UL 67 2023-05 PDF

Full title and description

St UL 67:2023-05 — Standard for Safety: Panelboards. This document contains the requirements, construction and performance criteria, marking and testing procedures used by Underwriters Laboratories (UL) for the evaluation and listing of panelboards and enclosed panelboards used in accordance with the National Electrical Code (NFPA 70).

Abstract

UL 67:2023-05 specifies safety, construction, performance and marking requirements for panelboards intended to control and protect branch and feeder circuits in electrical installations. The standard addresses assemblies supplied as panel only or as complete enclosed panelboards, and includes provisions for electrical ratings, short-circuit withstand, bus construction, enclosure requirements, heat-rise testing, and required labeling. It also identifies equipment excluded from its scope (for example dedicated transfer-switch equipment and factory-wired industrial control panel assemblies).

General information

• Status: Active (current UL standard subject to red-line/revision cycles).
• Publication date: 2023-05 (May 2023).
• Publisher: Underwriters Laboratories (UL Solutions).
• ICS / categories: Electrical engineering — low-voltage distribution equipment; panelboards and enclosed panelboards; conformity to NEC (NFPA 70).
• Edition / version: UL 67:2023-05 (2023 edition / red-line cycle entry).
• Number of pages: Approximately 142 pages (PDF full text count reported in public listings).

Scope

UL 67 covers the safety requirements for panelboards used for the control and protection of electric lighting, appliance branch circuits and power circuits, including feeder-distribution panelboards and panelboard assemblies. The standard excludes distribution equipment whose sole function is automatic or manual transfer of load conductors (referenced to UL 1008) and factory-wired industrial control panel assemblies intended to control industrial processes (referenced to UL 508A). The standard also references related UL requirements for accessories and components used in panelboard assemblies.

Key topics and requirements

• Definitions and classification of "Panelboard" (panel only) versus "Enclosed Panelboard" (panel plus tested enclosure).
• Construction and material requirements for busbars, chassis, and enclosures.
• Ratings and marking: voltage, ampacity, short-circuit current rating and identification markings required for listing.
• Heat-rise and temperature tests to verify current-carrying capacity and insulation integrity.
• Short-circuit withstand and coordination of component interrupting ratings when tested as an assembly.
• Protection and barrier requirements for personnel safety and prevention of accidental contact.
• Requirements for accessory modules in modular panelboard systems and labeling for intended use (e.g., "Suitable for Use as Service Equipment").
• Referenced normative standards (NEC, other UL standards) that apply to associated components and installations.

Typical use and users

UL 67 is used by panelboard manufacturers, third‑party test laboratories, product designers, electrical engineers, specifying consultants, authorities having jurisdiction (AHJs), and contractors. It is applied in the design, testing and certification of panelboards for commercial, industrial and residential building electrical distribution systems where compliance with UL listing and NEC requirements is required.

Related standards

Commonly referenced standards and documents in conjunction with UL 67 include NFPA 70 (National Electrical Code), UL 50 (Enclosures for Electrical Equipment), UL 489 (Molded‑Case Circuit Breakers), UL 1008 (Transfer Switch Equipment), UL 508A (Industrial Control Panels) and relevant CSA/NEMA publications. These cross‑references address enclosure performance, overcurrent device requirements, transfer equipment and industrial control assemblies that UL 67 excludes or interacts with.

Keywords

UL 67; Panelboards; Enclosed panelboards; Panelboard modules; Short‑circuit rating; Busbars; Heat‑rise test; Enclosures; National Electrical Code; UL listing; Electrical distribution.

FAQ

Q: What is this standard?

A: UL 67 is the Underwriters Laboratories safety standard that establishes the construction, performance, testing and marking requirements for panelboards and enclosed panelboards used in electrical distribution systems.

Q: What does it cover?

A: It covers panelboard assemblies for control and protection of branch and feeder circuits, addressing electrical ratings, mechanical construction, thermal and short‑circuit testing, markings and labeling, and related safety features. It also specifies what equipment is outside its scope (for example transfer switches and factory‑wired industrial control panels).

Q: Who typically uses it?

A: Manufacturers of panelboards and load centers, testing and certification bodies, electrical engineers and designers, code officials and contractors who need to ensure equipment is UL‑listed and compliant with NEC requirements.

Q: Is it current or superseded?

A: The referenced edition is UL 67:2023-05 (published May 2023) and is listed as an active UL standard subject to the usual red‑line/revision and CSDS cycles maintained by UL. Users should verify with UL or their listing files for any red‑line changes or later editions.

Q: Is it part of a series?

A: UL 67 is part of UL’s standards covering electrical distribution and related equipment and is commonly used together with other UL standards (for enclosures, circuit breakers, transfer equipment, industrial control panels) and the NEC. It is a foundational UL standard for panelboard product evaluation.

Q: What are the key keywords?

A: Panelboards, enclosed panelboards, busbars, short‑circuit rating, heat‑rise, enclosure, UL listing, NEC (NFPA 70), markings, panelboard modules.