Purged & pressurized motors made to IEC / NEC / CEC Zone 1 (EX P) & to NEC/CEC Division 1 (type X): Are they the same?

Electric motors have been used in Zone 1 and Division 1 hazardous areas for many years. These motors operate in hazardous (classified) locations where an explosive gas or vapor atmosphere is likely to be present in a normal operation. Motors operating in this area require special protection against igniting the explosive gas or vapor. In order to operate these motors safely, special protection such as purged and pressurization or explosion proof enclosure is required. The large fabricated frame motors are typically protected by the purged and pressurized technique. Zone 1 or Division 1 hazardous (Classified) locations have been defined to be essentially the same in NFPA 70, National Electrical Code (NEC), C22.1, Canadian Electric Code (CEC) and International standards (IEC). The petroleum and chemical facility environments for IEC/NEC/CEC Zone 1 and NEC/CEC Division 1 are not different, yet the safety requirements and how the motors are used in these areas are addressed from competing vantage points. The codes and standards are transcending national barriers in an attempt to synchronize without sacrificing safety requirements, however, there are still diverging regulations. These diverging requirements are discussed below.