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8735014 
Meetings & Symposia 
Electrical process seal requirements in north american electrical codes 
Driscoll, T; Cole, M; Leduc, R 
2008 
English 
Both the National Electrical Code (NEC) [1] and the Canadian Electrical Code (CEC) [2] contain sealing requirements to prevent the migration of flammable fluids from travelling through wiring systems to non-hazardous locations. This paper will review the need for, the intent and the application of these code requirements. Case studies of incidents will be discussed to demonstrate that significant hazards exist, and how they are effectively mitigated by the code requirements. In addition, product standards can be used to meet the intent of the sealing requirements. CSA C22.2 No. 30 Explosion Proof Enclosures for use in Class I Hazardous Locations [3], and ANSI/ISA 12.27.01 Requirements for Process Sealing Between Electrical Systems and Flammable or Combustible Process Fluids [4] currently exist and IEEE PAR 1673 Requirements for Conduit and Cable Seals for Field Connected Wiring to Equipment in Petroleum and Chemical Industry Exposed to Pressures Above 1.5 kilopascals (0.22 psi) [5] is under development. In Canada, the new rules on process sealing have created a situation where process industries must transition to meeting these requirements with little knowledge or direction. In Alberta, where there is a massive amount of investment in process industries, the Provincial Regulator in collaboration with Industry, including Certification Bodies and CEC Section 18 (Hazardous Locations) representation, has: •Clarified what the new requirements mean, specifically on "secondary seals" and "making primary seal leaking obvious", •Provided background information to help answer the question: "Why are these rules needed?", and •Given manufacturers (e.g., process transmitters) a path forward to have their products certified (listed) to appropriate standards. This Alberta initiative has prompted many manufacturers to pursue certification (listing) of products and is expected to impact future changes to the code requirements and to IEEE 1673. 
Conduit; Dual seal device; Explosive fluid); Primary; Process; Process fluid; Process-connected equipment; Seal (Cable; Secondary; Single seal device