UL 1703 Solar Module Safety Listing: Replaced by UL 61730

Definition

UL 1703 was the safety listing standard for flat-plate PV modules in North America. Largely superseded by UL 61730 (aligned with IEC 61730) in 2020+. Modern modules carry UL 61730 listings.

Key Takeaways

UL 1703 = legacy PV module safety listing.
Superseded by UL 61730 (international alignment).
Existing modules with UL 1703 still permitted.
New modules use UL 61730.

UL 1703 vs. UL 61730

UL 1703 was the original North American safety listing for flat-plate crystalline PV modules, covering electrical safety, fire classification, and basic mechanical durability. Starting in 2020, UL began transitioning module certification to UL 61730, which harmonizes US requirements with the international IEC 61730 standard and adds more rigorous mechanical and environmental durability testing. The practical effect for a solar designer: modules purchased and installed today almost always carry a UL 61730 listing, while older systems already in the field may still show UL 1703 on their nameplate — both are recognized as valid listings for the equipment they were issued to.

Why the Listing Matters at Permit Time

An AHJ reviewing a solar permit package checks the module listing as part of confirming NEC 690.4(B) equipment-listing compliance. Getting this wrong — citing a discontinued UL 1703 listing for equipment that actually ships with UL 61730, or vice versa — is a common source of plan-check corrections that add days to a submittal. Keeping the equipment cut sheets and listing references in the solar permit design package current with what the manufacturer actually certifies to helps avoid that back-and-forth.

Equipment listings are one of several details an AHJ checks alongside the electrical single-line diagram and structural calculations during plan review, so getting the module and inverter certifications right up front saves review cycles — the Solar Permit Design FAQ walks through the equipment-documentation questions EPCs run into most often before submittal. For a look at how module safety certification fits alongside inverter-side requirements, Qbits Energy’s guide to solar inverter certification standards covers the equivalent listing landscape on the inverter side, and their IEC 61730 glossary entry is a useful companion for teams sourcing modules for projects outside North America.

Frequently Asked Questions

3 commonly searched questions about UL 1703.

Is UL 1703 still used?

Legacy modules still bear UL 1703 listings. New modules typically carry UL 61730 (aligned with international IEC 61730).

What replaced UL 1703?

UL 61730, aligned with the international IEC 61730 standard, replaced UL 1703 starting in 2020. Manufacturers now certify new module lines to UL 61730 rather than UL 1703.

Will an AHJ accept a module with only a UL 1703 listing on a new permit?

Existing systems with UL 1703-listed modules already installed generally remain compliant. For new permit submittals, most AHJs and equipment reviewers expect current UL 61730 listings, since that is what manufacturers are certifying new production runs to.