UL 1562 2020-08 PDF

Full title and description

St UL 1562 2020-08 — UL 1562:2020, "Standard for Transformers, Distribution, Dry-Type — Over 600 Volts". This edition contains the 4th edition of UL 1562 with the Revision Change (Code A) issued August 11, 2020 and specifies construction, performance and testing requirements for dry-type distribution transformers intended for use above 600 V.

Abstract

This standard establishes safety and performance requirements for single‑ and three‑phase dry‑type distribution transformers (solid cast or resin‑encapsulated) intended for primary or secondary voltages above 600 V. It covers design, marking, construction, and required tests (electrical, temperature rise, dielectric and short‑circuit where applicable) for ventilated and non‑ventilated enclosures, and excludes specialty transformers such as instrument, rectifier, arc furnace, mining and certain utility‑controlled units.

General information

• Status: Active (4th edition with Revision Change Code A issued August 11, 2020).
• Publication date: 2020-08-11 (Revision Change date: August 11, 2020).
• Publisher: Underwriters Laboratories (UL).
• ICS / categories: Electrical equipment / transformers; commonly cross‑referenced with protection/fire and electrical standards (examples cited in distributor metadata list ICS 13.220).
• Edition / version: 4th edition — includes Change 08/20 (Revision Change, Code A).
• Number of pages: ~18 pages in the 2020‑08 electronic release (page counts vary by distributor package; earlier print editions listed ~19–22 pages).

Scope

Applies to dry‑type distribution transformers over 600 V (typical primary/secondary voltage range noted in summaries: approximately 601 V up to distribution class voltages such as 35,000 V where applicable). The standard covers construction types including solid cast and resin‑encapsulated dry‑type transformers and addresses installation‑related marking and testing requirements; it does not apply to many specialty or utility‑only transformer types (instrument, rectifier, arc furnace, mining, motor‑starting reactors, step‑voltage regulators, etc.).

Key topics and requirements

• Definitions and classification of dry‑type distribution transformers (single‑ and three‑phase; solid cast and resin‑encapsulated).
• Construction and materials requirements (enclosure types, insulation systems, terminals, clearances and creepage distances).
• Marking, nameplate and installation information required for safe use and conformity with the National Electrical Code.
• Required tests: dielectric tests, temperature‑rise tests, routine factory tests and applicable short‑circuit or impulse tests as specified.
• Performance limits (temperature rise, insulation coordination, ventilation/overheat considerations) and instructions for installation and maintenance.
• Exclusions and special‑purpose transformer exceptions (what is not covered by this standard).

Typical use and users

Used by transformer manufacturers, test laboratories, compliance engineers, product safety managers, OEMs specifying distribution transformers for industrial and commercial installations, and third‑party evaluators performing UL certification or listing. It is referenced by design engineers when specifying dry‑type transformers for switchgear, distribution panels, substations in buildings, and other installations requiring >600 V rated dry transformers.

Related standards

Commonly cross‑referenced standards and industry documents include UL 1561 (dry‑type transformers for lower voltage classes), IEEE transformer standards (for example IEEE C57 series and guidance documents such as IEEE C57.110), NEMA and IEC transformer standards and relevant portions of the National Electrical Code (ANSI/NFPA 70). These related documents are often cited for testing methods, performance calculations and harmonics/non‑sinusoidal load guidance.

Keywords

UL 1562, dry‑type transformer, distribution transformer, resin‑encapsulated, solid cast, >600 V, temperature rise, dielectric test, UL listing, transformer safety, ventilation.

FAQ

Q: What is this standard?

A: UL 1562 is a safety and performance standard published by Underwriters Laboratories that sets requirements for dry‑type distribution transformers rated for use over 600 volts.

Q: What does it cover?

A: It covers construction, marking, required tests and performance limits for single‑ and three‑phase dry‑type distribution transformers (solid cast and resin‑encapsulated) used above 600 V, while excluding certain specialty transformers and utility‑only equipment.

Q: Who typically uses it?

A: Transformer manufacturers, compliance and safety engineers, test labs, OEMs and specifiers who design, build, test or certify dry‑type distribution transformers for industrial and commercial installations.

Q: Is it current or superseded?

A: The referenced edition is the 4th edition with Revision Change (Code A) dated August 11, 2020. Users should verify with Underwriters Laboratories for any subsequent revisions or errata beyond that date to confirm currency.

Q: Is it part of a series?

A: Yes — UL 1562 is part of UL's family of transformer standards (for example UL 1561 for other dry‑type transformer classes and other UL/IEEE/NEMA documents addressing transformers and testing). It is frequently used alongside IEEE C57 series and NEMA guidance.

Q: What are the key keywords?

A: dry‑type, distribution transformer, >600 V, UL 1562, temperature rise, dielectric test, resin‑encapsulated, solid cast, UL listing.