Zones versus divisions: a comparative analysis of NEC articles 500 and 505 equipment and wiring methods in a petrochemical facility in the united states

Codes and standards now exist which allow petrochemical facilities in the United States to be classified using the Zone method of area classification. Owners, operators and designers of these facilities now have options in choosing the method of area classification and in selecting the type of equipment protection techniques and wiring methods employed. This panel discusses the results of a detailed comparison made of Division-and Zone-based wiring systems for an onshore oil and. gas production facility in the United States. Issues considered include equipment cost and availability, installation costs and maintenance and safety considerations. Conclusions and recommendations are made on a life-of-facility cost basis.