Evaluation methods for arc resistance ratings of enclosed electrical equipment

1.1
This Standard establishes methods by which metal-enclosed equipment can be tested for resistance to the effects of arcing resulting from an internal fault.

1.2
This Standard applies only to indoor and outdoor equipment that uses air as the primary insulating medium and that is rated up to 46 kV ac.

Note: Building size and construction are factors to be considered in indoor applications. These factors are not addressed in this Standard.

1.3
The tests and assessments described in this Standard are applicable only to arcing faults occurring entirely in air within the enclosure when all doors and covers are properly secured.

1.4
This Standard does not apply to arcing faults that occur within a component of the assembly, such as instrument transformers, sealed interrupting devices, or fuses.

1.5
Metal-enclosed switchgear designs that meet the requirements of this Standard are referred to as arc-resistant switchgear. Motor control designs that meet the requirements of this Standard are referred to as arc-resistant motor control.

Note: Annex C provides additional information on the consequences of internal arc faults, equipment qualified to this Standard, relevance of tests, and the application of this Standard.

1.6
In CSA Standards, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (nonmandatory) to define their application.

1.7
The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.