IEC 61558-2-5:2010

Overview

IEC 61558-2-5:2010 is an international standard published by the International Electrotechnical Commission (IEC) focusing on the safety requirements for transformers, reactors, power supply units, and their combinations, specifically designed for shavers. This standard outlines the particular requirements and test methods for shaver transformers, power supply units that incorporate shaver transformers, and shaver supply units, including those with electronic circuit integration.

This standard represents the second edition, replacing the original 1997 publication, and incorporates important updates aligning it with IEC 61558-1:2005. It also expands the scope to cover power supply units. Its application ensures the devices meet stringent safety criteria in electrical, thermal, mechanical, and chemical aspects.

Key Topics

• Scope of Application
  IEC 61558-2-5 applies to stationary, single-phase, air-cooled dry-type transformers used primarily in shaver power supplies. It covers both encapsulated and non-encapsulated windings with operational frequencies up to 500 Hz. For switch mode power supply units (SMPS) with frequencies higher than 500 Hz, this standard works alongside IEC 61558-2-16, applying the more stringent requirements where conflicts arise.

• Safety Requirements
  The standard focuses on ensuring protection against electric shock through requirements for double or reinforced insulation, mechanical strength, and resistance to heat, fire, and moisture ingress. It also sets parameters on electrical ratings, including input voltage not exceeding 250 V AC and output power rating between 20 VA and 50 VA.

• Testing Procedures
  IEC 61558-2-5 specifies rigorous test conditions such as no-load and short-circuit voltage assessments, insulation resistance, dielectric strength, heating, mechanical durability, and protection against dust and moisture. Testing ensures compliance with thermal limits, internal wiring integrity, and component suitability under operational stress.

• Marking and Information
  The standard mandates clear identification and comprehensive markings on the devices to provide users and installers with necessary information including ratings, input voltage settings, and safety instructions.

Applications

IEC 61558-2-5 caters specifically to electric shaver manufacturers and suppliers who require their transformers and power supplies to comply with international safety standards. These transformers are often embedded in bathroom appliances, mirrors, and luminaires with integrated shaver sockets. The standard provides assurance that the products are safe for consumer use in wet or humid environments where electrical safety is critical.

In addition to consumer appliances, this standard can be a crucial reference for regulatory bodies, testing laboratories, certification entities, and product designers focused on safe and reliable shaver power supply units. It supports manufacturers in meeting national regulations by aligning with IEC’s internationally recognized safety criteria.

Related Standards

• IEC 61558-1:2005 – General safety requirements for transformers, reactors, and power supply units; IEC 61558-2-5 is designed to be read in conjunction with this part.
• IEC 61558-2-16 – This part addresses switch mode power supply units, complementing IEC 61558-2-5 for higher frequency power supplies.
• IEC Guide 104:1997 – Provides guidance on preparation and use of group safety publications, under which IEC 61558-2-5 qualifies.

Manufacturers should also consider national and industry-specific standards when deploying transformers in vehicles, ships, or aircraft due to additional safety or environmental considerations.

Keywords: IEC 61558-2-5, shaver transformer safety, power supply safety, transformer testing, electrical transformer standards, shaver power supply units, IEC transformer standards, safety of electrical transformers, consumer appliance safety, dry-type transformers.