Hornbill Industrial Training Mock Compex Online Exam

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  • 1/90 Questions

    For workers in potentially explosive environments it is essential to understand:

    • The basic requirements of working in hazardous areas
    • The manufacturers literature
    • The manufacturing standards
    • Panel wiring diagrams
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About This Quiz

Hornbill Industrial Training provides CompEx training and certification, including CompEx Gas/Vapour, Dust, Mechanical, Refresher, Responsible Persons and Foundation courses.
This is a Hornbill Industrial Training Mock CompEx Online Exam.

Hornbill Industrial Training Mock Compex Online Exam - Quiz

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  • 2. 

    IEC divides equipment into Equipment Protection Levels EPLs. What are they?

    • Ga, Gb, Gc

    • Gd, Ge, Gn

    • Gia, Gib, Gic

    • Gx, Gy, Gz

    Correct Answer
    A. Ga, Gb, Gc
    Explanation
    IEC (International Electrotechnical Commission) divides equipment into Equipment Protection Levels (EPLs) for the purpose of classifying the level of protection provided against potential hazards. The correct answer options, Ga, Gb, and Gc, represent three different EPLs. These EPLs indicate the level of protection against potential explosions caused by flammable gases or vapors. Ga represents the highest level of protection, suitable for hazardous areas with the highest risk, while Gb and Gc represent lower levels of protection suitable for areas with lower risks.

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  • 3. 

    A power-on test is to be carried out on a flanged Ex d item of equipment after a detailed inspection. What is the minimum requirement of the enclosure:

    • Put at least one bolt back and hang a danger notice

    • Put at least half the bolts back and hang a danger notice

    • Put all bolts back spanner tight and check the flange gaps

    • Put no bolts back and leave it until the next inspection

    Correct Answer
    A. Put all bolts back spanner tight and check the flange gaps
    Explanation
    After a detailed inspection, the minimum requirement for the enclosure is to put all bolts back spanner tight and check the flange gaps. This ensures that the equipment is properly secured and the flange gaps are checked for any potential leaks or hazards. Hanging a danger notice alone would not be sufficient to ensure the safety and functionality of the equipment.

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  • 4. 

    Which of the following is not needed for combustion to occur:

    • Ignition source

    • Fuel supply

    • Enclosure

    • Oxygen

    Correct Answer
    A. Enclosure
    Explanation
    Combustion is a chemical reaction that requires three main components: fuel, oxygen, and an ignition source. The fuel is the material that undergoes combustion, while oxygen is necessary for the reaction to occur. The ignition source provides the initial heat energy needed to start the reaction. However, an enclosure is not needed for combustion to occur. An enclosure refers to a confined space or container, which is not essential for the combustion process. Combustion can take place in an open environment without any enclosure.

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  • 5. 

    Equipment marked IECExBAS06.0014X. What does the X indicate:

    • The equipment must be installed in a safe area

    • The equipment cannot be used outdoors

    • The equipment does not have an IP rating

    • Special conditions apply, refer to documentation

    Correct Answer
    A. Special conditions apply, refer to documentation
    Explanation
    The "X" in the equipment marking IECExBAS06.0014X indicates that special conditions apply to the equipment and these conditions can be found in the documentation. This means that there may be specific requirements or limitations for the use or installation of the equipment that need to be followed, and these details can be found in the accompanying documentation provided by the manufacturer or supplier.

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  • 6. 

    Cable glands entering a flameproof enclosure are required to meet what minimum thread engagements

    • 5 full threads

    • 8 full threads

    • 3 full threads

    • 10 full threads

    Correct Answer
    A. 5 full threads
    Explanation
    Cable glands entering a flameproof enclosure are required to meet a minimum of 5 full threads. This means that the cable glands must have at least 5 complete turns or rotations when inserted into the enclosure to ensure a secure and tight fit. This is important in flameproof enclosures as it helps to prevent the entry of any flammable gases or substances, reducing the risk of explosions or fires. Having a sufficient number of thread engagements ensures a reliable and safe connection between the cable gland and the enclosure.

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  • 7. 

    Which of the following is not required for combustion of a flammable material

    • Oxygen

    • An Enclosure

    • Ignition source

    • Fuel

    Correct Answer
    A. An Enclosure
    Explanation
    An enclosure is not required for the combustion of a flammable material. Combustion can occur in an open environment where there is sufficient oxygen, an ignition source, and fuel. An enclosure, such as a closed container or confined space, can enhance the combustion process by containing the heat and allowing it to build up, leading to more intense and potentially dangerous fires. However, it is not necessary for the actual combustion to take place.

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  • 8. 

