IEC 61558-2-13:2022

Overview

IEC 61558-2-13:2022 is the IEC safety standard for auto-transformers and power supply units incorporating auto-transformers for general applications. It is Part 2‑13 of the IEC 61558 series (group safety publication per IEC Guide 104) and is intended to be used together with IEC 61558‑1:2017. The third edition (2022) updates structure and references to align with IEC 61558‑1, relocates construction descriptions into the general part, and introduces a new symbol for power supply units with linearly regulated outputs. The standard covers electrical, thermal and mechanical safety aspects for stationary or portable, single‑ or polyphase, air‑cooled dry‑type auto‑transformers (encapsulated or non‑encapsulated).

Key topics and requirements

The standard supplements IEC 61558‑1 with particular requirements and tests specific to auto‑transformers and related power supply units. Major technical topics include:

• Ratings and classification (rated supply voltage, frequency, core power and rated output limits)
• Marking and documentation (symbols, type identification and safety information)
• Protection against electric shock and earthing requirements
• Output characteristics: change of input voltage setting, output voltage/current under load, no‑load output voltage and short‑circuit voltage
• Thermal safety: heating limits, thermal testing and resistance to heat
• Electrical safety tests: insulation resistance, dielectric strength and leakage current
• Short‑circuit and overload protection and required protective measures
• Mechanical strength and construction: internal wiring, components, terminals, screws and connections
• Clearances, creepage distances and resistance to tracking, moisture and rusting
• Ingress protection and suitability for general applications (natural or forced cooling)

(Clause numbers and figures in the standard give detailed test procedures and acceptance criteria.)

Practical applications

IEC 61558‑2‑13 is applied when designing, testing or certifying:

• General‑purpose auto‑transformers used in industrial equipment, control panels and mains voltage adjustment applications
• Power supply units that use auto‑transformers or include electronic circuits with autotransformer sections
• Products requiring documented compliance for market access and third‑party certification

The standard is suitable for manufacturers, test laboratories and safety engineers who need to demonstrate conformity for products up to the rated voltages and power levels specified in the document.

Who should use this standard

• Transformer and power‑supply manufacturers and designers
• Electrical safety engineers and compliance officers
• Certification bodies and test laboratories
• OEMs integrating auto‑transformers in equipment

Related standards

• IEC 61558‑1:2017 (general requirements and tests) - use in conjunction with Part 2‑13
• IEC 61558‑2‑16 - applicable for switch‑mode power supply units (in combination with Part 2‑13 where relevant)

For procurement, design and compliance work, consult the full IEC 61558‑2‑13:2022 text and IEC 61558‑1:2017 for complete test methods, limits and normative references.