Hazloc - Explosion Protection in North America
Unlike in many other parts of the world, the explosion protection in the US is not based on IEC specifications.
With a similarly high safety level, this results in specific technical solutions as well as a separate categorisation of technical devices with regard to the corresponding explosive environment and the explosive mixture.
Safety Standard NEC
The specifications for electrical equipment originate from the NEC The National Electrical Code (NEC) is a safety standard of the United States of America. This formulates the specifications for the design of electrical installations.
HazLoc
Unlike e.g. in Europe, devices are not categorised according to their use, but rather into "Classes" and "Divisions". In the USA the term "Hazloc" is used in a similar manner to "ATEX" in Europe.
Scope of Application
USA (and Canada for existing plants)
Basis
USA: NEC National Electrical Code (Canada: CEC Canadian Electrical Code)
In 1996, the IEC classification system (categorisation according to zones) was also introduced for Class I. This change was made by Article 505 of the NEC, which gives the user the opportunity to choose the system that is technically and economically optimal for their purposes. In 2005, Zones 20, 21, and 22 for areas with flammable dust (Article 506) were introduced.
NEC - National Electrical Code
- 500: General requirements for Class I, II and III Divisions
- 501: Requirements for Class I Divisions
- 502: Requirements for Class II Divisions
- 503: Requirements for Class III Divisions
- 504: Requirements for Class I, II and III Divisions with regard to intrinsic safety (IS)
- 505: General and specific requirements for Zone 0, 1, and 2
- 506: General and specific requirements for Zone 20, 21, and 22