IEC 61558-2-23:2024

Overview

IEC 61558-2-23:2024 is the 3rd edition of the IEC safety standard for transformers and power supply units for construction sites. It covers safety requirements and tests for transformers, reactors and power supply units (including those that incorporate electronic circuits) intended for use on construction sites. This edition replaces the 2010 edition, aligns structure and references with IEC 61558-1:2017, introduces a new symbol for linearly regulated outputs, and has group safety publication status under IEC Guide 104.

Key topics and requirements

This standard details particular requirements and tests relevant to construction-site equipment. Major technical topics include:

• Scope, ratings and classification for construction-site transformers and power supply units.
• Marking and information requirements for safe use, selection and service.
• Electrical safety: protection against electric shock, touch current and protective-earthing conductor current.
• Insulation and dielectric tests: insulation resistance, dielectric strength and winding separation.
• Thermal performance and ageing: temperature-rise tests and accelerated ageing procedures.
• Short-circuit and overload: test methods for inherently and non-inherently short-circuit-proof transformers.
• Mechanical robustness: impact, shock and vibration tests for portable and fixed transformers.
• Ingress protection and environmental tests: IP tests, humidity treatment and moisture resistance for construction conditions.
• Construction and components: internal wiring, terminals, protective earthing provisions, creepage/clearance distances, flammability and resistance to heat, fire and tracking.
• Portable-specific requirements: pin-connected (plug) transformers, strain on socket outlets and use in harsh or irregular conditions.
• Measurement and test procedures: procedures for series testing, measurement of creepage/clearances and other normative test annexes.

Practical applications and users

IEC 61558-2-23:2024 is used by:

• Manufacturers and designers of transformers, portable power supply units and site distribution gear to demonstrate safety compliance.
• Test laboratories and conformity assessors performing type and routine testing against IEC requirements.
• Procurement and site safety professionals selecting compliant power equipment for construction projects.
• Certification bodies and regulators issuing approvals and ensuring equipment meets recognized safety practices for construction environments.

Use cases include designing robust portable transformers, specifying power supply units for temporary site distribution, and ensuring products survive mechanical stress, moisture and electrical faults common on construction sites.

Related standards

• IEC 61558-1:2017 (general requirements and tests) - the normative reference for general safety principles and test methods.
• Other IEC product and IP-related standards referenced within IEC 61558-2-23:2024 for specific tests and symbols.

Keywords: IEC 61558-2-23:2024, transformers for construction sites, power supply units, safety standard, construction site power, portable transformers, electrical safety testing.