Significance and Use
5.1 This test method is intended for determining the heat attenuation factor (HAF) of a shield material and the effective heat attenuation factor (EHAF) at the location of the worker. This can be obtained by measuring the reduction of the arc incident energy levels caused by a shield attached on a live line tool (hot stick) or on a racking rod and designed for protection for workers exposed to electric arcs. The shield mechanical strength (SMS) can be obtained from visual observations of the high speed video recordings of each shot during HAF tests.
5.1.1 Because of the variability of the arc exposure, different heat transmission values and pressure may result for individual sensors. The results of each sensor are evaluated in accordance with Section 12.
5.2 This test method maintains the shield and the heat sensors in a static, vertical position and does not involve movement except that resulting from the exposure.
5.3 This test method specifies a standard set of exposure conditions. Different exposure conditions may produce different results.
NOTE 1: In addition to the standard set of exposure conditions, other conditions representative of the expected hazard may be used and shall be reported should this data be cited.
Scope
1.1 This test method is used to determine the heat attenuation factor (HAF), the effective heat attenuation factor (EHAF), and the shields mechanical strength (SMS) of a shield attached on live line tools or racking rods intended for protection of workers exposed to electric arcs.
1.2 The materials used in this test method of worker protection are in the form of a shield attached on live line tools or on the racking rods.
1.3 The protective shield described in this test method shall be transparent and shall be easily attached and removed from live line tools or from racking rods.
1.4 The protective shield described in this test method has 24-in. (0.61-m) diameter and can be used for most applications, however for special cases, the shield can have different sizes to suit the protective requirements of the application.
1.5 This standard shall be used to measure and describe the properties of materials, products, or assemblies in response to incident energies (thermal-convective, and radiant and pressure wave) generated by an electric arc under controlled laboratory conditions and does not purport to predict damage from light, resultant pressure impact other than the pressure and thermal aspects measured.
1.6 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.7 This standard shall not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire assessment, which takes into account all of the factors, which are pertinent to an assessment of the fire hazard of a particular end use.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.For specific precautions, see Section 7.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.