250.64(B) Grounding Electrode Conductor Installation. Securing and Protection Against Physical Damage.

There is no minimum burial depth required for a grounding electrode conductor. Question: Is the conductor connecting the two ground rods (between the electrodes) required to be continuous, without a splice? Can the grounding electrode conductor be run from the service, through the intersystem bonding terminal and down to the first ground rod if it is continuous, without a splice?
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There is no minimum burial depth required for a grounding electrode conductor. Question: Is the conductor connecting the two ground rods (between the electrodes) required to be continuous, without a splice? Can the grounding electrode conductor be run from the service, through the intersystem bonding terminal and down to the first ground rod if it is continuous, without a splice?

Code Change Summary: Language was added to clarify that grounding electrode conductors and grounding electrode bond jumpers are not required to comply with 300.5.

NEC section 300.5 is all about underground installations and specifies the minimum cover distance required over the top of an underground wiring method. This section has never applied to a grounding electrode conductor or the bonding jumper between two grounding electrodes.

It is a good idea to bury an exposed grounding electrode conductor in order to keep it out of harm’s way, but there is nothing in the NEC® requiring a certain burial depth for the grounding electrode conductor.

Below is a preview of the NEC®.  See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).

2011 Code Language:

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.

2014 Code Language:

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. Grounding electrode conductors and grounding electrode bonding jumpers shall not be required to comply with 300.5.

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250.64(B) Grounding Electrode Conductor Installation. Securing and Protection Against Physical Damage.

Below is a Real Question from our Electrical Continuing Education Courses for Electrical License Renewal:

Which of the following is required for an exposed grounding electrode conductor?

A: It must be buried at least 12 in. below grade.
B: It must be buried at least 18 in. below grade.
C: It must be securely fastened to the surface on which it is carried.
D: An exposed 8 AWG grounding electrode conductor requires no physical protection.
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