Oxygen Analyzer Enclosure Types
Oxygen analyzers can be purchased in one of several NEMA (National Electrical Manufacturers Association) rated enclosures. The following is a review of these enclosures along with a brief description. Please refer to the references at the bottom of this section for more detailed information on non-hazardous and hazardous enclosures.
NON-HAZARDOUS ENCLOSURE TYPES
Type 1 Enclosures: Oxygen analyzers with Type 1 enclosures are intended for indoor use primarily to provide protection against contact with the enclosed equipment in locations where unusual service conditions do not exist.
Type 2 Enclosures: Oxygen analyzers with Type 2 enclosures are intended for indoor use primarily to provide a degree of protection against limited amounts of falling water and dirt. They are not intended to provide protection against conditions such as dust or internal condensation.
Type 3R Enclosures: Oxygen analyzers with Type 3R enclosures are intended for outdoor use primarily to provide a degree of protection against falling rain, sleet, and external ice formation. They are not intended to provide protection against conditions such as dirt, internal condensation, or internal icing.
Type 3 Enclosures: Oxygen analyzers with Type 3 enclosures are intended for outdoor use primarily to provide a degree of protection against wind blown dust, rain, sleet, and external ice formation. They are not intended to provide protection against conditions such as internal condensation or internal icing.
Type 4 Enclosures: Oxygen analyzers with Type 4 enclosures are designed for indoor or outdoor use primarily to provide a degree of protection against windblown dust and rain, splashing water, and hose-directed water. They are not intended to provide protection against conditions such as internal condensation or internal icing.
Type 5 Enclosures: Oxygen analyzers with Type 5 enclosures are designed for indoor use primarily to provide a degree of protection against dust and falling dirt. They are not intended to provide protection conditions such as internal icing.
Type 6 Enclosures: Oxygen analyzers with Type 6 enclosures are intended for indoor or outdoor use primarily to provide a degree of protection against the entry of water during occasional temporary submersion at a limited depth. They are not intended to provide protection against conditions such as internal condensation, internal icing, or corrosive environments.
Type 11 Enclosures: Type 11 enclosures are intended for indoor use primarily to provide, by oil immersion, a degree of protection to enclosed equipment against the corrosive effects of liquids and gases. They are not intended to provide protection against conditions such as internal condensation or internal icing.
Type 12 Enclosures: Oxygen analyzers with Type 12 enclosures are intended for indoor use primarily to provide a degree of protection against dust, falling dirt, and dripping water. They are not intended to provide protection against conditions such as internal condensation.
Type 13 Enclosures: Oxygen analyzers with Type 13 enclosures are intended for indoor use primarily to provide a degree of protection against dust, spraying of water, oil, and non-corrosive coolant. They are not intended to provide protection against conditions such as internal condensation. Back To Top
HAZARDOUS ENCLOSURE TYPES
Type 7 Enclosure: Oxygen analyzers with Type 7 enclosures are for indoor use in locations classified as Class 1, Groups A, B, C, or D as defined in the National Electrical Code. Oxygen analyzers equipped with Type 7 enclosures shall be capable of withstanding the pressures resulting from an internal explosion of specified gases, and contain such an explosion sufficiently that an explosive gas-air mixture existing in the atmosphere surrounding the enclosure will not be ignited. Enclosed heat generating devices shall not cause external surfaces to reach temperatures capable of igniting explosive gas air mixtures in the surrounding atmosphere. Enclosures shall meet explosion, hydrostatic, and temperature design tests.
Type 8 Enclosure: Oxygen analyzers with Type 8 enclosures are for indoor or outdoor use in locations classified as Class 1, Groups A, B, C, or D as defined in the National Electrical Code. Oxygen analyzers equipped with Type 8 enclosures and enclosed devices are arranged such that all arcing contacts, connections, etc, are immersed in oil. Arcing is confined under the oil such that is will not ignite and explosive mixture of the specified gases in internal spaces above the oil or in the atmosphere surrounding the enclosure. Enclosed heat generating devices shall not cause external surfaces to reach temperatures capable of igniting explosive gas-air mixtures in the surrounding atmosphere. Enclosures shall meet operation and temperature design tests. Enclosures intended for outdoor use shall also meet rain tests.
Type 9 Enclosure: Oxygen analyzers with a Type 9 enclosure are intended for indoor use in locations classified as Class II, Groups E, F, or G, as defined in the National Electrical Code. Type 9 enclosures shall be capable of preventing entrance of dust. Enclosed heat generating devices shall not cause external surfaces to reach temperatures capable of igniting or discoloring accumulated dust on the enclosure or igniting dust-air mixtures in the surrounding atmosphere. Enclosures shall meet dust penetration and temperature design tests and aging of gaskets (if used).
For much more details on the aforementioned enclosure types, the following web site should be viewed:
- National Electrical Manufacturers Association: http://www.nema.org/
- Further information on hazardous area classification can be obtained byordering the book entitled, “ Understanding Hazardous Area Sensing” by
Bob Svacina & Brad Larson at TURCK Inc., Tel: 612.553.7300
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