UL 2231-1 2021-09 PDF

Full title and description

St UL 2231-1 2021-09 — Standard for Personnel Protection Systems for Electric Vehicle (EV) Supply Circuits; Part 1: General Requirements. This document sets out the general requirements, definitions and functional criteria for personnel protection systems (PPS) that reduce the risk of electric shock associated with EV charging circuits and that interact with charging equipment and vehicles.

Abstract

This part of UL 2231 provides general requirements for design, performance and testing of protective elements used to prevent electric shock in electric vehicle supply circuits. It covers functional requirements for ground-fault/insulation monitoring, charge-circuit interrupting devices, isolation monitoring/interruption and related compatibility features between vehicle and charging equipment. The edition referenced here was published/issued in September 2021.

General information

• Status: Active (published/released document used as the general-requirements part of the UL 2231 family).
• Publication date: September 16, 2021 (edition/publication date shown for the 2021 release).
• Publisher: Underwriters Laboratories (UL).
• ICS / categories: Electrical safety, personnel protection systems for EV supply circuits, EV charging equipment safety (electrotechnical safety / EVSE safety category).
• Edition / version: Edition 2 (document commonly referenced as UL 2231-1:2021 / second edition revisions reflected in 2021 publication metadata).
• Number of pages: 22 pages (published PDF length as listed in standard distributors).

Scope

UL 2231-1 establishes the scope, definitions and general functional/performance requirements for personnel protection systems incorporated into electric vehicle supply circuits and charging systems. It applies to devices and systems intended to detect hazardous ground faults, loss of isolation, or other conditions that could expose persons to electric shock during charging operations and to the information and marking needed for safe integration with charging equipment and vehicles. The standard clarifies interfaces and compatibility expectations between PPS components, charging equipment and vehicles and identifies the types of circuits and voltage/frequency ranges to which the general requirements apply. It does not replace product-specific requirements found in Part 2 (particular requirements) or other product standards; certain low-voltage GFCI requirements covered by national electrical codes are outside its scope.

Key topics and requirements

• Definitions and terminology for PPS components (e.g., charge-circuit interrupting devices, isolation monitors/interrupters, accessible parts).
• Functional performance requirements for ground-fault detection and interruption, and for isolation monitoring and response.
• Compatibility criteria and interface requirements between vehicles and EV supply equipment (communication, ratings and expected behaviors).
• Testing and verification methods to demonstrate PPS performance under fault, transient and environmental conditions.
• Marking, instructions and documentation requirements to ensure safe installation, use and maintenance.
• Limitations and exclusions — e.g., not intended to replace certain GFCI requirements for standard branch-circuit protection defined in national electrical codes.

Typical use and users

Primary users include EVSE (charging equipment) manufacturers, vehicle electrical-system designers, component suppliers of protective devices (CCIDs, isolation monitors), test laboratories, certification bodies and safety engineers responsible for compliance and product integration. Regulatory and standards groups, as well as procurement and compliance teams in EV infrastructure projects, also reference this standard when specifying personnel-protection performance.

Related standards

Commonly referenced alongside UL 2231-1 are: UL 2231-2 (Part 2: particular requirements for protection devices used in charging systems), UL 2594 (Electric Vehicle Supply Equipment), UL 2251 (Plugs, Receptacles and Couplers for EVs), UL 2202 (DC charging equipment), relevant sections of the National Electrical Code (NEC, e.g., Article 625), and international standards such as IEC 61851 and ISO 6469 where jurisdictional harmonization is required.

Keywords

UL 2231-1; personnel protection system; PPS; electric vehicle supply circuits; EVSE safety; ground-fault detection; isolation monitoring; charge-circuit interrupting device; EV charging; protective devices; compatibility; electrical safety.

FAQ

Q: What is this standard?

A: UL 2231-1 is the general-requirements part of the UL 2231 family addressing personnel protection systems for electric vehicle supply circuits; it specifies definitions, functional requirements and test guidance for devices and systems that protect people from electric shock during EV charging.

Q: What does it cover?

A: It covers general functional and performance requirements for ground-fault/insulation monitoring, isolation-monitoring/interruption and charge-circuit interrupting behavior, along with marking, instructions and compatibility expectations between charging equipment and vehicles. It describes test conditions and limits but defers device-specific construction/performance details to Part 2 and other product standards.

Q: Who typically uses it?

A: EV charging equipment manufacturers, vehicle electrical-system designers, component suppliers (protective devices), independent test labs and certification authorities, and safety/compliance engineers. Procurement and specification teams for EV infrastructure also use it to set personnel-protection requirements.

Q: Is it current or superseded?

A: The version referenced here was published/issued on September 16, 2021 and is treated as the current published general-requirements document for UL 2231-1. Note: regulatory treatment can vary — for example, OSHA published actions in 2021 indicating UL 2231-1 is a component standard (not an end-product standard) and therefore was removed from the OSHA NRTL Program's list of appropriate test standards for NRTL recognition purposes; that administrative action does not by itself alter the technical content of the UL document but affects how it is used in certain regulatory certification contexts.

Q: Is it part of a series?

A: Yes — UL 2231 is a multi-part family. Part 1 (UL 2231-1) contains the general requirements; Part 2 (UL 2231-2) contains particular requirements for protection devices used in charging systems. Other EV-related UL standards (e.g., UL 2594, UL 2251, UL 2202) are frequently used together with the 2231 series.

Q: What are the key keywords?

A: Personnel protection system, EV supply circuit, ground-fault detection, isolation monitoring, charge-circuit interrupting device, EVSE safety, UL 2231-1, protective device requirements.