The Canadian electrical code for hazardous locations has no class — But it does have significant changes

The 2015 Edition of the Canadian Electrical Code (CEC) [1] is taking one step closer to the rest of the world and one step further from the US National Electrical Code (NEC) [2]. For decades, both the CEC and NEC have used the term "Class" to identify the various types of hazardous materials. The 23rd edition of the CEC has removed the term "Class" from Section 18 and replaced it with the International Electrotechnical Commission (IEC) Zone system. Class I, which was changed in 1998 to include Zones, becomes simply Zones 0, 1 and 2. Class II and Class III were merged to become Zones 20, 21 and 22. Figure I shows the introduction of hazardous location requirements into the CEC. All new construction must use the new system for area classification. The legacy "Class" and "Division" system was relocated to Appendix J. The CEC does allow for continued use of the Class/Division System in existing facilities. However, all new facilities must use the Zone System for all Explosive Atmosphere s. This change does not prevent the use of Class/Division equipment in the Zone System. Tables were added that identify the types of Class/Division electrical equipment that can be used in the various Zones designated locations. The CEC approach differs considerably from the NEC. Although the NEC contains a variation of the IEC full system in Article 505 and Article 506, it permits the user to select either the Class/Division or Class/Zone system. This paper will explain the changes to the CEC and highlights the differences between it, the IEC system and the NEC.