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SESK: Stuff Everyone Should Know · sesk.info/elec-ground-rod-8ft

A ground rod electrode must be at least how long in contact with the earth?

At least 8 feet in contact with the earth.

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  1. 8 feet ✔
  2. 4 feet
  3. 12 feet

Why: Section 250.53 requires rod electrodes to have at least 8 feet in contact with the soil. Shorter rods do not make enough earth contact.

Huh, didn't know that: A single rod must get a supplemental electrode unless its earth contact resistance is 25 ohms or less.

The dad joke
Why did the short ground rod fail inspection? It just couldn't go the full 8 feet.
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References

Answer: 8 feet. Section 250.53 requires rod electrodes to have at least 8 feet in contact with the soil. Shorter rods do not make enough earth contact.

  1. EC&M: Code Q&A, Ground Rod Electrodes www.ecmweb.com/national-electrical-code/qa/article/20898150/code-qa-ground-rod-electrodes
    Ground rod electrodes must not be less than 8 ft in length in contact with the earth
    Checked 2026-10-10.

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