NEC 705.10 requires a permanent label or directory at every service equipment location listing all power sources and their disconnect locations. The label must carry the exact wording "CAUTION: MULTIPLE SOURCES OF POWER" and comply with NEC 110.21(B) durability standards. Missing or non-compliant 705.10 labels are among the most cited solar inspection deficiencies AHJs see nationwide.
Last Updated: April 19, 2026
You passed every Article 690 checkpoint — rapid shutdown label, system site map, string ID tags, the works. Then the inspector flags it: no power source directory at the main panel. Job fails.
NEC 705.10 is the solar labeling requirement that lives outside Article 690, and it catches crews off guard every time. It applies any time you add a power source — solar PV, battery storage, a generator — that interconnects with the utility grid. The label tells everyone from the AHJ to a responding firefighter that more than one source feeds this building.
This guide covers exactly what NEC 705.10 requires, where the label goes, what NEC 2026 changed, and how to make sure you never miss it again.
What Is the NEC 705.10 Power Source Directory?
NEC 705.10, "Identification of Power Sources," requires a permanent directory at the service equipment location for any building with multiple power sources. The requirement applies to all interconnected electric power production sources — solar PV, battery storage, generators, fuel cells, or any combination.
The directory must:
- List every power source connected to the building or structure
- Identify the location of each source's disconnecting means
- Include an emergency telephone number for any off-site company that services the system (added in NEC 2023)
- Be grouped with other placards or directories for other on-site sources
The 2023 NEC consolidated interconnected power source labeling under Article 705.10, pulling requirements that were previously scattered across multiple articles. The 2023 update also added the emergency contact requirement, aligning NEC with NFPA 1 (Fire Code), which first responders rely on at multi-source buildings. If your crew is still using a pre-2023 labeling template, check whether your 705.10 label includes that emergency contact field.
What Must the "Multiple Sources of Power" Placard Say?
The label must include this exact wording: CAUTION: MULTIPLE SOURCES OF POWER. Per NEC 705.10, this language is not optional — you cannot paraphrase it or substitute custom warning text.
Beyond the required caution wording, the directory must list:
- Each power source by type (utility service, PV system, battery storage, generator)
- The physical location of that source's disconnect (e.g., "Rooftop rapid shutdown at meter base," "Battery disconnect — utility room")
- An emergency contact number for any off-site monitoring or service company
The marking must comply with NEC Section 110.21(B). NEC 2026 updated Article 705 to reference 110.21(B) throughout — earlier editions pointed to Section 110.25, a style inconsistency the code-making panel corrected. The practical requirement is the same: labels must be legible, permanently attached, and durable enough for the environment where installed.
Code Callout: "Multiple Sources of Power" is required wording per NEC 705.10. AHJs enforcing NEC 2023 or 2026 will check for this exact text at service equipment. A custom label that says "WARNING: SOLAR SYSTEM PRESENT" does not satisfy Article 705.10.
Where Does the NEC 705.10 Directory Go on a Solar Installation?
The directory must be installed at the service equipment location or an approved readily visible location nearby. For a standard residential solar install, that means the main electrical panel or meter base — wherever the utility service terminates.
If a building has multiple service equipment locations (common in commercial facilities), a directory is required at each one.
Placement rules:
- At or near the main service panel — not at the inverter, not on the roof
- Readily visible — not hidden behind panel doors or mounted behind equipment
- Grouped with other on-site source directories when multiple sources are present
For a commercial solar-plus-storage system with a backup generator, all three sources belong on one directory at the service equipment location. One label covering all three disconnects satisfies NEC 705.10 for that location.
See Print Pro AZ's solar label placement guide for a complete diagram of where each NEC label goes on a residential install.
What Did NEC 2026 Change for Article 705.10?
NEC 2026 made primarily editorial changes to Article 705.10 — but those changes affect the marking standard your label must meet. The key update: all references to Section 110.25 have been removed from Article 705 and replaced with Section 110.21(B) throughout.
| Code Edition | Marking Standard Referenced |
|---|---|
| NEC 2020 | 110.25 |
| NEC 2023 | 110.21(B) (partial) |
| NEC 2026 | 110.21(B) throughout Article 705 |
NEC 110.21(B) requires that field-applied labels be "of sufficient durability to withstand the environment involved." For outdoor service equipment in Phoenix, Tucson, or anywhere in the Sun Belt, that standard demands UV-resistant materials. A paper label or standard office sticker won't survive a single Arizona summer — and an AHJ who knows 110.21(B) will flag it.
The substantive requirements of 705.10 — the exact wording, the directory contents, the emergency contact number — carried forward unchanged from NEC 2023. If you're already compliant with the 2023 version, NEC 2026 adds no new obligations. But verify that your label material meets the 110.21(B) durability standard, not just the older 110.25 reference.
