Conductor Failure Investigation

Comprehensive Services for Investigative Testing and Failue Analysis

Project Objective

An electric utility in North America experienced a catastrophic conductor failure. To prevent future costly failure events, the utility wanted to better understand what caused this failure. Was it caused by a manufacturing defect, an installation issue, anatural weather event?  To answer these questions, Kinectrics performed a series of investigative tests on the utility’s conductor after the failure event. Several lengths of conductor, designated as Aluminum Conductor Steel Reinforced (ACSR), were harvested from the location of the failure and sent to Kinectrics for testing.

The purpose of the testing was to determine the extent of conductor degradation that may have occurred due to in-service conditions such as vibration, ice loading etc. and, attempt to identify the potential root cause of the conductor failure.   

Scope of Work

Several routine tests were performed on the individual aluminum and galvanized steel wires to assess the actual condition of the harvested conductor samples. Testing incorporated “Kinectrics’ Methodology” that has been developed to assess aged conductor samples. The program included several tests chosen to maximize the information obtained from the harvested sample.  

1) Six (6) Routine Conductor Assessment Tests on Individual Wires:

    • Torsional Ductility
    • Tension and Elongation
    • Visual Examination
    • Remaining Zinc on Galvanized Steel Wires
    • Wrap Test
    • DC Resistance / Resistivity Test

2)  DC Resistance of Complete Conductor

3)  Tensile Breaking Strength of Complete ConductorTensile Breaking Strength of Complete Conductor

4)  Metallurgical Analysis of Failed Conductor Ends

Results

Based on the laboratory testing and metallurgical analysis of the harvested ACSR conductor samples, the conductor failure was attributed to a tensile overload.  There were no signs of significant deterioration or degradation from in-service conditions that may have led to a premature failure.  Although there were signs of general wear and fatigue on the aluminum wires, there was no evidence to link the signs of wear directly to the conductor failures. 

In addition, a number of steps were recommended to assist in the development of practical tools to perform and expedite failure investigations. 
 

Client Benefits

A comprehensive in-depth analysis of the conductor harvested from the location of the failure was delivered to the client.  By understanding the extent of actual damage and failure mode, the utility can now make more informed confident decisions related to their assets. These informed decisions may lead to substantial cost savings for the client by reducing unnecessary or inadequate repairs / maintenance on their ageing infrastructure. 

 

 

 

 

About This Case Study

Industry Sector

  • Transmission & Distribution

Generation Type

  • Renewable

Nature of Service

  • Analysis
  • |
  • Inspection
  • |
  • Testing - Lab Services

Client Assets

  • Conductors

Kinetrics Facilities

  • Mechanical Equipment Testing Facilities

Tags

  • wrap test
  • |
  • metallurigal analysis
  • |
  • ACSR
  • |
  • conductor failure analysis
  • |
  • failure investigation
  • |
  • tensile strength