NEC 408: Switchboards, Switchgear, and Panelboards
What This Article Covers
NEC Article 408 covers switchboards, switchgear, and panelboards — the equipment that distributes branch-circuit and feeder power. It specifies layout, working clearance integration with 110.26, and overcurrent protection rules.
Key Requirements
- Panelboards must be marked with their voltage and amperage rating
- Maximum of 42 overcurrent devices in a lighting and appliance branch-circuit panelboard (legacy rule — modern 408.34 simplified)
- Working clearance per 110.26 applies in front of panels
- Bonding and grounding per Article 250 — neutral and ground bonded only at service
- Series-rated combinations must be labeled and listed for that use
Common Field Applications
- Installing a 200A residential service panel
- Adding a sub-panel in a detached garage (four-wire feeder required)
- Checking working clearance for a panel in a closet
Common Mistakes & Inspection Failures
- Installing a panel in a clothes closet (prohibited — 240.24(D))
- Bonding neutral to ground in a sub-panel
- Insufficient working clearance
Related NEC Articles
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Frequently Asked Questions
What does NEC 408 cover?
NEC Article 408 covers switchboards, switchgear, and panelboards — the equipment that distributes branch-circuit and feeder power. It specifies layout, working clearance integration with 110.26, and overcurrent protection rules.
What are the key requirements of NEC 408?
Key requirements include: Panelboards must be marked with their voltage and amperage rating; Maximum of 42 overcurrent devices in a lighting and appliance branch-circuit panelboard (legacy rule — modern 408.34 simplified); Working clearance per 110.26 applies in front of panels. See the full requirements list on this page.
What are common mistakes with NEC 408?
Installing a panel in a clothes closet (prohibited — 240.24(D)) Bonding neutral to ground in a sub-panel Insufficient working clearance
Related Resources
Michael Briglio
IBEW Local 134 Journeyman · Licensed Contractor · IL Educator
Michael started in the IBEW at 18 and made foreman as a 3rd-year apprentice. Thirteen years in, he’s a Local 134 journeyman, a licensed electrical contractor, a licensed Illinois teacher, and OSHA 30 and EPA 608 certified. He teaches a federally recognized pre-apprenticeship on the south side of Chicago — where he’s helped 100+ students get into the IBEW. He built Sparky AI around exactly what the NJATC exam tests and what trips people up. Prep with this and you walk in ready.
Facts on this page trace to primary sources or first-hand IBEW Local 134 experience — see sources & methodology.