IEC 60885-3:2015

Overview

IEC 60885-3:2015 is an internationally recognized standard published by the International Electrotechnical Commission (IEC) that focuses on electrical test methods for electric cables, specifically detailing the procedures for partial discharge (PD) measurements on lengths of extruded power cables. The standard provides comprehensive methodologies to ascertain the presence and magnitude of partial discharges during testing, ensuring reliable quality and operational integrity of power cables before installation. Importantly, IEC 60885-3 applies to cable lengths in manufacturing and testing environments, but it does not cover measurements conducted on installed cable systems.

This second edition of IEC 60885-3 reflects advancements in test sensitivity assessment, updates measurement practices for partial discharge magnitude (now in picocoulombs), and revises the clause structure for clearer and more practical guidance in line with IEC's general numbering scheme.

Key Topics

• Partial Discharge Testing Principles

  • Emphasis on PD measurements based on methodologies outlined in IEC 60270.
  • Assessment of discharge magnitude at specific voltages and declared minimum sensitivity.
  • Handling of background noise and signal identification during PD detection.

• Classification of Cable Lengths

  • Distinction between short and long cable lengths for test setup.
  • Short cables are treated as lumped capacitors; longer cables exhibit transmission line behavior and require more advanced measurement techniques due to traveling PD pulses.

• Test Apparatus and Circuit Configuration

  • Requires calibrated high-voltage sources, coupling capacitors, PD measuring circuits, discharge calibrators, and oscilloscopes.
  • Use of terminal impedance and reflection suppressors to manage wave reflections in long cables-critical for accurate PD pulse measurement.

• Practical Assessment of Sensitivity

  • Sensitivity is now based on the minimum level of detectable discharge, replacing earlier definitions linked to background noise.
  • Calibration procedures ensure accuracy of PD measurements across varying cable lengths.

• Measurement Procedures

  • Clear instructions for conducting routine and type tests on different cable lengths.
  • Use of double pulse diagrams for characterization of long cable test conditions and identification of potential measurement errors due to pulse superposition and attenuation.

Applications

IEC 60885-3:2015 is relevant in numerous industrial and utility settings where extruded power cables are manufactured, tested, and certified before deployment. Key applications include:

• Quality Assurance in Manufacturing: Ensures that extruded power cables meet reliability and safety criteria through standardized partial discharge measurements.
• Type and Routine Testing: Facilitates both prototype (type) and production-based (routine) verification of cable insulation performance.
• Research and Development: Provides a repeatable framework for evaluating new cable materials and designs under controlled laboratory conditions.
• Conformance and Procurement: Used by manufacturers and buyers to specify and verify conformity with international PD test requirements, reducing risk of premature cable failure.

Related Standards

To ensure comprehensive and compliant PD testing, IEC 60885-3:2015 references and relates closely to the following standards:

• IEC 60270 - High-voltage test techniques – Partial discharge measurements: The foundational document for general PD measurement methodologies.
• Other IEC 60885 Series Standards - Provide further electrical test methods for electric cables, such as mechanical and thermal testing provisions.

By adhering to IEC 60885-3:2015, stakeholders in the power cable industry can achieve robust quality management during cable production, enhance safety, and ensure alignment with international best practices for high-voltage testing and partial discharge measurement.