UL 2263 vs UL 2251 vs UL 2231: What They Cover

TL;DR

Different UL standards cover different pieces of your EV charger — they are not interchangeable. UL 2263 certifies the flexible EV cable. UL 2251 covers the plugs, receptacles, and vehicle-side connectors. UL 2231 certifies personnel protection systems (the GFCI-like circuit that prevents electric shock). UL 2594 certifies the complete Electric Vehicle Supply Equipment (EVSE) as a listed product. A "UL 2263-certified" cable is not the same as a "UL Listed" charger — one is a component; the other is a finished-product listing. Always check which standard a product page cites before assuming "UL" means the whole unit is certified.

Table of contents

• The quick decoder — which UL standard covers what
• UL 2263 — the flexible EV cable
• UL 2251 — plugs, receptacles, and vehicle couplers
• UL 2231 — personnel protection systems
• UL 2594 — the complete EVSE as a listed product
• The difference between "certified components" and "listed products"
• How to read a UL mark on an EV charger label
• WenStorm's certificates, decoded
• Frequently asked questions

The quick decoder — which UL standard covers what

Every UL standard for EV charging equipment has a narrow, specific scope. A single EV charger typically involves multiple standards, each authorizing a different piece.

UL standard	What it certifies	What you see on the product
UL 2263	The flexible cable stock used inside EV charging cables (the wire, insulation, and jacket)	"Built with UL 2263-certified cable" on cable and cordset products
UL 2251	Plugs, receptacles, and vehicle couplers (the physical connectors on each end)	"UL 2251 connector" on the plug/coupler spec sheet
UL 2231	Personnel protection systems (the ground-fault protection circuit inside the EVSE)	Referenced in the EVSE's internal safety-listing scope, rarely marketed to consumers
UL 2594	The complete Electric Vehicle Supply Equipment — the whole finished charger	"UL Listed" or "cUL Listed" with the UL logo mark on the finished EVSE

A product may cite one, two, or all four. The number of standards cited does not indicate quality; it indicates which certification pathways the manufacturer completed. A "UL Listed" EVSE (per UL 2594) has been evaluated as a complete assembled product. A cordset that only cites UL 2263 has cable material certified but was not itself submitted for a complete-product listing.

UL 2263 — the flexible EV cable

UL 2263 is the standard for Electric Vehicle (EV) Cable. It applies to the flexible copper cable inside a charging cordset — the same physical wire that runs from the EVSE handle to the vehicle connector, or between the EVSE brick and its plug.

What UL 2263 evaluates:

• Conductor gauge and construction (typically 8 AWG or 10 AWG copper for Level 2 charging)
• Insulation material (rated for continuous EV load and outdoor exposure)
• Cable jacket properties (flexibility, weather resistance, oil resistance, crush resistance)
• Temperature range (typical range −40 °C to +90 °C)
• Voltage rating (typically 300 V or 600 V AC)
• Ampacity (continuous current rating)

What UL 2263 does NOT evaluate:

• The complete assembled cordset (cable + connectors + strain relief + molded ends)
• The EVSE brick or its safety electronics
• The plug/receptacle on either end (that's UL 2251)
• The personnel-protection circuit (that's UL 2231)

A UL 2263 certificate is issued to the cable material manufacturer (typically the OEM producing the cable stock), not to every downstream product that uses the cable. This is why you'll see the exact same UL 2263 certificate number cited by multiple different-branded EV extension cables — they're all using cable material from the same certified stock.

Companion standard for Canada: UL 2263 evaluations often accompany CSA C22.2 No. 332, which is the equivalent Canadian standard for EV cable. A "cULus" or combined Canada-US mark indicates both standards were evaluated in a single certification event. A "cUL" mark alone indicates Canadian certification only.

UL 2251 — plugs, receptacles, and vehicle couplers 

UL 2251 is the standard for Plugs, Receptacles, and Couplers for Electric Vehicles. It covers the physical connectors on either end of an EV charging cable — the plug that connects to the electrical supply, the receptacle, and the vehicle-side coupler (J1772, NACS, or CCS Combo).

What UL 2251 evaluates:

• Mechanical construction of the connector body (materials, tolerances, contact geometry)
• Contact insertion and withdrawal forces
• Wear cycle life (a UL 2251 connector is tested for a minimum number of mate/unmate cycles under continuous current)
• Latching and locking mechanisms (J1772 uses a mechanical latch; NACS uses a locking pin actuated by the vehicle)
• Temperature rise under continuous rated current
• Withstand voltage between contacts

Note: an IP (ingress protection) rating on a connector is a separate specification defined under IEC 60529 — a UL 2251 connector may or may not carry a specific IP rating. Check the product's own certification documentation for its published IP rating.

