Changes in hazardous locations requirements in the 1993 National Electrical Code

The National Electrical Code revision process is discussed, as are many of the proposals incorporated into the 1993 NEC. Nonincendive circuits are contrasted with nonincendive components. Resistivity is no longer used in classifying dusts, and coal is now considered nonconductive. Class II surface temperatures may now be based on the specific dust, not only the group involved. Proposals for Division 0 were rejected and this issue, including 'increased safety' is examined in detail. Type AC cable is excluded as a wiring method in hazardous locations. In Class I, a new method for sealing multiconductor cable in conduit is approved, as are additional types of cable tray in Cable II, Division 2.<
>