UL 1310 2022-06 PDF

Full title and description

St UL 1310 2022-06 — Standard for Safety: Class 2 Power Units (UL 1310, 7th Edition with June 9, 2022 editorial change). This UL safety standard specifies performance, construction, testing, marking and installation requirements for power units whose outputs are identified as Class 2 under the National Electrical Code (NEC/NFPA 70).

Abstract

UL 1310 defines safety requirements for Class 2 power units and small battery chargers that provide energy-limited low-voltage outputs intended to reduce fire and shock risk. The standard sets limits for output voltage and energy, prescribes protective measures (insulation, temperature limits, fault protection), and establishes the tests and markings needed for UL Listing of Class 2 power supplies used in consumer, commercial and industrial equipment.

General information

• Status: Active / Current (UL Listed standard).
• Publication date: 7th Edition originally published March 9, 2018; editorial change issued June 9, 2022 (commonly referenced as 2022-06 change to Ed. 7).
• Publisher: Underwriters Laboratories (UL).
• ICS / categories: Electrical engineering (ICS 29) — power supplies, converters and rectifiers; safety of electrical equipment; NEC Class 2 sources.
• Edition / version: 7th Edition (Ed. 7 — 2018) with Change dated June 9, 2022.
• Number of pages: Approximately 117 pages (edition package and redline/change documents may vary in length).

Scope

UL 1310 covers indoor and outdoor Class 2 power supplies and battery chargers that provide energy-limited low-voltage outputs in accordance with the National Electrical Code (NEC). Typical scope items include direct plug-in, cord- and plug-connected, and permanently connected units intended for branch circuits of nominal 120/240 V (or up to 600 V for permanently connected units). The standard limits maximum outputs (for example, outputs that do not exceed the Class 2 voltage/energy levels specified by NEC — commonly cited limits include AC peak and DC continuous thresholds) and excludes products covered by other more specific standards (e.g., larger power units covered by UL 1012, certain battery chargers, and specialized lighting or landscape systems).

Key topics and requirements

• Definition and classification of Class 2 power units and permitted output types (AC or DC) and configurations (plug-in, cord-connected, permanently connected).
• Maximum output energy and voltage limits consistent with NEC Class 2 (energy-limited outputs to reduce shock/fire risk).
• Construction and materials requirements: insulation, enclosures, component ratings, flame-retardant materials and creepage/clearance considerations.
• Electrical protection: overcurrent, short-circuit, temperature/overtemperature protection and required fail-safe behavior.
• Temperature-rise and thermal testing for components and overall assembly under normal and fault conditions.
• Dielectric (hi-pot) and leakage current testing to verify basic and reinforced insulation as applicable.
• Mechanical and environmental tests: strain/strain-relief, humidity, corrosion where applicable, and mechanical strength.
• Marking, labeling and instructions: output ratings, Class 2 identification, installation instructions, and warnings required for UL Listing.
• Specific test methods and acceptance criteria for verifying compliance (endurance, abnormal operation, fault simulation).

Typical use and users

Manufacturers and designers of low-voltage power supplies and LED/lighting drivers, small battery chargers, OEMs integrating Class 2 power units into equipment, compliance and safety engineers, test laboratories and certification bodies use UL 1310 to design, test and certify products intended to operate as NEC-defined Class 2 sources. Buyers, procurement teams, and regulatory reviewers also reference the standard when specifying safe, energy-limited power sources.

Related standards

Examples of standards commonly referenced with UL 1310: UL 1012 (Power Units Other Than Class 2), CAN/CSA C22.2 standards for power supplies (including C22.2 No. 223 where applicable), NFPA 70 (National Electrical Code), UL standards for battery chargers (UL 1236), and other UL/IEC product safety and transformer standards. End‑product or application standards (and modern IEC/EN equivalents such as IEC 61558 or IEC 62368 series where applicable) may impose additional or differing requirements.

Keywords

UL 1310, Class 2, Class 2 power unit, power supply, low-voltage, energy-limited, NEC Class 2, Underwriters Laboratories, safety standard, battery charger, marking, dielectric test, temperature rise, short-circuit protection.

FAQ

Q: What is this standard?

A: UL 1310 is Underwriters Laboratories' Standard for Safety for Class 2 Power Units; it defines safety, construction and test requirements for energy-limited low-voltage power supplies that qualify as NEC Class 2 sources.

Q: What does it cover?

A: It covers indoor and outdoor Class 2 power supplies and small battery chargers (plug-in, cord-connected and permanently connected types) providing outputs that meet NEC Class 2 voltage/energy limits, and specifies tests, protective measures, markings and instructions needed for UL Listing.

Q: Who typically uses it?

A: Product designers, manufacturers of LED drivers and low-voltage adapters, OEMs, compliance engineers, test labs and certification bodies, and procurement/regulatory personnel specifying Class 2 power sources.

Q: Is it current or superseded?

A: As presented here, the active edition is the 7th Edition (originally dated March 9, 2018) with an editorial/technical change issued June 9, 2022. That 2018/2022 package is treated as the current UL 1310 reference; users should confirm with UL for any later amendments or revisions issued after June 9, 2022.

Q: Is it part of a series?

A: UL 1310 is part of UL's family of electrical safety standards addressing power supplies and chargers. Related UL documents include UL 1012 (power units other than Class 2), various UL transformer and charger standards, and national codes such as NFPA 70 (NEC) which define the Class 2 concept.

Q: What are the key keywords?

A: Class 2, power unit, UL 1310, energy-limited, low-voltage power supply, safety standard, NEC Class 2, battery charger, marking, dielectric testing.