What UL 2251 does NOT evaluate:

• The cable connected to the connector (that's UL 2263)
• The EVSE electronics behind the connector (that's UL 2594)
• The vehicle's onboard charger

The J1772 connector standard (SAE J1772) and the NACS connector standard (SAE J3400, published December 2023) define the connector's electrical interface and signaling protocol. UL 2251 evaluates the safety and durability of the physical connector hardware that implements those standards.

UL 2231 — personnel protection systems 

UL 2231 is the standard for Personnel Protection Systems for Electric Vehicle Supply Circuits. It covers the ground-fault and shock-protection circuit inside an EVSE — the electronic system that detects a fault and cuts power before it can cause electric shock or fire.

Every listed Level 1 or Level 2 EVSE contains a personnel protection system per UL 2231. This is a separate certification pathway from the complete-EVSE listing (UL 2594) because the personnel protection subsystem can be independently evaluated and certified.

What UL 2231 evaluates:

• Ground-fault current interruption at the trip threshold and response characteristics defined in the standard for EV-charging personnel protection (this is a separate protection class from the Class A GFCI receptacles familiar from bathroom or kitchen wiring — trip thresholds and response times differ across protection classes; UL 2231 defines its own requirements)
• Response time (time from fault detection to power interruption)
• Test-cycle reliability (repeated fault simulation without degradation)
• Self-diagnostic behavior on power-up
• Behavior under abnormal voltage, ground loss, and neutral-loss conditions

How NEC 625.54 relates: NEC 625.54 (in recent code cycles) requires GFCI or Special Purpose GFCI (SPGFCI) protection on receptacles installed for EV charging equipment. The specific requirement — including whether the protection must be at the receptacle itself, whether SPGFCI is acceptable in place of standard GFCI, and how the EVSE's own internal protection interacts with the receptacle rule — varies by NEC edition and by the local jurisdiction that adopted it. Do not assume a UL 2231-listed EVSE automatically eliminates the receptacle-side GFCI requirement. Always check the exact NEC edition adopted by your local authority having jurisdiction before installing an EV-charging receptacle.

What UL 2231 does NOT evaluate:

• Overcurrent protection (that's the branch-circuit breaker in your panel)
• The cable or connector safety (those are UL 2263 and UL 2251)
• The vehicle's onboard fault detection

UL 2594 — the complete EVSE as a listed product 

UL 2594 is the standard for Electric Vehicle Supply Equipment. It evaluates the complete assembled EVSE — the finished product as a listed unit.

What UL 2594 evaluates:

• The full electrical and mechanical safety of the assembled EVSE
• All internal subsystems working together
• Enclosure protection (IP rating, impact resistance, thermal management)
• User-interface safety (display, buttons, indicator lights)
• Behavior under fault conditions (over-temperature, ground fault, overcurrent)
• Compliance with all referenced standards (which typically includes UL 2231 for personnel protection)

When you see "UL Listed" on a wall EVSE or portable charger, it means UL 2594 (or its predecessor UL 2202 for older equipment) was the standard evaluated. The UL 2594 certificate is issued to the manufacturer of the finished EVSE and covers a specific model or model family.

Companion standard: CSA C22.2 No. 280 for the Canadian market — often paired with UL 2594 in a single evaluation event. A "cULus" or combined Canada-US mark indicates dual certification for both markets; "cUL" alone indicates Canadian certification only.

Scope distinction from UL 2202: UL 2594 is the principal standard for AC Level 1 and Level 2 EVSE — the equipment consumers use for home charging. UL 2202 is a separate current standard covering DC charging equipment (DC fast chargers). Both standards remain published and current — they are not one replacing the other. If a listing cites UL 2202, that typically indicates DC-rated equipment; UL 2594 typically indicates AC-rated equipment.

The difference between "certified components" and "listed products" 

This is the distinction most product pages and marketing pages blur.

A "certified component" is a subassembly (cable material, connector, protection module) that has been evaluated against a specific UL standard and can be used inside a larger assembled product. The certificate is issued to the component maker.

A "listed product" is a complete finished device (EVSE, cordset assembly, wall charger) that has been evaluated as a whole against a product-level standard, with UL Follow-Up Services surveilling ongoing production.

