Solar PV Labeling Requirements: The NEC 690 Placard Package
Labeling is the last thing installed on a PV job and the first thing the inspector reads — and failed-label re-inspections cost a truck roll plus schedule slip. The code logic is simple once you see it: every label exists so that a firefighter or utility worker who has never seen the system can de-energize it correctly at 2 a.m. This guide inventories the placard set, the rapid shutdown rules, and the UV-rated materials that make it through 25 years on a roof.
1. The Placard Inventory: What Goes Where
Article numbers below follow the 2023 NEC; your AHJ may enforce an earlier cycle with shifted section numbers, so confirm the adopted edition before ordering placard sets. The content has been stable across recent cycles even where the numbering moved.
| NEC Ref | Label / Placard | Location | Inspector Notes |
|---|---|---|---|
| 690.56(C) | SOLAR PV SYSTEM EQUIPPED WITH RAPID SHUTDOWN | At the service equipment / system disconnect | Placard with array-boundary diagram; reflective white on red. The single most-checked label at final. |
| 690.13(B) | PV SYSTEM DISCONNECT (or equivalent) | Each PV system disconnecting means | Plus a warning that line and load terminals may be energized in the open position where applicable. |
| 690.53 | DC source ratings | At the DC disconnecting means | Maximum system voltage and maximum circuit current from the calculation, permanently affixed. |
| 690.54 | Interactive system point of interconnection | At the AC disconnecting means | Rated AC output current and nominal operating voltage of the interactive inverter output. |
| 705.12 area | Dual power source / backfed breaker warnings | Service panelboard & meter area | Identifies the second source and the backfed OCPD position; utility companies often add their own placard wording here. |
| 690.31 area | PHOTOVOLTAIC POWER SOURCE circuit marking | Exposed raceways, cable trays, junction/combiner boxes | Every 10 ft maximum, within 1 ft of turns and penetrations — reflective, white ≥ 3/8 in letters on red. |
2. The 10-Foot Rule: Reflective DC Circuit Marking
Exposed raceways, cable trays, and enclosures carrying PV system DC circuits get the red PHOTOVOLTAIC POWER SOURCE marking: reflective, capital letters at least 3/8 inch high, white on red, spaced at not more than 10 feet, plus within 1 foot of every turn, penetration, and connection point. It is the one label requirement on the job where ordinary outdoor vinyl is not good enough — "reflective" is a material property, not a color.
Brady B-921 Reflective Solar Labels are built on ASTM D 4956 Type 1 retroreflective sheeting with a clear acrylic overlaminate, rated -29°C to +82°C with up to 5 years average outdoor durability. Non-reflective placards elsewhere on the system can use B-920 overlaminated solar vinyl.
3. Material Selection for a 25-Year Rooftop
The catalog has four purpose-fit families for PV work — two for placards, two for equipment nameplates on inverters, combiners, and module frames:
The standard NEC placard set: rapid shutdown, disconnects, dual power source.
The 10-ft DC circuit markings where the code says reflective and means it.
Thermal-transfer printable equipment ID on inverters and combiner internals.
Serial/rating plates and barcode asset tags on modules and BOS hardware.
Why purpose-built stock matters: rooftop service temperature is not air temperature. Dark module frames and sheet-metal enclosures routinely hit 70–80°C under summer sun, then drop below freezing overnight — that daily expansion/contraction cycle is what shears cheap adhesives. The failure physics are covered in our outdoor UV durability guide.
4. Final Inspection Walkdown
- Rapid shutdown placard at the service equipment matches the actual shutdown type installed (array boundary vs. conductors-leaving-array) — mismatched diagrams are an instant correction notice.
- Every disconnect on the one-line has its identifying label, and open-position energization warnings appear where line and load can both be hot.
- DC conduit runs measure under 10 ft between PHOTOVOLTAIC POWER SOURCE markers, including the attic section the inspector will check with a flashlight.
- DC source placard values match the stamped calculation package, not the module datasheet defaults.
- All exterior labels are UV-rated stock with overlaminate or resin print — no office laser labels anywhere outdoors.
- Utility-required placards (dual power source wording, meter room directories) use the utility’s exact text; several utilities reject paraphrases.
Pricing out a placard package per site?
The Label Cost Calculator compares pre-printed placard sets against print-on-demand rolls across your annual install volume.