Zone 0, 1, and 2 Locations
Match the label statement to the marking that best describes an example of an entry required by 505.9(C)(2).
Area classification ---> Class 1 Zone Material group ---> IIC Symbol for equipment built to American standards ---> AEx Temperature classification ---> T6 Type(s) of protection designation ---> ia
An associated apparatus is an apparatus in which all the circuits are limited to 24 volts.
False 100
Conduit seals in Zone 1 locations shall be provided within ? for each conduit entering enclosures having type of protection "d" or "e."
a. 2" 505.16(B)(1)
Cables with a gas/vaportight continuous sheath capable of transmitting gases or vapors through the cable core shall not be required to be sealed except as required in 505.16(C)(2)(b), unless the cable is attached to process equipment or devices that may cause a pressure in excess of ? to be exerted at a cable end, in which case a seal, barrier, or other means shall be provided to prevent migration of flammables into an unclassified area.
a. 6" of water 505.16(C)(2)(c)
Equipment identified for Class I, Division 1 or Class I, Division 2 shall, in addition to being marked in accordance with 500.8(C), be permitted to be marked with ? .
a. I. and II. 505.9(C)(1)
Optical System with Interlock "op sh" minimizes the risk of ignition in explosive atmospheres from optical radiation where visible or infrared radiation is confined inside optical fiber or other transmission medium with interlock cut-off provided to reliably reduce the unconfined beam strength to safe levels within a specified time in case the confinement fails and the radiation becomes unconfined.
a. True 100
A power-supply cord used for a Zone 2 instrumentation connection cannot exceed three feet, and it must be of a type listed for extra-hard usage or for hard usage if protected by location.
a. True 505.17(B)(3)
A Zone 0 location is a location in which ignitible concentrations of flammable gases or vapors are present continuously, or ignitible concentrations of flammable gases or vapors are present for long periods of time.
a. True 505.5(B)(1)
The temperature marking specified in NEC 505.9(D)(1) shall not exceed the ? of the specific gas or vapor to be encountered.
a. autoignition temperature 505.9(D)
An optical fiber cable, installed in a Zone 0, Zone 1, or Zone 2 location, with or without current-carrying current ( ? optical fiber cable), shall be installed to address the associated fire hazard and sealed to address the associated explosion hazard in accordance with the requirements of Sections 505.15 and 505.16.
a. composite 505.9(F)
Electrical equipment for use in Zone 0, Zone 1, and Zone 2 locations that is designed for use in a range of ambient temperatures other than ? is considered to be special; and the ambient temperature range shall then be marked on the equipment, including either the symbol "Ta" or "Tamb" together with the special range of ambient temperatures, in degrees Celsius.
b. -20°C to +40°C 505.9(D)(1)
One of the conditions for allowing an enclosed space without a source of flammable gases or vapors, but with an opening into a Zone 2 location with a combustible gas detection system to utilize wiring practices suitable for unclassified installations is to provide an alarm that will sound at not more than ? of the lower flammable limit.
b. 20% 505.8(I)(3)(1)
The sealing compound used in Zone 0, Zone 1, and Zone 2 locations shall provide a seal against passage of gas or vapors through the seal fitting, shall not be affected by the surrounding atmosphere or liquids, and shall not have a melting point less than ? .
b. 200°F 505.16(D)(2)
The cross-sectional area of the conductors or optical fiber tubes (metallic or nonmetallic) permitted in a seal in a Zone 0, Zone 1, or Zone 2 location shall not exceed ? of the cross-sectional area of a rigid metal conduit of the same trade size unless it is specifically listed for a higher percentage of fill.
b. 25% 505.16(D)(5)
An area in which ignitible concentrations of flammable gases or vapors normally are prevented by negative mechanical ventilation but which may become hazardous as a result of failure or abnormal operation of the ventilation equipment would be classified as Zone 2.
b. False 505.5(B)(3)(3)
Suitability of equipment identified for Zone 0, Zone 1, and Zone 2 shall be determined by ? .
b. I., II., and III. 505.9(A)
Which protection technique shall be permitted for apparatus and associated apparatus in Zone 0, Zone1, or Zone 2 locations for which they are listed?