Why the distinction matters:

• A cable that is "built with UL 2263-certified cable material" tells you the cable stock is certified. It does not tell you the finished cable assembly (cable + molded ends + strain relief) has been submitted to UL as a complete listed product.
• A "UL Listed" EVSE tells you the finished product is a listed unit under UL 2594. It should carry the UL mark on the physical product itself, not just on the cable.
• A product page that says "UL Certified" without naming which standard is telling you very little. Always look for the specific standard (UL 2263, 2251, 2231, 2594) and the certificate number.

Both categories are legitimate. A UL 2263 cable-material certificate is a real, verifiable certification — the cable material genuinely meets the standard. The gap is only when a marketing page implies component-level certification means product-level listing, or vice versa.

How to read a UL mark on an EV charger label

When you look at an EV charger product page or the physical product's label, decode the certification statement in this order:

1. Find the specific standard cited. Is it UL 2263, UL 2251, UL 2231, UL 2594, or "UL Listed" (which usually implies UL 2594 for a finished EVSE)? A general "UL Certified" without a number is ambiguous.
2. Identify what physical component the standard applies to. UL 2263 → the cable. UL 2251 → the connectors. UL 2594 → the whole EVSE. If the statement says "UL 2263-certified cable" on a wall EVSE spec page, that certifies the cable, not the EVSE.
3. Look for a certificate number. UL certificates have identifiers like UL-US-2407470-0 (a US certificate) or UL-CA-2406509-0 (a Canadian certificate). You can look these up on UL Product iQ at productiq.ulprospector.com to verify the certificate exists, its scope, and its expiration.
4. Check the certificate holder. UL certificates are issued to a specific company. If the certificate holder is a component OEM (a cable manufacturer, for example) rather than the brand selling the finished product, that's a signal you're looking at a component certification, not a product listing.
5. Compare with the equivalent ETL mark. The ETL Listed Mark is issued by Intertek — a separate Nationally Recognized Testing Laboratory (NRTL) recognized by OSHA. The ETL name comes from Intertek's historical Electrical Testing Laboratories division. An "ETL Listed" product evaluated against a UL standard (like UL 2594) is functionally equivalent to a UL Listed product for OSHA and electrical-inspection purposes. The two marks are not interchangeable in a claim ("UL Listed" ≠ "ETL Listed") but both are valid third-party safety listings.

Common misreadings to avoid:

• Reading "UL 2263-certified cable" as "UL Listed charger." The first is a cable-material claim; the second is a finished-product listing.
• Assuming a UL mark on the cable means the connectors are also UL-certified. Each component has its own certification.
• Confusing "UL Recognized Component" (a component evaluated for use inside a larger listed assembly) with "UL Listed" (a finished product). Both use UL marks but at different scopes.

WenStorm's certificates, decoded

We publish our certificates on the WenStorm Certification Center. Here is what each one actually covers:

Certificate	Standard	Certificate holder	What it certifies	Covers which WenStorm products
UL-US-2407470-0	UL 2263 (US)	Hichain Electricity (Zhaoqing) — our OEM cable supplier	The EV cable material used inside WenStorm extension cables (models EVE and EVJE)	Built with UL 2263-certified cable material: J1772 Extension Cable, Tesla/NACS Extension Cord
UL-CA-2406509-0	CSA C22.2 No. 332 (Canada)	Hichain Electricity (Zhaoqing)	Same cable material for the Canadian market	Same extension cable products for Canada
ETL Authorization (Intertek)	UL 2594 / CSA C22.2 No. 280	WenStorm	The complete AC EV Charger listings for models Z4A / Z7A / Z7B / BV Series	Level 2 Portable EV Charger, Level 1 Portable EV Charger
TÜV Rheinland CB	IEC 62196-1 and IEC 62196-2	WenStorm	International AC EV connector standards for the specific listed models (CW-16S / CW-16T / CW-32S / CW-32T)	Applies to the specific connector model families listed; not a certification of every connector variant on every WenStorm product

What this means when you buy from WenStorm:

• Our extension cables are built with UL 2263-certified cable material at the cable-material level. We do not currently hold a finished-assembly UL Listing for the extension cable products; we hold the cable-material certificate through our OEM supplier. This wording appears on our product pages and in this article intentionally — we describe what is verifiably certified and no more.
• Our portable Level 1 and Level 2 EV chargers are ETL Listed as complete assembled EVSEs under UL 2594 / CSA C22.2 No. 280. The ETL Listing is a finished-product listing recognized by OSHA and by electrical inspectors in the US and Canada.
• Selected WenStorm connector models (CW-16S / CW-16T / CW-32S / CW-32T) are separately certified under IEC 62196-1 and IEC 62196-2 for the international market. NACS is standardized separately under SAE J3400 (published December 2023); our public Certification Center does not currently list a distinct NACS-specific IEC certificate, so a broad claim of "all our NACS connectors are IEC-certified" would overstate what the published certificates authorize.

