Exam 15: Hazardous Classified Locations

Areas in a garage adjacent to classified locations in which flammable vapor release is unlikely (such as a storeroom) shall be unclassified where ____.

Class III locations are hazardous because of the presence of ____, or where materials producing combustible flyings are handled, manufactured, or used, even though they are not likely to be airborne in quantities sufficient to produce ignitable mixtures.

Askarel-containing transformers rated in excess of 25 kVA shall have ____.

Type PVC conduit, Type RTRC conduit, and Type HDPE conduit can be used when first surrounded by at least ____ of concrete, followed by a minimum cover of 24 in.(600 mm) (top of conduit to grade).

Unless otherwise specified in 500.8(C)(6), equipment markings shall include: (1) class, (2) division, (3) material classification group, (4) equipment temperature, and (5) ____.

Hazardous (classified) locations are divided into certain categories and subcategories, otherwise known as ____.

Sealing compound shall ____.

When mixed with air, a flammable/combustible gas (or liquid-produced vapor) has a _____ of no more than 0.45 mm.

Equipment protection techniques may include explosionproof, dusttight, heremetic sealing, and ____.

____ locations contain ignitable or combustible elements (gases, dust, fibers, etc.) in quantities sufficient to produce explosive (or ignitable) mixtures.

All cut ends of intermediate metal conduit (IMC) and rigid metal conduit (RMC) shall be ____.

The simultaneous presence of flammable gases, flammable liquid-produced vapors, combustible liquid-produced vapors, or combustible dusts shall be considered when determining the ____ of the electrical equipment.

Garages used for parking or storage are ____.

Additional seals apply to the ____ of the Class I locations.

Class III, Division 1 and 2 portable lighting equipment shall have handles and ____.

The temperature marking for organic dusts that may dehydrate or carbonize shall not exceed the lower of either the ignition temperature or ____.

Conduit/cable system seals minimize the passage of ____ and prevent the passage of flames from one portion of the electrical installation to another through the conduit.

Electrical wiring and electrical utilization equipment located within 5 ft (1525 mm) of a vapor source shall be suitable for _____ locations.

The quantity of combustible dust that may be present and the ____ are factors that merit consideration in determining the classification and may result in an unclassified area.

Hazardous (classified) locations divide atmospheric identifications for Class I, Divisions 1 and 2, locations into ____.