THE NET EFFECT - A DETAILED IMPACT ANALYSIS OF A 3-LEVEL CLASSIFICATION-SYSTEM ON THE ELECTRICAL-INDUSTRY

The 1993 National Electrical Code (NEC) cycle contained a very controv ersial proposal-a proposal to change the area classification system fo r Class I hazardous (classified) locations from a two-division system to a three-division system, In general, the ''user'' representatives o n Code Making Panel 14 supported this change, but the other representa tives did not, Similarly, in 1987, a number of Western Canadian users and consultants began to develop a real awareness of the International Electrotechnical Commission (TEC) System for classified locations. Si nce that time, this group of Canadians has spent significant time rese arching the IEC System. They have developed and implemented a plan to make the necessary changes to the Canadian electrical installation cod es and standards to allow Canadian users access to IEC technology. The change to permit use of the international classification system in No rth America has been controversial-to say the least. The authors' appr oach to this paper was to assume that both the North American and the IEC systems for classified locations have been proven to be safe. The paper disregards the unsubstantiated claims and counter-claims made by those on both sides of the issue. Clearly, there are differences betw een the two systems, and this paper explores these differences. The pa per attempts to emphasize the differences between the two systems to a llow the readers to draw their own conclusions as to which system is b est for their applications. A comparison is made between a typical Nor th American installation and a typical IEC installation to illustrate the impact of change to a three-division system.