LIVE WORKING – MINIMUM APPROACH DISTANCES – Part 2: Method of determination of the electrical component distance for AC systems from 1,0 kV to 72,5 kV

Designation Number:
CAN/ULC-61472-2
Standard Type:
National Standard of Canada - Adoption of International Standard
Standard Development Activity:
New Standard
ICS code(s):
13.260; 29.240.99; 29.260.99
Status:
Proceeding to development
SDO Comment Period Start Date:
SDO Comment Period End Date:
Posted On:

Scope:

This part of IEC 61472 specifies a method for determining the electrical component of the minimum approach distances for live working, for AC systems 1 kV up to and including 72,5 kV. This document addresses system overvoltages and the working air distances between equipment and/or workers at different potentials.

The withstand voltage and minimum approach distances determined by the method described in this document can be used only if the following working conditions prevail:

  • workers are trained for, and skilled in, working live lines or close to live conductors or equipment;
  • the operating conditions are adjusted so that the statistical overvoltage does not exceed the value selected for the determination of the required withstand voltage;
  • transient overvoltages are the determining overvoltages;
  • tool insulation has no continuous film of moisture present on the surface;
  • no lightning is observed within 10 km of the work site;
  • allowance is made for the effect of the conducting components of tools.

NOTE In some countries, special procedures have been developed to permit live working with surface moisture on tools at distribution voltages (below 50 kV).

Project need:

The development of IEC 61472-2 and its adoption as a National Standard of Canada addresses the need to give a method to determine distances for minimal approach distances for voltages between 1 kV up to and including 72,5 kV.

Note: The information provided above was obtained by the Standards Council of Canada (SCC) and is provided as part of a centralized, transparent notification system for new standards development. The system allows SCC-accredited Standards Development Organizations (SDOs), and members of the public, to be informed of new work in Canadian standards development, and allows SCC-accredited SDOs to identify and resolve potential duplication of standards and effort.

Individual SDOs are responsible for the content and accuracy of the information presented here. The text is presented in the language in which it was provided to SCC.