SAE J3400-2023
NACS Electric Vehicle Coupler

Standard No.

SAE J3400-2023

Release Date

2023

Published By

Society of Automotive Engineers (SAE)  US  /  SAE

Status

Be replaced

Replace By

SAE J3400_202312

Latest

SAE J3400_202409

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Introduction

Standard Background and Technological Evolution

SAE J3400 (formerly NACS) is a charging connector system developed by Tesla, which officially became an SAE standard in 2023. Its development aimed to solve the incompatibility issues of various charging interfaces on the market and promote the unification of charging infrastructure in North America. This standard covers DC and single-phase AC charging at a voltage level of 1000V and is compatible with older NACS devices with a rated voltage of 500V, ensuring backward compatibility.

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Standard Framework Comparison

Dimensions	SAE J3400 (NACS)	SAE J1772 (Type 1)	CCS (Combined Charging System)
Voltage Ratings	AC: 120-277V, DC: 1000V max	AC: 120-240V, DC: Not directly supported (requires CCS)	AC: 120-240V, DC: 1000V max
Communication Methods	PWM/PLC (DIN 70121/ISO) 15118), optional LIN-CP, SW-CAN-CP (compatible with older models)	PWM (AC only), optional PLC (CCS)	PWM/PLC (DIN 70121/ISO 15118)
Mechanical Design	5 contacts (2 power + CP + Prox + GND), compact, manual/automatic locking	5 contacts, larger size, manual locking	7 contacts (2 power + CP + Prox + GND + 2 signal), larger size
Compatibility	Compatible with 500V older NACS, can be used with J1772/CCS via adapter	Not directly compatible with NACS	Not directly compatible with NACS
Main application areas	North America (Tesla-led, gradually opening)	North America (excluding Tesla)	North America (CCS1), Europe (CCS2)

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Key terms and professional interpretations

Proximity Detection: Identification of connector insertion status is achieved through a resistor network (R4/R5/R6). The SAE J3400 retains the "unlocked" voltage threshold (approximately 2.77V) compatible with SAE J1772 to ensure safe identification. During DC charging, the EVSE must respond to an emergency stop within 10ms. Control Pilot (CP): Charging parameters are transmitted using PWM signals. During DC charging, a PLC is superimposed to achieve high-speed communication (ISO 15118). The standard requires a duty cycle of 10-96% for AC charging and 5% for DC charging (for PLC link establishment). Interoperability: The standard explicitly supports older SW-CAN-CP communication EVSEs, avoiding conflicts through delayed S2 closure. EVs must be able to distinguish between AC/DC power supply types (IP communication alone is not permitted). Implementation Recommendations: For EVSE manufacturers: 1000V DC design is preferred, and support for DIN 70121/ISO 15118-2 protocols is required. The resistance accuracy of the proximity detection circuit should be ≤±3% (±1% is recommended for DC applications). The vehicle must meet the North American EVSE safety standards (UL 2231/CSA C22.2 No. 281) and FCC EMC requirements. For electric vehicle manufacturers: The on-board charger (OBC) must support ANSI C84.1 voltage range B (104-293V) for compatibility with 277V commercial power supplies. Safety policies should meet ISO 26262 ASIL D level, particularly preventing contactor malfunction when AC/DC pins are shared. Mechanical lock-up position monitoring should be maintained to ensure immediate termination of charging upon detection of unlocking. For more technical details, please refer to the original SAE J3400 standard and subsequent revisions.

