IEC 63522-20:2025

Overview

IEC 63522-20:2025 is an internationally recognized standard from the International Electrotechnical Commission (IEC) that defines the test methods for assessing the mechanical endurance of electrical relays. This part of the IEC 63522 series focuses specifically on ensuring that relays can withstand the mechanical stresses they encounter during transportation, storage, and operation over an extended number of cycles. The standard provides a uniform approach for manufacturers and testing laboratories to evaluate the mechanical durability of relays, which is crucial for reliability and safety in various electrical and electronic applications.

Key Topics

• Scope and Application: This standard applies to testing relays under mechanical endurance conditions, independent of electrical endurance, though electrical endurance can be considered a subset of mechanical endurance testing.

• Test Procedures:

  • Relays are energized with the rated coil voltage or an appropriate rated value at ambient room temperature unless otherwise specified.
  • Two primary methods are defined for monitoring mechanical endurance:
    • Method 1: Continuous Checking - Continuous electrical monitoring using contact loads or alternative methods such as coil current curves or sensors.
    • Method 2: Intermediate Checking - Periodic inspections and measurements at specified intervals, usually every 20% of the endurance cycle count.
  • Contact load should be chosen within CC0 or CC1 categories to reliably detect relay operations without causing undue wear.

• Conditions to Specify: Various critical parameters must be documented, including:

  • Test method chosen (continuous or intermediate checking)
  • Mounting and ambient conditions
  • Energization voltage and frequency of operation
  • Number of cycles and duration
  • Contact configuration and monitoring details
  • Allowable malfunction thresholds

• Evaluation and Acceptance Criteria:

  • Malfunctions during the test must not exceed 0.1% of total cycles in continuous monitoring.
  • Intermediate measurements must comply with criteria defined in IEC 63522-6 and IEC 63522-7.
  • A post-test visual inspection verifies mechanical integrity, with failure indicated by any loose or broken critical or safety-related components.
  • A comprehensive test report should be produced following the prescribed format.

Applications

The IEC 63522-20:2025 standard is essential for industries and sectors relying on the consistent mechanical performance of electrical relays, including:

• Power Systems: Protection and control relays in power distribution and transmission networks must maintain performance after extensive mechanical cycling.
• Industrial Automation: Machinery safety and control depend on relays that endure harsh working environments.
• Transportation Equipment: Relays used in transportation systems must resist mechanical stresses from vibration and handling.
• Consumer and Commercial Electronics: Ensures reliability in devices subject to frequent switching operations.
• Relay Manufacturing and Quality Control: Enables manufacturers to validate mechanical endurance under internationally agreed testing conditions, facilitating market access and compliance with global client requirements.

Related Standards

IEC 63522-20:2025 is part of the broader IEC 63522 series on Electrical relays – Tests and measurements, which includes complementary parts addressing:

• IEC 63522-0 (under preparation): General testing principles and guidance for electrical relay tests.
• IEC 63522-6: Contact-circuit resistance (or voltage drop) tests - relevant for intermediate evaluations during mechanical endurance testing.
• IEC 63522-7 (under preparation): Functional tests ensuring relays meet operational criteria.
• IEC 63522-45: Specifies maximum frequency of operation, important for defining test cycle frequencies during mechanical endurance tests.

Together, these standards deliver comprehensive methods for assessing electrical relay performance under mechanical, electrical, and operational conditions, establishing a globally harmonized framework for relay testing.

By applying IEC 63522-20:2025, organizations can ensure that their electrical relays exhibit high mechanical endurance, leading to enhanced reliability and safety in electrical systems worldwide. This contributes to reducing failures and maintenance costs while complying with international quality expectations.