Solar Cable Standards: EN 50618, IEC 62930 and UL 4703 Explained

Solar cable standards define product requirements, but project acceptance also depends on installation rules and the certification scope of the supplied cable. Buyers need to match the specified standard, electrical ratings and supporting documents to the actual installation.

EN 50618, IEC 62930 and UL 4703 appear frequently in PV cable specifications. They are separate standards with different scopes; a reference to one does not establish compliance with the others. We recommend checking the required evidence before approving a cable substitution or purchase order.

EN 50618, IEC 62930 and UL 4703 are principal product standards used for photovoltaic cables and wire. Their relevance depends on the destination market and project specification. USE-2 is a cable type associated with UL 854, rather than another name for UL 4703 PV Wire. [Sources: BSI, IEC and UL Solutions.]

Product standards describe the cable, installation rules govern its use, and certification schemes define how conformity is assessed. These three layers answer different procurement questions.

A test report should identify the samples and tests covered. A product certificate or listing should identify the certified product scope. Buyers should check which document the contract requires before treating either as sufficient evidence.

For solar cable standards, this distinction prevents a common purchasing error: accepting a document that mentions the right standard but does not cover the cable being ordered.

The destination market determines the applicable installation framework, while the project specification may add requirements beyond basic product conformity. UL Solutions identifies differing global requirements as a reason to evaluate PV cables against the standards relevant to each market. [Source: UL Solutions.]

For example, an EPC contractor purchasing cable for a 1,500 V DC array should check the declared voltage rating, certification scope and proposed route together. A cable acceptable beneath modules may require further review where it enters a building, crosses an accessible area or runs underground.

Before comparing quotations, record:

• Destination and code edition: country, jurisdiction and applicable installation rules.
• Electrical requirements: maximum circuit voltage and required conductor size.
• Installation conditions: exposed routing, conduit, burial or building entry.
• Additional exposure: standing water, chemicals or repeated movement.
• Required evidence: named certification scheme, test reports and project approval documents.

Solar cable standards should be stated explicitly in the RFQ. A request for “international-standard solar cable” leaves suppliers free to quote different compliance packages.

EN 50618 and IEC 62930 both address photovoltaic cables, but their scopes are not identical and compliance is not automatically interchangeable. IEC 62930 covers single-core cables with cross-linked insulation and a cross-linked sheath for PV DC circuits up to 1.5 kV between conductors and between conductor and earth. [Source: IEC 62930:2017.]

EN 50618 specifies flexible, halogen-free PV cables, while IEC 62930 includes a broader range of conductor constructions and material categories. In particular, IEC 62930 includes both halogen-free low-smoke cables and cables that may contain halogens. [Sources: UL Solutions and IEC.]

*The size ranges describe standard coverage, not the scope of every manufacturer’s certificate. [Sources: UL Solutions; Nexans product documentation for the H1Z2Z2-K designation.]

An IEC 62930 claim alone does not establish that a cable is halogen-free. If a project requires low-smoke, halogen-free construction, specify that requirement separately and verify the offered cable category and supporting evidence.

When comparing these solar cable standards, use the actual product documents. Two cables with the same nominal cross-section and similar outer appearance may have different certified constructions.

A dual-compliance claim requires evidence for both named standards and the exact product offered. A datasheet stating “EN 50618 / IEC 62930” is a starting point for review, rather than a substitute for supporting documents.

BSI lists BS EN 50618:2014, and IEC lists IEC 62930:2017. Buyers should check the applicable edition, amendments and certification transition requirements when placing the order. The publication year alone does not determine whether a certificate remains acceptable. [Sources: BSI and IEC.]

For dual claims, check:

• Standard references: both standards appear in the relevant conformity documents.
• Product identity: model and construction correspond across the documents.
• Scope: the ordered size and voltage are included under both claims.
• Document status: certificates remain valid under the issuing scheme.
• Traceability: cable markings and delivery records identify the covered product.

One certificate may cover both standards, or separate documents may provide the evidence. We recommend comparing the scopes side by side before approving the claim.

UL 4703 covers photovoltaic wire, while USE-2 belongs to the service-entrance cable framework under UL 854. These product identities should not be treated as interchangeable merely because both appear in PV applications. [Source: UL Solutions.]

UL 4703 includes several voltage and temperature ratings, so buyers must read the rating of the specific listed wire. Its published scope includes 600, 1,000 and 2,000 V, with dry-temperature categories of 90°C, 105°C, 125°C or 150°C, and 90°C wet. These are scope options, not ratings automatically assigned to every product. [Source: UL 4703.]

A 600 V product cannot be accepted for a 1,500 V DC circuit simply because its description says “solar wire.” Likewise, a high dry-temperature rating does not establish the same permitted operating temperature in wet conditions.

Solar cable standards also need to be separated from conductor sizing. The project still requires an ampacity assessment and a check of termination limitations.

Permitted wiring methods must be checked against the locally adopted code and the cable’s listing. UL 4703 explicitly connects its scope to NEC Article 690 wiring methods and other applicable NEC provisions. [Source: UL 4703.]

For a rooftop project, review the route in sections:

• Within the array: check the requirements for exposed cable and its support.
• At accessible locations: check whether guarding or other protection is required.
• At building entry: check the permitted cable type and wiring method.
• Below ground: verify the conditions permitted by the listing and installation rules.
• At terminations: check conductor compatibility and the equipment’s instructions.

Do not approve an entire route based only on the cable type allowed for one section. If a substitution changes the listing, ratings or wiring method, obtain the project designer’s acceptance and any approval required by the authority having jurisdiction.

Verify a solar cable certificate through the issuing body, then match its scope to the ordered product and delivered markings. A PDF bearing a familiar logo is not enough to complete that check.

For TÜV Rheinland documents, use Certipedia and the certificate or test-mark identification. For UL certification information, use UL Product iQ. Other issuers have their own verification channels. [Sources: TÜV Rheinland and UL Solutions.]

The certificate must cover the exact model, size and rating being supplied, with a traceable connection to the certificate holder. Solar cable standards compliance should be verified at product level rather than inferred from a supplier’s general certificate collection.

A seller’s name can differ from the certificate holder’s name, but the supplier should explain and document the relationship. Private-label arrangements also need to be checked under the relevant certification scheme.

For example, if a certificate schedule covers only 4 mm² and 6 mm², do not assume that it also covers a 10 mm² order. Ask for the applicable scope extension or other acceptable evidence before approving production.

Product certification, ISO 9001, CE marking and RoHS documentation establish different things. None should be used as a blanket substitute for evidence against the specified solar cable standards.

ISO describes ISO 9001 as a quality management system standard. The European Commission explains that CE marking involves the manufacturer’s responsibility for applicable conformity assessment and documentation. RoHS addresses restrictions on certain hazardous substances in electrical and electronic equipment. [Sources: ISO and European Commission.] iso.org

We recommend requesting separate evidence for the questions being assessed: product conformity, supplier management systems and applicable market requirements. This keeps certificate review focused on what each document can actually demonstrate.