Questions and Answers
An atmosphere that contains a volatile gas during normal operation of the equipment would be considered a _____________ location.
class 1 division 1
The space in the immediate vicinity inside of the motor dispensing unit at an automotive service station is identified as a?
class 1 division 1 location
How would a cabinet manufacturer classify areas for woodworking and application of the final finishes?
class 1 for the finishing areas and class 3 for the woodworking areas
What is the classification of all floor level areas up to a height of 18 inches in an airport hangar?
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An atmosphere that normally contains gasoline vapor would fall into which group?
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Class 1 division 1 location is best described as an atmosphere that?
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Which of the following locations requires the use of a totally enclosed generator?
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Rigid metal conduit is acceptable in class 1 division 1 environment.
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Which of the following locations are hazardous due to the presence of combustible dust?
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In general, when are seals typically installed?
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All of the following are potential ignition sources, except __________.
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One way to prevent explosions is to reduce the concentration of the explosive vapor using appropriate ventilation.
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Equipment that is incapable of releasing sufficient electrical energy to cause ignition of a hazardous atmospheric mixture is considered?
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The main purpose of the seals in conduit runs is to __________.
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Class 1 division 1 group C can be used for?
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In hazardous locations where threaded metal conduit is required, how many threads must be fully engaged?
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Significant moisture can collect in a conduit system, even if it is not installed in a wet or damp location.
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Which of the following is approved for use in most class 1 division 1 locations?
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In class 2 locations where the raceway communicates with a dust ignition proof enclosure, the vertical raceway must be at least ______ feet long.
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All sealing compounds can be used in all applications.
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Which of the following covers intrinsically safe equipment?
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Which device helps prevent moisture from collecting in a raceway system?
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All conduit systems running beneath hazardous locations are not considered hazardous as long as they are embedded in concrete.
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Grounding is not required for the metal noncurrent carrying parts of gasoline dispensers.
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The requirement for electrical equipment and wiring for all voltages in locations where fire or explosion hazards may exist are covered in _______.
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When you are standing at a pump dispensing gasoline, you are located in a _____________ area.
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A partitioned (open ceiling) storage area in an airplane hangar is considered a?
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The NEC only contains requirements for equipment located within 5 feet above an airplane engine.
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The NEC requirement for essential electrical systems in hospitals are covered in _____________.
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Installations in petrochemical facilities are regulated by?
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Study Notes
Hazardous Location Classifications
- Class 1 Division 1 indicates atmospheres with volatile gases that are normally present.
- Class 1 Division 1 locations include the immediate vicinity of automotive service station motor dispensing units.
- Class 1 locations are for areas where ignitable gases are present, while Class 3 is designated for areas with non-conductive materials like woodworking.
Specific Classifications and Groups
- Airport hangar floor areas up to 18 inches in height are classified as Class 1 Division 2.
- Atmospheres containing gasoline vapor are classified under Group D.
- Class 1 Division 1 pertains to environments that are typically hazardous.
Equipment and Installation Requirements
- Totally enclosed generators are required in Class 1, Class 2, and Class 3 locations.
- Rigid metal conduit is suitable for use in Class 1 Division 1 environments.
- Threaded joints in threaded metal conduit must have at least five threads fully engaged.
Safety and Prevention Measures
- To prevent explosions, reducing explosive vapor concentration through ventilation is effective.
- Any ignition sources, except for portable aluminum tools, can pose a risk in hazardous locations.
- Seals in conduit runs prevent the passage of gases, vapors, or flames between sections.
Intrinsically Safe Equipment
- Equipment classified as intrinsically safe cannot produce enough electrical energy to ignite hazardous atmospheres.
- The requirements for intrinsically safe equipment are outlined in NEC Article 504.
Conduit Systems and Moisture Management
- Significant moisture can accumulate in conduit systems, even those not directly in wet or damp locations.
- An integral drain is used to prevent moisture buildup in raceway systems.
Regulatory Framework
- NEC Articles 500 to 504 cover electrical equipment and wiring in fire or explosion hazard areas.
- Regulatory oversight for installations in petrochemical facilities comes from local agencies and the NEC.
Miscellaneous
- Class 1 Division 2 locations include areas such as gas pumps and partitioned storage areas in hangars.
- Essential electrical systems in hospitals are under NEC Article 517, part 3.
- Conduit systems embedded in concrete are still considered hazardous if they run beneath hazardous locations.
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Test your knowledge of hazardous locations with these flashcards. Each card presents an important term related to classification and safety in environments with volatile gases. Perfect for professionals in safety and equipment handling fields.
