Preface 

This is the second edition of CSA C310, Distribution class polymeric cutouts. This Standard addresses the electrical and mechanical characteristics of cutouts made from polymeric materials. Annex A contains commentary on some of the clauses of this Standard. Funding in support of the consensus process of this Standard was provided by the following funders, whose assistance is acknowledged with thanks: Canadian Electricity Association (CEA), Schneider Electric Canada Inc., IFD Corporation, Hydro Quebec, S&C Electric Canada Ltd., Fortis Alberta, Fortis BC, Maritime Electric, Newfoundland Hydro, Newfoundland Power, EPCOR, Utilities Standards Forum (USF), Alectra Utilities, and Hydro One. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. 

Scope 

1.1 This Standard applies to open-type (fused and solid-blade) cutouts with a polymeric insulator structure component. These cutouts are intended for operation on alternating current distribution systems. 

1.2 In some cases, specific types of construction are envisaged. This does not preclude the use of other types of construction, provided that the engineering representatives involved can demonstrate the safety and suitability of these alternatives. 

1.3 In this Standard, "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 (non-mandatory) to define their application. 

1.4 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.