NEC 409 Nameplates: Where the Code Ends and the Listing Begins
NEC Article 409 is short, and its marking section — 409.110 — reads like a nameplate spec because it is one. The confusion on real jobs is never the list itself; it is who owns each line: the panel shop, or the installing electrician. This guide splits the marking package by responsibility, so the panel arrives with its half done and the field crew knows exactly what remains.
1. The Marking Package, Split by Who Owns It
The middle column is the one that settles arguments at final inspection:
| Required Marking | Who Provides It | Field Notes |
|---|---|---|
| Manufacturer identification | Panel builder (factory nameplate) | Name or trademark of the responsible organization |
| Supply voltage, phases, frequency, FLA | Panel builder | One set per incoming supply circuit |
| Short-circuit current rating (SCCR) | Panel builder (UL 508A SB4 calc or tested) | The number plan reviewers check against available fault current |
| Fed-from-multiple-sources marking | Installer (field condition) | Required where more than one disconnect de-energizes the panel |
| “Suitable for use as service equipment” | Panel builder, only where applicable | Only when the panel is actually applied as service equipment |
| Arc flash warning (NEC 110.16) | Installer / owner | Generic field warning; detailed 70E label follows the site study |
| Electrical diagram number | Panel builder | Ties the enclosure to its documentation set |
2. SCCR Is a Marking Problem Twice
First at the factory: the panel builder computes the assembly SCCR (weakest-component method per UL 508A Supplement SB4) and prints it on the nameplate. Then in the field: the plan reviewer compares that number against the available fault current at the installation point. A 5 kA default SCCR on a feeder with 35 kA available is a rejected installation — and no label material fixes an arithmetic problem. What labels do fix:
- A nameplate that is still legible at the 10-year service call — UL 969 recognized polyester, resin-printed, not a laser label under packing tape.
- A nameplate that is still attached — on textured powder coat that means B-483 rubber-based adhesive or B-593 foam-backed plates, per the powder coat adhesion guide.
- Revision honesty — when a drive swap changes the SCCR, the nameplate gets reprinted, not annotated with a paint pen.
3. How 409 Sits Among Its Neighbors
Building the full label schedule for a panel?
The Panel BOM Builder generates nameplates, warning decals, and wire marker quantities from your panel schedule in one pass.