Weekly digest #92: inspector trends

What inspectors flagged most this week

Pulled notes from 40+ job sites across the network. Same patterns keep surfacing on rough and final. If you want to clear first-pass inspection, start here.

The top five callouts this week, in order of frequency:

1. Missing or mislabeled AFCI/GFCI protection on kitchen and laundry circuits (NEC 210.8, 210.12)
2. Tamper-resistant receptacle omissions in dwelling areas (NEC 406.12)
3. Working clearance violations at panelboards (NEC 110.26)
4. Bonding bushings missing on metal raceways entering service equipment (NEC 250.92)
5. Box fill calculations off by one conductor, typically on 4" square boxes with mixed #12 and #14 (NEC 314.16)

AFCI/GFCI: the 210.8(A) expansion still trips people

The 2023 NEC expansion of 210.8(A) to cover all 125V through 250V receptacles in dwelling kitchens, laundries, and basements is now the single biggest source of correction notices. Inspectors are specifically looking at ranges, dryers, and basement subpanels fed with 240V circuits.

If your jurisdiction adopted 2023 and you are still wiring like it is 2020, you will fail. Check the amendment page before you rough in. Some states adopted with modifications that carve out specific appliances, so the national code text is not always the final word.

Tip from a Michigan inspector this week: "I don't care what your supply house told you. Bring the label off the breaker to the inspection if the listing is unusual. Saves us both a trip."

Working clearance is the new favorite writeup

NEC 110.26(A) has been on the books forever, but inspectors are measuring it more aggressively this year. The 36" depth, 30" width (or panel width if wider), and 6'6" headroom are non-negotiable for equipment likely to require examination while energized.

Common failure modes we saw this week:

• Water heaters installed directly in front of subpanels in utility closets
• Shelving built out after rough by the GC, blocking the 30" width
• Panels installed with the bottom below 30" from the finished floor where a vanity or countertop later encroached
• Attic panels missing the dedicated equipment space per 110.26(E)

If the panel goes in early and trades follow you, walk the space before final. A quick tape measure saves a correction.

Grounding and bonding: small pieces, big rejections

Three bonding writeups came up repeatedly. Worth committing to memory if you do service work.

First, bonding bushings on concentric or eccentric knockouts at service equipment per 250.92(B). A listed bonding locknut or bushing with a jumper back to the neutral bar is the cleanest path. Second, intersystem bonding termination per 250.94. The little three-lug bar near the meter is not optional on new services. Third, supplementary grounding electrodes at detached structures fed by a feeder per 250.32, with a properly sized grounding electrode conductor.

The grounding electrode conductor itself keeps getting undersized on 200A services. Table 250.66 requires #4 copper for a 200A service to a ground rod, but only #6 to the rod if that is the sole connection. Know which rule applies to your installation.

Box fill and conductor count errors

Box fill math is tedious, and inspectors know it. They count. NEC 314.16(B) gives the allowances: each conductor passing through counts once, each device counts as two of the largest conductor connected to it, and all grounds together count as one of the largest ground present.

From a Texas journeyman: "If you are using 4x4 square boxes with a plaster ring as a habit, run the numbers on a three-way switch location with a #12 feed. You are probably full before you think you are."

Quick reference for common boxes and #12 THHN, following 314.16(A):

• 4" square, 1-1/2" deep: 9 conductors max
• 4" square, 2-1/8" deep: 13 conductors max
• 4-11/16" square, 2-1/8" deep: 18 conductors max
• Device ring deductions come off the box volume, so check the ring stamping for cubic inches

What to do before your next rough inspection

Five minutes of prep saves a callback. Before you call for inspection, walk the job with this in mind.

• Every 125V receptacle in a dwelling kitchen, bath, laundry, garage, basement, and outdoor location has GFCI upstream. Verify with a tester at the device, not just at the panel.
• Every 120V, 15A and 20A branch circuit supplying dwelling areas listed in 210.12(A) is on an AFCI. Confirm the breaker type matches the label.
• Box fill penciled out on the worst-case boxes, not the easy ones.
• Working clearance walked with a tape measure, not eyeballed.
• All bonding hardware installed, not just staged in the panel.

Inspectors are people doing a job. Make their pass fast and clean, and you build a reputation that pays back on every future permit you pull.