A protection technique utilizing stationary gas detectors

Equipment enclosed in a manner that excludes dusts and does not permit arcs, sparks, or heat otherwise generated or liberated inside of the enclosure to cause ignition of exterior accumulations or atmospheric suspensions of a specified dust on or in the vicinity of the enclosure.

Enclosures constructed so that dust will not enter under specified test conditions.

Apparatus enclosed in a case that is capable of withstanding an explosion of a specified gas or vapor that may occur within it and of preventing the ignition of a specified gas or vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or vapor within, and that operates at such an external temperature that a surrounding flammable atmosphere will not be ignited thereby.

sealed against the entrance of an external atmosphere where the seal is made by fusion, for example, soldering, brazing, welding, or the fusion of glass to metal.

Electrical equipment immersed in a protective liquid in such a way that an explosive atmosphere that may be above the liquid or outside the enclosure cannot be ignited.

A circuit, other than field wiring, in which any arc or thermal effect produced under intended operating conditions of the equipment, is not capable, under specified test conditions, of igniting the flammable gas-air, vapor-air, or dust air mixture

Equipment having electrical/electronic circuitry that is incapable, under normal operating conditions, of causing ignition of a specified flammable gas-air, vapor-air, or dust-air mixture due to arcing or thermal means.

Locations have been classified depending on the properties of the flammable vapors, liquid, or gasses, or combustible dusts or fibers that may be present.

Flammable gases or vapor are present in air which is sufficient to produce explosive or ignitable mixtures.

Locations that has presence of combustible dust.

Locations that has the presence of ignitable fibers or flyings.

MESG

MIC

Acetylene

Flammable gas, flammable liquid-produced vapor, or combustible liquid-produced vapor mixed with air that may burn or explode, MESG value is less than or equal 0.45 mm, MIC ratio is less than or equal to 0.40 mm.

Flammable gas, flammable liquid-produced vapor, or combustible liquid-produced vapor mixed with air that may burn or explode, MESG value is greater than 0.45 mm and less than or equal to 0.75 mm, MIC ratio than 0.40 and less than or equal to 0.80.

Flammable gas, flammable liquid-produced vapor, or combustible liquid-produced vapor mixed with air that may burn or explode, MESG value > 0.75 mm, MIC ratio > 0.80.

Atmospheres containing combustible metal dusts, including aluminum, magnesium, and their commercial alloys, or other combustible dusts whose particle size, abrasiveness, and conductivity present similar hazards in the use of electrical equipment

Atmospheres containing combustible carbonaceous dusts that have more than 8 percent total entrapped volatiles.

Atmospheres containing combustible dusts not included in Group E or F, including flour, grain, wood, plastic, and chemicals.

Encloses the parts w/c could ignite the atmosphere by sparking or heating

Enclosure can withstand an internal explosion of flammable mixture that has penetrated into the interior, without suffering damage and w/o causing ignition in joints or openings.

An area where combustible dust or ignitable fibers and flyings are present continuously or for long periods of time in quantities sufficient to be hazardous.

An area where combustible dust or ignitable fibers and flyings are likely to exist occasionally under normal operation in quantities sufficient to be hazardous.

An area where combustible dust or ignitable fibers and flyings are not likely to occur under normal operation in quantities sufficient to be hazardous.

One or more generator sets, or batter systems where permitted, intended to provide power during the interruption of the normal electrical services or the public utility electrical service intended to provide power during interruption of service normally provided by the generating facilities on the premises.

A building or part thereof used to provide services or treatment to four or more patients at the same time.

A subsystem of the emergency system consisting of feeders and branch circuits supplying energy to task illumination, special power circuits, and selected receptacles serving areas and functions related to patient care, and which are connected to alternate power sources by one or more transfer switches during interruption of the normal power source.

Electrically powered equipment whose continuous operation is necessary to maintain a patient's life.

A system of circuits and equipment intended to supply alternate power to a limited number of prescribed functions vital to the protection of life and safety.

Buildings or portions of buildings in which medical, dental, psychiatric, nursing, obstetrical, or surgical care are provided.

A building or part thereof used for the medical, psychiatric, obstetrical, or surgical care, on a 24-hour basis, of four or more inpatients.

A transformer of the multiple-winding type, with the primary and secondary windings physically separated, which inductively couples its secondary winding to the grounded feeder systems that energize its primary winding.

In an area in which patients are normally cared for, the space with surfaces likely to be contacted by the patient or an attendant who can touch the patient.

Occupancy of any room or space for assembly of 100 persons or more.

These are any such building structure or portion thereof, contains a projection booth or stage platform or area for the presentation of theatrical or musical productions.

Flexible cables and cords approved for hard or extra-hard usage shall be permitted to be laid on floors where protected from contact by the general public.

The fixed wiring methods shall be metal raceways, flexible metal raceways, nonmetallic raceways encased in not less than 50 mm of concrete, Type MI, MC, or AC cable with an insulated EGC.

A permanently installed overhead strip light.

An adapter used to connect a multipole connector containing two or more branch circuits to multiple individual branch-circuit connectors.

Cables/conductors that are physically tied, wrapped, taped or periodically bound together.

A metal wireway containing pendant or flush receptacles.

A box containing pendant or flush-mounted receptacles attached to a multiconductor cable via strain relief or a multipole connector.

A border light installed on or in the stage.

Cables or conductors adjacent to one another but not in continuous contact with each other.

fed with portable cords/cables intended to be moved from a place to another.

The wall and arch that separates the stage from the auditorium (house).

A portable stand that contains a general-purpose luminaire or lampholder with guard for the purpose of providing general illumination on the stage or in the auditorium.

A luminaire (lighting fixture) with multiple lamps arranged in a row.

An adapter cable containing one male plug and two female cord connectors used to connect two loads to one branch circuit.

A building unit that floats on water, is moored in a permanent location, and has a premises wiring system served through connection by permanent wiring to an electricity supply system not located on the premises.