Quick Hits

PART III — GROUNDING ELECTRODE SYSTEM & GROUNDING ELECTRODE CONDUCTOR

EPISODE 12 — The Grounding Electrode System & What Counts as an Electrode (270.50, 270.52)

Slide 1 — Hook "New Part! Today: what actually counts as a grounding electrode, and the rule that ties them all together."

Slide 2 — 270.50 The system concept

• Every qualifying grounding electrode present at a building/structure has to be bonded together to form ONE grounding electrode system.

• If none of the "naturally occurring" electrode types exist, you have to install one of the other permitted types.

Slide 3 — 270.52 The electrode types (permitted)

• Metal underground water pipe (10+ ft in earth contact, electrically continuous)

• Metal in-ground support structures (10+ ft vertical earth contact — pilings, casings, etc.)

• Concrete-encased electrode ("Ufer ground") — 20+ ft of rebar (½"+ diameter) or bare 4 AWG+ copper, encased in 2"+ of concrete

• Ground ring — 20+ ft of bare 2 AWG+ copper encircling the building

• Rod/pipe electrodes — 8+ ft long, specific material/diameter rules

• Other listed electrodes

• Plate electrodes — 2+ sq ft of soil exposure, specific thickness rules

• Other local metal underground systems (piping, tanks, well casings not bonded to a water pipe)

• NOT permitted: metal gas piping, aluminum, or certain pool-related structural rebar.

Slide 4 — Quiz + CTA Q: "A concrete-encased electrode ('Ufer ground') using rebar must be at least how long?" A) 10 ft B) 20 ft C) 30 ft D) 6 ft

✅ Answer: B — 270.52(A)(3): at least 20 ft (6.0 m).

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