The finished-product listings this article references:

If you want to verify any of these, the certificate numbers above can be looked up in UL Product iQ or Intertek's directory. We publish the full documents in the Certification Center so nobody has to take our word for it.

Frequently asked questions 

Is UL 2263 the same as "UL Listed"?

No. UL 2263 is the standard for EV cable material — a component-level certification. "UL Listed" typically refers to a finished-product listing under UL 2594 (for the complete EVSE). A product cited only as "UL 2263-certified" has certified cable material; it may or may not also hold a complete-product listing.

What's the difference between UL and ETL for EV chargers?

Both UL (Underwriters Laboratories) and the ETL Listed Mark (issued by Intertek — the ETL name comes from Intertek's historical Electrical Testing Laboratories division) are Nationally Recognized Testing Laboratories (NRTLs). An ETL Listing under a UL standard (like UL 2594) is functionally equivalent to a UL Listing for OSHA and electrical-inspection purposes. The marks are different but the underlying evaluation is against the same standard.

Do I need to check UL certification when buying an EV charging cable?

Yes — but check the specific standard cited, not just whether "UL" appears somewhere. For a finished EVSE, look for UL Listed or ETL Listed to UL 2594. For a standalone cable or cordset accessory, look for UL 2263 on the cable material. For a personnel-protection circuit inside a charger, UL 2231 is the reference. A page that says "UL Certified" without a specific standard number is not giving you enough information to verify what's actually certified.

What do the "cUL" and "cULus" marks mean?

"cUL" denotes Canadian certification only — the product was evaluated against the equivalent Canadian standard (e.g. CSA C22.2 No. 280 for EVSE, or CSA C22.2 No. 332 for EV cable). "cULus" (or the combined Canada-US marking) indicates the product was evaluated for both markets in a single certification event. If a product carries only the "cUL" mark, it is certified for the Canadian market; look for "cULus" or an equivalent combined mark to confirm dual certification.

Can I trust "UL Recognized Component" the same as "UL Listed"?

They are different. "UL Recognized Component" means a subassembly has been evaluated for use inside a larger listed product — the component is safe to use inside a listed assembly, but it's not itself a finished consumer product. "UL Listed" means the complete finished product has been evaluated. Both are valid but they apply at different levels.

Where can I look up a UL certificate number to verify it exists?

UL certificates are searchable at productiq.ulprospector.com. Enter the certificate number (like UL-US-2407470-0) and you can see the standard, the holder, the scope, and the current status. This is the same directory that electrical inspectors and specifiers use.

Does a UL-certified cable mean the whole extension cable assembly is UL-certified?

No. A UL 2263 certificate covers the EV cable — the flexible wire itself, its insulation, and its jacket, evaluated as cable stock. The finished extension cable assembly (cable + molded connector ends + strain relief) is a separate product-level scope that would require its own certification (typically to a cordset or accessory standard, or included in an EVSE listing). Always distinguish "built with UL 2263-certified cable" from "UL Listed extension cable."

What UL standard applies to portable Level 1 chargers?

Portable Level 1 EVSEs are evaluated to the same UL 2594 standard as Level 2 units — UL 2594 covers Electric Vehicle Supply Equipment in general, not by power level. The personnel-protection circuit inside them is evaluated to UL 2231. The cable is UL 2263. Same three standards apply regardless of whether the charger is rated for 16A Level 1 or 32A Level 2.

The buying takeaway

When you're comparing EV chargers or extension cables, the certification statement matters less than knowing what it actually authorizes. A product that transparently says "built with UL 2263-certified cable material (Cert. UL-US-2407470-0)" is telling you something specific and verifiable. A product that says "UL Certified!" without a standard number or certificate reference is telling you less than you might think.

If you're shopping for equipment across the WenStorm line, our J1772 Extension Cable and Tesla/NACS Extension Cord both use UL 2263-certified cable material at the cable level. Our Level 1 and Level 2 portable chargers are ETL Listed as complete EVSEs to UL 2594. For everything else — connector certifications, IP ratings, international marks — the Certification Center has the full document list.

Related reading

• Can You Use an Extension Cord With an EV Charger? — the full safety framework including NEC 625.17(C) authority
• EV Extension Cable Buyer's Guide: J1772 vs NACS, Length, and What Not to Do — the buying-decision walkthrough with voltage-drop math
• Is a 25-Foot EV Charger Cable Long Enough? — length-planning framework
• WenStorm Certification Center — the full document list