IEC 63522-10:2025

Overview

IEC 63522-10:2025 - Electrical relays: Tests and measurements - Part 10: Heating defines a standardized heating test method to assess the ability of relays (DUTs) to withstand temperatures encountered during transportation, storage and all aspects of operational use. The standard specifies test set‑up, energization and measurement techniques to determine temperature rise of coils, terminals and other relay parts under controlled conditions.

Key topics and technical requirements

• Test purpose: Determine that temperature rise of relay parts does not exceed specified limits.
• Test procedures:
  • Test A (Group mounting): three relays mounted side‑by‑side (see Annex A).
  • Test B (Single mounting): single relay tested.
• Mounting and orientation: Default horizontal position with terminals pointing downward; mounting distances declared by manufacturer.
• Coil energization: Typically the coil is energized at 1.1× rated coil voltage (or manufacturer‑specified limiting coil voltage). Special provisions for PWM or bistable coils and separate steps for make and break contacts.
• Temperature measurement:
  • Coil temperature by the resistance method using measured resistance change and the material constant (234.5 for electrolytic copper per IEC 60228). Manufacturers must specify alternative constants for other materials.
  • Other parts and terminals measured using fine‑wire thermocouples or equivalent sensors with negligible thermal influence.
• Heat chamber conditions: Sufficiently large chamber without forced convection; DUT protected from drafts and artificial cooling; ambient temperature held at room temperature or upper operating limit.
• Terminals and connections: Specific arrangements for solder terminals, flat quick‑connect terminations and screw/screwless terminals, including conductor types, minimum conductor lengths in chamber and use of nickel‑plated female connectors for quick‑connect tests.
• Assembly details: Terminal screws tightened to two‑thirds of torque specified in IEC 60998‑1 or IEC 60999‑1; correct fitting of conductors for screwless terminals.

Applications and who uses this standard

• Relay manufacturers for product design verification and type testing.
• Independent test laboratories and certification bodies performing relay heating/temperature‑rise tests.
• OEMs and systems integrators specifying reliable relays for industrial control, power distribution, automotive, railway and consumer applications.
• Quality, reliability and R&D engineers validating thermal performance during normal use, overloads or specific duty cycles.

Related standards

• IEC 63522‑0: General guidance and common test conditions for the 63522 series.
• IEC 60998‑1, IEC 60999‑1, IEC 60999‑2: Connecting device and terminal requirements referenced for torque, conductor sizing and terminal arrangements.
• IEC 61210: Flat quick‑connect termination requirements.

Keywords: IEC 63522-10:2025, electrical relays heating test, temperature rise, relay testing, thermocouples, resistance method, heat chamber, relay certification.