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Areas that need Explosion Proof Protection |
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Grain Elevators |
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Oil Refineries |
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Coker Plants |
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Pharmaceutical Plants, |
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Gas Utility Facilities |
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Water Treatment Plants |
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Flour and Feed Mills |
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Passenger & Freight Elevators |
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Coal Preparation Plants |
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Mines |
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Starch, Aluminum, Sulfur, Propane, Magnesium, etc. Processing Plants |
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The listed locations above are just a few of the many that require explosion proof protection. |
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The Complete Elevator System |
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When determining what requires explosion proof protection make sure all the parts of the elevator are covered. |
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UT Offers the following for your hazardous location protection needs: |
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Machine Room |
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- Elevator Control System
- Machine Room Lighting
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Top of Hoist way |
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- Final, Normal & Slow Down Switches
- Access Over Travel Limit Switch
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Inside Elevator |
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- Main & Auxiliary Car Station – for both Passenger and Freight applications
- Car Position Indicators – Digital / Multilight
- Traveling Lanterns – Vandal Proof
- Cab Lighting
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Outside Mounted on Elevator |
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Car Top Inspection Station 2/Worklight & Receptacle |
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Elevator Entrance / Hallway |
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- Hall Station – Loaded with Features
- Multi Light Position Indicators
- Hall Lanterns
- Access Switch Stations
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Elevator Pit / Bottom of Hoist way |
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- Final, Normal & Slow Down Switches
- Pit Switch
- Pit Work light and GFCI Receptacle
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DEFINING HAZARDOUS LOCATIONS |
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Hazardous Location Classifications Elevator Equipment |
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The following is an overview of hazardous location classifications as they apply to elevator equipment. This is intended to give elevator sales, technical and field personnel a better understanding of the hazardous location designations and the equipment available to meet these requirements. The actual processes employed to define and assign hazardous location designations are complex and beyond the scope of this summary |
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General |
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Hazardous location elevator equipment is necessary in any area where the possibility of fire or explosion exists, or may exist because of flammable gases or vapors, flammable liquids, combustible dust, or ignitable fibers. These types of dangers are officially classified by location (Class, Division and Group) depending on the properties of the flammable vapors, liquids or gases, combustible dusts or fibers that may be present and/ or the likelihood that a flammable or combustible concentration or quantity is present. |
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Class I Area Classification |
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Area in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures are Class-I |
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Group A, B, C & D – Defines the type of combustible gases in the Class I location atmosphere. |
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Class I Area Group: |
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Division 1 and 2 |
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A (Acetylene)
B (Hydrogen)
C (Ethylene)
D (Propane) |
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Class II Area Classification |
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Area where combustible metal, carbonaceous dust, or other combustible dust such as flour, grain, wood, etc., are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures are Class II. |
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Group E, F & G – Defines the type of combustible dust in the Class II location atmosphere. |
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Class II Area Groups |
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Division 1 and 2 |
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E (Metals – Divn.1 only)
F (Coal)
G (Grain) |
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Class III Area Classification |
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Areas that are hazardous because of the presence of easily ignitable fibers or flyings, but are not likely to be in suspension in the air in quantities sufficient to produce ignitable mixtures are Class III. |
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Class III Groups |
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Division 1 and 2 |
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None |
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Division 1 Area Classification |
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A Division I location is one in which the ignitable or combustible gases, vapors or dust can exist under normal operating conditions. |
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Division 2 Area Classification |
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A Division 2 location is one in which the ignitable or combustible gases, vapors or dust are stores, handled, processed or used, but normally confined within closed containers or systems, or dispersed by positive mechanical ventilation. In this division the hazard is created by accidental rupture of containers or systems, or equipment failure. |
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NEMA Classifications |
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Hazardous location enclosures are rated based on the Class and Group to which they will be installed. These are: |
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NEMA 7- |
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Enclosures for use in locations classified as Class 1, Groups A, B, C or D. (Combustible gases). |
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NEMA 9- |
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Enclosures for use in locations classified as Class II, Groups E, F, or G. (Combustible dust). |
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NEMA 4X - |
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Enclosures for use in Class 1, Division 2 locations if used in conjunction with hermetically sealed contacts. Water / Corrosion Resistant Enclosures are constructed to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water and corrosion |
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Summary & Recommendations |
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To summarize these hazardous location classifications for elevator applications: (1) the Class and Group designation specifies if the exposure is gaseous or combustible dust and (2) the Division specifies if the hazard is always present or exists only when a problem occurs. |
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IN Class I or II, division 2 areas exceptions to the enclosure rating are allowed. For elevator applications in Division 2, general purpose enclosures are permissible if used in conjunction with hermetically sealed contacts. For maximum protection the general purpose enclosure should be NEMA-4X rated. |
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