How NEC 705.10 and NEC 690.56 Work Together on Solar Inspections
NEC 690.56 cross-references NEC 705.10 directly — which is why the power source directory ends up on solar inspection checklists even though it lives in a different article. Both sections apply at the same physical location: the service equipment.
Here's the distinction:
- NEC 690.56 label — identifies the PV system's rapid shutdown type and initiating device location for firefighters
- NEC 705.10 directory — identifies all power sources connected to the building and their disconnect locations for anyone working on or around the electrical system
Both labels are required. Both go at the service panel. Missing either one is an inspection deficiency.
Print Pro AZ's residential solar label bundle includes both the NEC 690.56 rapid shutdown placard and the NEC 705.10 "Multiple Sources of Power" directory label, pre-formatted to current code requirements and built to 110.21(B) durability specs.
Real-World Scenario: When NEC 705.10 Gets Missed
Here's a situation we see regularly at Print Pro AZ: a residential solar crew in the Phoenix metro completes a clean install — all the right Article 690 labels in place, properly positioned rapid shutdown system, site map laminated and mounted. Inspection day comes. One deficiency: no power source directory at the main panel per NEC 705.10.
The crew had used a solar-specific label kit that only covered Article 690 requirements. Article 705.10 wasn't on their checklist at all.
Re-inspection means a scheduling delay and a return trip. That's one label — it should never be the reason you fail.
The fix is simple: Add the 705.10 directory to your standard label pack and your pre-inspection walkthrough. Every grid-tied solar install requires it. No exceptions.
What Materials Pass Inspection Under NEC 110.21(B)?
NEC 110.21(B) requires field-applied labels to be durable enough to withstand the environment where they're installed. For outdoor or exposed service equipment, that rules out most paper and standard vinyl options.
Labels that fail in outdoor conditions:
- Paper labels — fade and detach under UV exposure
- Standard vinyl — adhesive fails in heat; ink fades in direct sun
- Inkjet-printed labels — water-soluble ink washes out in rain
Materials that meet 110.21(B) for outdoor installations:
- Aluminum — resists UV, heat, corrosion, and physical damage; the strongest option for harsh climates
- UV-stabilized polyester — flexible, aggressive adhesive, rated for outdoor use
- Polycarbonate with UV inhibitor — impact-resistant with long service life
For most residential installs in the Southwest, UV-stabilized polyester or aluminum is the correct specification. Print Pro AZ manufactures NEC-compliant solar label packs in Phoenix using outdoor-rated materials built for desert climate conditions.
Arizona AHJ Note: Phoenix-area AHJs have cited label durability failures on solar inspections — particularly for service equipment exposed to direct sun. Order materials rated for your climate, not the minimum spec.
Frequently Asked Questions
Does NEC 705.10 apply to every solar installation?
NEC 705.10 applies to any installation where a power source interconnects with the utility grid or other power sources. This includes virtually every grid-tied residential and commercial solar installation. Off-grid systems not connected to the utility are generally exempt, but always confirm with your local AHJ — jurisdiction-level requirements vary.
What is the exact required wording for the NEC 705.10 power source directory label?
NEC 705.10 requires the label to carry "CAUTION: MULTIPLE SOURCES OF POWER." This exact wording is required — paraphrasing is not code-compliant. The directory must also list each source's disconnect location and, per the 2023 NEC, include an emergency contact number for any off-site service entity.
Is one label enough if I have both solar and a battery storage system?
One directory listing both sources satisfies NEC 705.10, provided both sources and their disconnect locations are included. NEC 705.10 specifies that directories be "grouped with other plaques or directories for other on-site sources" — a single comprehensive label covering all sources is acceptable and preferred.
What is the difference between the NEC 705.10 label and the NEC 690.56 rapid shutdown label?
NEC 690.56 identifies the PV system's rapid shutdown type and initiating device for firefighters. NEC 705.10 identifies all power sources connected to the building and where to find their disconnects. Both labels go at the service panel, and both are required on every grid-tied solar install. They serve different purposes and are separate labels.
Get Your Labels Right the First Time
NEC 705.10 is a short code section with real inspection consequences. The power source directory is required on every grid-tied solar install, belongs at the main service panel, and carries exact wording that cannot be changed. NEC 2026 updated the marking standard reference from 110.25 to 110.21(B) throughout Article 705 — verify your label materials meet that durability standard for your climate.
Skip the re-inspection. Print Pro AZ ships NEC-compliant solar label packs — including the NEC 705.10 power source directory — direct from Phoenix to your job site.
Shop our NEC 2026 compliant solar label packs →
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Questions? Call Brent: (602) 649-5305
Brent Hanke | Print Pro AZ | (602) 649-5305 | b.hanke@printproaz.com Brent Hanke is the founder of Print Pro AZ, supplying NEC-compliant labels to contractors across the country.