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Kitchen Remodel: Attic NM Run, Countertop Spacing, and Ungrounded Receptacles

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Kitchen Remodel: Attic NM Run, Countertop Spacing, and Ungrounded Receptacles

A 1978 single-family remodel. The kitchen has a 14 ft run of counter along one wall, interrupted at the midpoint by a sink, plus a 6 ft island with no plumbing. The owner wants four 20 A small-appliance circuits, a dedicated microwave circuit, and replacement of the existing receptacles, which sit in boxes fed by 2-wire NM cable with no equipment ground. The electrician proposes to feed the new circuits with 12/2 NM cable laid across the attic ceiling joists under 10 in. of blown-in insulation and passed diagonally through one bored hole in a doubled joist alongside two existing NM cables. The inspector flags the attic run and the island. The AHJ enforces the 2023 NEC with no local amendments.

1. Does the attic NM run comply? Show the ampacity and derating arithmetic and state what, if anything, must change.

Read the worked answer

Derating math. Type NM ampacity is taken from the 90 °C column for adjustment purposes, but 334.80 caps the final ampacity at the 60 °C column value.

  • 12 AWG Cu: 90 °C ampacity = 30 A; 60 °C ampacity = 20 A.
  • The bored hole carries the new cable plus two existing NM cables. With 12/2 cable, that is 3 cables x 2 current-carrying conductors = 6 CCCs. Table 310.15(C)(1) gives 80% for 4–6 CCCs.
  • 30 A x 0.80 = 24 A.
  • Final ampacity = lower of 24 A and the 20 A 60 °C limit = 20 A.

So the derated 12 AWG still carries the 20 A small-appliance circuit, and the bundling itself is not the violation.

What actually needs to change.

  1. The installer's method is fragile: the same routing with a 10/2 cable for a 30 A dryer-type circuit would fail (40 A x 0.80 = 32 A, capped at 30 A - it survives here by luck, but add one more cable at 70% and 40 x 0.70 = 28 A, which is a fail). Re-establish spacing or separate holes.
  2. Where the attic is accessible by a permanent stair or ladder, the protection rules referenced by 334.23 apply near the access point - staple to the side of joists or sleeve in a raceway rather than laying the cable exposed on top of joists near the hatch.
  3. Confirm termination temperature ratings. If any terminations are 60 °C-only, 12 AWG remains the minimum for 20 A, which it is here, so no change.

Verdict: electrically acceptable as built, but reroute for damage protection and document the derating calculation on the plan.

2. How many receptacle outlets are required on the 14 ft counter run, and what does the 6 ft island require?

Read the worked answer

Countertop run. 210.52(C) requires receptacle outlets so that no point along the wall line of the countertop is more than 24 in. from an outlet, and countertop spaces separated by a range, refrigerator, or sink are treated as separate spaces.

The sink splits the run into two 7 ft (84 in.) segments. Work each segment:

  • Outlets at 24 in. and 60 in. from the segment end give clearances of 24 in. / 36 in. / 24 in.
  • 36 in. between outlets is under the 48 in. maximum implied by the 24 in. rule.
  • Two per segment x 2 segments = four receptacle outlets minimum on the 14 ft run.

Both must be on the small-appliance branch circuits (210.52(C) outlets over the counter are served by the 20 A small-appliance circuits, at least two of which are required by 210.52(B)).

Island. This is the edition trap. The 2020 NEC added a requirement for at least one receptacle at an island or penultimate countertop; the 2023 NEC deleted that requirement. Under the adopted 2023 NEC, no receptacle is required on the island solely by 210.52(C). The inspector's citation is likely from the prior edition. Installing one is permitted and often good practice, but it is not a red-tag item - and if one is installed, it must be GFCI protected per 210.8(A) and AFCI protected per 210.12.

3. The existing counter receptacles are fed by 2-wire NM with no equipment ground. What are the compliant options, and what marking is required?

Read the worked answer

Under 406.4(D), a receptacle replacing one at an existing outlet with no equipment ground may be:

  1. A GFCI receptacle at the first outlet, with downstream receptacles fed from its load side and marked appropriately; or
  2. A GFCI circuit breaker protecting the circuit; or
  3. A grounding-type receptacle where an equipment grounding conductor is run back to a compliant point per 250.130(C) (any accessible point on the grounding electrode system, the service enclosure, or the panel's grounding bus).

Marking. Receptacles supplied through a GFCI on an ungrounded circuit must be marked "No Equipment Ground" (the supplied stickers). This is required at each receptacle outlet, not just the first.

Additional issues this job raises:

  • Kitchen branch circuits in a dwelling require AFCI protection (210.12); the usual answer is a dual-function (AFCI/GFCI) breaker, which satisfies both.
  • Do not bond the neutral to the receptacle yoke or create a bootleg ground from neutral to ground - that is a code violation and a shock hazard.
  • Because the house is pre-1980s, verify box fill (314.16) before adding a GFCI device and larger conductors; a GFCI receptacle body plus a 12 AWG splice can overfill a shallow 2-gang box.