SAE J3400-2023 Referenced Document

• ANSI C84.1 American National Standard for Electric Power Systems and Equipment—Voltage Ratings (60 Hz)
• CFR 40 Protection of environment. Part98:Mandatory greenhouse gas reporting. Subpart I:Electronics manufacturing. Section98.98:Definitions.
• CFR 47 Telecommunication. Part97:Amateur radio service. Subpart F:Qualifying examination systems. Section97.519:Coordinating examination sessions.
• CSA C22.1 2021 Canadian Electrical Code
• DIN SPEC 70121 Electromobility - Digital communication between a d.c. EV charging station and an electric vehicle for control of d.c. charging in the Combined Charging System; Text in English
• DIN SPEC 70122 Electromobility - Conformance tests for digital communication between a d.c. EV charging station and an electric vehicle for control of d.c. charging in the Combined Charging System; Text in English, only on CD-ROM / Note: CD-ROM
• IEC 61851-1 Corrigendum 1 - Electric vehicle conductive charging system - Part 1: General requirements
• IEC 61851-21-1 Electric vehicle conductive charging system - Part 21-1: Electric vehicle on-board charger EMC requirements for conductive connection to an AC/DC supply
• IEC 61851-21-2 Electric vehicle conductive charging system - Part 21-2: Electric vehicle requirements for conductive connection to an AC/DC supply - EMC requirements for off-board electric vehicle charging systems
• IEC 62196-1 Plugs, socket-outlets, vehicle connectors and vehicle inlets - Conductive charging of electric vehicles - Part 1: General requirements
• IEC 62196-2 Plugs, socket-outlets, vehicle connectors and vehicle inlets - Conductive charging of electric vehicles - Part 2: Dimensional compatibility requirements for AC pin and contact-tube accessories
• IEC 62196-3 Plugs, socket-outlets, vehicle connectors and vehicle inlets - Conductive charging of electric vehicles - Part 3: Dimensional compatibility requirements for DC and AC/DC pin and contact-tube vehicle couplers
• IEC TS 62196-3-1 Plugs,socket-outlets, vehicle connectors and vehicle inlets - Conductive charging of electric vehicles - Part 3-1: Vehicle connector, vehicle inlet and cable assembly for DC charging intended to be us
• IEEE 100 CD STANDARDS DICTIONARY: GLOSSARY OF TERMS and DEFINITIONS (ISBN: 978-0-7381-5739-9)
• IEEE 1547 Interconnecting Distributed Resources with Electric Power Systems Amendment 1
• IEEE 2030.5 IEEE Standard for Smart Energy Profile Application Protocol
• ISO 11451-2 Road vehicles - Vehicle test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 2: Off-vehicle radiation sources
• ISO 15118-1 Road vehicles Vehicle to grid communication interface Part 1: General information and use case definition
• ISO 15118-2 Road vehicles -- Vehicle-to-Grid Communication Interface -- Part 2: Network and application protocol requirements
• ISO 15118-3 Road vehicles -- Vehicle to grid communication interface -- Part 3: Physical and data link layer requirements
• ISO 15118-4 Road vehicles
• ISO 15118-5 Road vehicles Vehicles to grid communication interface Part 5: Physical and data link layer conformance tests
• ISO 17409 Electrically propelled road vehicles — Conductive power transfer — Safety requirements
• ISO 17987-1 Road vehicles — Local Interconnect Network (LIN) — Part 1: General information and use case definition
• ISO 17987-2 Road vehicles - Local Interconnect Network (LIN) - Part 2: Transport protocol and network layer services
• ISO 17987-3 Road vehicles - Local Interconnect Network (LIN) - Part 3: Protocol specification
• ISO 17987-4 Road vehicles - Local Interconnect Network (LIN) - Part 4: Electrical physical layer (EPL) specification 12 V/24 V
• ISO 17987-6 Road vehicles — Local Interconnect Network (LIN) — Part 6: Protocol conformance test specification
• ISO 17987-7 Road vehicles — Local Interconnect Network (LIN) — Part 7: Electrical physical layer (EPL) conformance test specification
• ISO 20653 Road vehicles — Degrees of protection (IP code) — Protection of electrical equipment against foreign objects, water and access
• ISO 26262 ISO 26262 Second Edition: Explanatory Book
• ISO 5474-1 Electrically propelled road vehicles
• ISO 5474-2 Electrically propelled road vehicles - Functional and safety requirements for power transfer between vehicle and external electric circuit - Part 2: AC power transfer
• ISO 5474-3 Electrically propelled road vehicles
• ISO 6469-3 Electrically propelled road vehicles — Safety specifications — Part 3: Electrical safety
• ISO/TR 17987-5 Road vehicles - Local Interconnect Network (LIN) - Part 5: Application programmers interface (API)
• NEMA WD 6 WIRING DEVICES - DIMENSIONAL SPECIFICATIONS
• NFPA 70 National Electrical Code
• SAE J1211 Handbook for Robustness Validation of Automotive Electrical/Electronic Modules
• SAE J1772 SAE Electric Vehicle and Plug-in Hybrid Electric Vehicle Conductive Charge Coupler*， 2026-06-05 Update
• SAE J2012 Diagnostic Trouble Code Definitions
• SAE J2344 Guidelines for Electric Vehicle Safety
• SAE J2411 Single Wire CAN Network for Vehicle Applications
• SAE J2847/2 Communication Between Plug-in Vehicles and Off-Board DC Chargers
• SAE J2847/3 Communication for Plug-in Vehicles as a Distributed Energy Source
• SAE J2847/5 Communication Between Plug-In Vehicles and Customers
• SAE J2931/1 Digital Communications for Plug-in Electric Vehicles
• SAE J2931/4 Broadband PLC Communication for Plug-in Electric Vehicles
• SAE J2953/1 Plug-In Electric Vehicle (PEV) Interoperability with Electric Vehicle Supply Equipment (EVSE)
• SAE J2953/2 Test Procedures for the Plug-In Electric Vehicle (PEV) Interoperability with Electric Vehicle Supply Equipment (EVSE)
• SAE J3068 Electric vehicle power transmission system using three-phase coupler
• SAE J3072 Interconnection Requirements for Onboard, Grid Support Inverter Systems
• SAE USCAR2 Performance Specification for Automotive Electrical Connector Systems
• UL 2202 UL Standard for Safety DC Charging Equipment for Electric Vehicles
• UL 2231-1 UL Standard for Safety Personnel Protection Systems for Electric Vehicle (EV) Supply Circuits: General Requirements
• UL 2231-2 UL Standard for Safety Personnel Protection Systems for Electric Vehicle (EV) Supply Circuits: Particular Requirements for Protective Devices for Use in Charging Systems
• UL 2251 Plugs, receptacles and cable couplers for electric vehicles
• UL 2263 ANSI/UL 2263-2022
• UL 2594 UL Standard for Safety Electric Vehicle Supply Equipment
• UL 50 UL Standard for Safety Enclosures for Electrical Equipment, Non-Environmental Considerations
• UL 943 STANDARD FOR SAFETY Ground-Fault Circuit-Interrupters

SAE J3400-2023 history

• 0000 SAE J3400_202409
• 2024 SAE J3400-2024 North American Electric Vehicle Charging System (NACS)
• 0000 SAE J3400_202312
• 2023 SAE J3400-2023 NACS Electric Vehicle Coupler

Standard and Specification