leniency allowed by:
250.64 (B) Securing and Protection Against Physical Damage.
Where exposed, a grounding electrode conductor or its enclosure
shall be securely fastened to the surface on which it
is carried. Grounding electrode conductors shall be permitted
to be installed on or through framing members. A 4
AWG or larger copper or aluminum grounding electrode
conductor shall be protected if exposed to physical damage.
A 6 AWG grounding electrode conductor that is free from
exposure to physical damage shall be permitted to be run
along the surface of the building construction without metal
covering or protection if it is securely fastened to the construction;
otherwise, it shall be protected in rigid metal
conduit (RMC), intermediate metal conduit (IMC), rigid
polyvinyl chloride conduit (PVC), reinforced thermosetting
resin conduit (RTRC), electrical metallic tubing (EMT), or
cable armor. Grounding electrode conductors smaller than 6
AWG shall be protected in RMC, IMC, PVC, RTRC, EMT,
or cable armor.
690.47 Grounding Electrode System.
(A) Alternating-Current Systems. If installing an ac system,
a grounding electrode system shall be provided in accordance
with 250.50 through 250.60. The grounding electrode
conductor shall be installed in accordance with 250.64.
(3) Combined Direct-Current Grounding Electrode Conductor
and Alternating-Current Equipment Grounding
Conductor. An unspliced, or irreversibly spliced, combined
grounding conductor shall be run from the marked dc grounding
electrode conductor connection point along with the ac
circuit conductors to the grounding busbar in the associated ac
equipment. This combined grounding conductor shall be the
larger of the sizes specified by 250.122 or 250.166 and shall
be installed in accordance with 250.64(E).
The only thing that changed was John Wiles got his wee-wee smacked for allowing separate GES to be used. Now it got corrected to state both AC and DC systems have to use a common GES. To much crap was getting blown up with separate GES, so it got corrected. The GEC to the panel frames and racking are still sized to 250.66. In 250.66 # 8 AWG Cu or #6AWG Alu. However most all installers use #6 AWG copper to take advantage of leniency allowed by:
250.64 (B) Securing and Protection Against Physical Damage.
Where exposed, a grounding electrode conductor or its enclosure
shall be securely fastened to the surface on which it
is carried. Grounding electrode conductors shall be permitted
to be installed on or through framing members. A 4
AWG or larger copper or aluminum grounding electrode
conductor shall be protected if exposed to physical damage.
A 6 AWG grounding electrode conductor that is free from
exposure to physical damage shall be permitted to be run
along the surface of the building construction without metal
covering or protection if it is securely fastened to the construction;
otherwise, it shall be protected in rigid metal
conduit (RMC), intermediate metal conduit (IMC), rigid
polyvinyl chloride conduit (PVC), reinforced thermosetting
resin conduit (RTRC), electrical metallic tubing (EMT), or
cable armor. Grounding electrode conductors smaller than 6
AWG shall be protected in RMC, IMC, PVC, RTRC, EMT,
or cable armor.
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