b. Intrinsic safety "i" 505.8(C)
An area in which equipment is operated or processes are carried on, of such a nature that equipment breakdown or faulty operations could result in the release of ignitible concentrations of flammable gases or vapors and also cause simultaneous failure of electrical equipment in a mode to cause the electrical equipment to become a source of ignition would be classified as ? .
b. Zone 1 505.5(B)(2)(3)
A type of protection used in Zone 1 and 2 locations, where the enclosure will withstand an internal explosion of a flammable mixture that has penetrated into the interior, without suffering damage and without causing ignition, through any joints or structural openings in the enclosure of an external explosive gas atmosphere consisting of one or more of the gases or vapors for which it is designed is ? .
b. flameproof "d" 100
A protection method applied to electrical equipment that does not produce arcs or sparks in normal service and under specified abnormal conditions, in which additional measures are applied so as to give increased security against the possibility of excessive temperatures and of the occurrence of arcs and sparks is type of protection ? .
b. increased safety "e" 100
Type PVC conduit and Type RTRC conduit shall be permitted in Zone 1 locations, where encased in a concrete envelope a minimum of 50 millimeters (two inches) thick and provided with not less than ? of cover measured from the top of the conduit to grade.
c. 24" 505.15(B)(1)(6)
Using the Zone system, atmospheres containing acetylene, hydrogen, or flammable gas, flammable liquid-produced vapor, or combustible liquid-produced vapor mixed with air that may burn or explode, having either a maximum experimental safe gap (MESG) value less than or equal to 0.50 millimeters or minimum igniting current ratio (MIC ratio) less than or equal to 0.45 millimeters are included in ? .
c. Group IIC 505.6(A)
Separate intrinsic safety type of protection "ic" systems, installed in Zone 2 locations, shall be installed in which of the following?
c. I. and III. 505.15(C)(1)
A protection method where electrical parts that could ignite an explosive atmosphere by either sparking or heating are enclosed in a compound in such a way that this explosive atmosphere cannot be ignited is type of protection ? .
c. encapsulation "m" 100
One of the requirements for using a gas detection system as a protection technique in industrial establishments is that the gas detection equipment must be ? for Zone 1 and detection of the specific gas or vapor that will be encountered.
c. listed 505.8(I)(1)(a)
Conduit and fittings, installed in Zone 0, Zone 1, and Zone 2, shall be made wrenchtight to prevent ? when fault current flows through the conduit system, and to ensure the explosionproof or flameproof integrity of the conduit system where applicable.
c. sparking 505.9(E)
The extension of the flexible cord within a ? raceway between the wet-pit and the power source for an electric submersible pump shall be permitted.
c. suitable 505.17(A)
A drain or vent located between a single process seal and a conduit or cable seal, sufficiently sized to prevent over pressuring the conduit or cable seal above ? , is one of the additional means permitted to be used to mitigate a single process seal failure.
d. 1,493 Pa 505.26(3)
In Zone 0 locations, seals shall be provided within ? of where a conduit leaves a Zone 0 location.
d. 10' 505.16(A)(1)
Refrigerant machinery rooms containing ammonia refrigeration systems, which are equipped with adequate mechanical ventilation that operate continuously or are initiated by a detection system at a concentration not exceeding ? , shall be permitted to be classified as "unclassified" locations.
d. 150 ppm 505.5(A)
Flameproof equipment with flanged joints, installed in Class I, Group IIC locations, shall have a minimum distance of ? to any solid obstacle that is not a part of the equipment (such as steelworks, walls, weather guards, mounting brackets, pipes, or other electrical equipment) unless the equipment is listed for a smaller distance of separation.
d. 40 mm Table 505.7(D)
Where gas detection equipment is used to protect the interior of a control panel to allow the use of Zone 2 electrical equipment, installation methods, and wiring practices, an alarm must sound when the reading reaches not more than ? of the lower flammable limit.
d. 40% 505.8(I)(4)
There shall be no uninsulated exposed parts, such as electrical conductors, buses, terminals, or components in Zone 0, 1, or 2 locations that operate at more than ? ( ? in wet locations).
d. none of the above 505.19
