Overview
IEC TS 60695-2-21:2023 is a Technical Specification from the IEC that defines a fire containment test for finished electrical units using glowing/hot-wire based methods. The method simulates an internal ignition source (overheated electrical connections) and verifies whether a finished unit can contain a fire initiated inside it. This document is part of the IEC 60695 series on fire hazard testing and is intended for manufacturers, test labs and standards writers concerned with electrical safety and fire resistance of finished products.
Key Topics and Requirements
- Scope and applicability
- Applies to finished units (not to single electrical components or many electrical installation products such as distribution boards, switchgear, circuit protection devices and wiring devices), unless a product standard states otherwise.
- Test specimen preparation
- Guidance on specimen selection, conditioning and identification of potential ignition sources inside the unit.
- Test apparatus
- Specification of essential equipment and consumables including NiCr (nickel-chromium) wire, test circuit, connections, cheesecloth, test chamber and timing devices.
- NiCr wire verification and application
- Methods to verify and position the glowing/hot-wire ignition source (internal coil winding, external winding and other application techniques are covered in normative annexes).
- Test procedure
- Stepwise test flow chart, pre-test verification of ignition potential, test conditions and observation points.
- Observations, measurements and evaluation
- What to record during and after the test, pass/fail criteria and how to report results.
- Documentation
- Requirements for the test report and information that should be specified in relevant product standards.
- Annexes
- Normative annexes provide detailed application methods (coil winding, external winding), fixation techniques and illustrative figures.
Applications and Who Uses It
- Product designers and manufacturers of finished electrical/electronic units use this TS to evaluate and improve design resilience against internal ignition sources.
- Independent testing laboratories apply the method to verify fire containment claims during type testing and certification activities.
- Standards developers and regulatory bodies reference the specification when defining product-specific fire containment requirements.
- Practical use-cases include assessing whether internal wiring, connectors or insulating cavities could lead to an internal fire that escapes the enclosure and causes a larger hazard.
Related Standards
- Part of the IEC 60695 Fire hazard testing series (see other parts for glow wire, flammability and effluent tests).
- Product-specific standards may reference IEC TS 60695-2-21 for finished-unit fire containment requirements - check the relevant product standard for mandatory applicability.
Keywords: IEC TS 60695-2-21, fire containment test, glowing/hot-wire, finished units, NiCr wire, fire hazard testing, electrical safety, IEC 60695.