    The Atex 95 Directive is concerned with:

    • The health and safety of workers

    • The electricity at work act

    • The design and trade of explosion protection equipment

    • Standardisation of electrical voltages

    Correct Answer
    A. The design and trade of explosion protection equipment
    Explanation
    The Atex 95 Directive is concerned with the design and trade of explosion protection equipment. This means that it focuses on regulating and ensuring the safety of equipment that is specifically designed to prevent and protect against explosions. The directive aims to establish standards and guidelines for the design, manufacturing, and trade of such equipment to ensure its effectiveness and compliance with safety regulations. This is important to prevent accidents and protect workers from potential hazards in explosive environments.

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  • 9. 

    What are the requirements of threaded entry into an Ex d enclosure:

    • Three fully engaged threads

    • Five fully engaged threads

    • Eight fully engaged threads

    • Ten fully engaged threads

    Correct Answer
    A. Five fully engaged threads
    Explanation
    Threaded entry into an Ex d enclosure requires five fully engaged threads. This means that the threads on the entry point must be completely threaded into the enclosure to ensure a secure and tight fit. Having five fully engaged threads ensures that the connection is strong and reduces the risk of any leaks or hazardous substances escaping from the enclosure.

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  • 10. 

    How should finely stranded conductors be terminated:

    • Twisting the strands

    • Soldering the strands

    • Fit coloured sleeving

    • Fit cable lugs or core-end sleeves

    Correct Answer
    A. Fit cable lugs or core-end sleeves
    Explanation
    Finely stranded conductors should be terminated by fitting cable lugs or core-end sleeves. This is because the fine strands of the conductor can easily become damaged or frayed if left exposed, leading to poor electrical connections or potential safety hazards. By fitting cable lugs or core-end sleeves, the strands are protected and secured, ensuring a reliable and safe termination.

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  • 11. 

    IEC 60079-14 requires levels of attainment for workers, What is required for technicians:

    • Only evidence of having the necessary skills for the scope of work

    • Only evidence of having the necessary skills for the scope of work and competence across a range of activities

    • Evidence of having the necessary skills for the scope of work and competence across a range of activities and of relevant knowledge and understanding of protection types

    • Have HNC in Engineering

    Correct Answer
    A. Evidence of having the necessary skills for the scope of work and competence across a range of activities and of relevant knowledge and understanding of protection types
    Explanation
    The correct answer is evidence of having the necessary skills for the scope of work and competence across a range of activities and of relevant knowledge and understanding of protection types. This requirement ensures that technicians have not only the necessary skills for their specific job, but also the ability to perform a variety of tasks and have knowledge of different protection types. This ensures that they are well-rounded and capable of handling different situations and tasks within their field. Having this level of competence and knowledge is essential for technicians to effectively carry out their responsibilities.

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  • 12. 

    Which one of the following statements represents the presence flammable mixture in Zone 0

    • Not likely to be present in normal operations

    • Not present during normal operations

    • Present continuously, or for long periods

    • Present in normal operations occasionally 

    Correct Answer
    A. Present continuously, or for long periods
    Explanation
    The correct answer is "present continuously, or for long periods." This statement accurately describes the presence of a flammable mixture in Zone 0. Zone 0 refers to an area where explosive gas is likely to be present continuously or for long periods of time, such as inside a tank or a vessel. The other options suggest that the flammable mixture is not likely to be present or only present occasionally, which does not align with the characteristics of Zone 0.

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  • 13. 

    Before working in a hazardous area which one of the following is necessary to understand

    • Manufacturers documentation

    • The basic requirements for working in zoned areas

    • Circuit Diagrams

    • How the equipment operates

    Correct Answer
    A. The basic requirements for working in zoned areas
    Explanation
    To work in a hazardous area, it is necessary to understand the basic requirements for working in zoned areas. This includes knowledge of the safety protocols, regulations, and precautions that need to be followed while working in such areas. Understanding these requirements is crucial to ensure the safety of oneself and others in the hazardous environment. It helps in preventing accidents, minimizing risks, and effectively managing any potential dangers that may arise in zoned areas.

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  • 14. 

    What is the design ambient temperature if not marked on the equipment:

    • -10oC to +20oC

    • -20oC to +40oC

    • -30oC to +60oC

    • -40oC to +80oC

    Correct Answer
    A. -20oC to +40oC
    Explanation
    The design ambient temperature refers to the range of temperatures within which the equipment is designed to operate effectively and safely. In this case, if the design ambient temperature is not marked on the equipment, it can be assumed to be -20oC to +40oC. This range allows for a moderate level of temperature variation, providing a suitable operating environment for the equipment.

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  • 15. 

    Pressure piling can result when:

    • Heavy equipment is mounted on piles

    • An ignition in one part of an enclosure causes higher explosion pressure in another part

    • There is a build up of pressure causing material fatigue

    • The gas pressure causes a vent to open

    Correct Answer
    A. An ignition in one part of an enclosure causes higher explosion pressure in another part
    Explanation
    When an ignition occurs in one part of an enclosure, it can cause a chain reaction leading to higher explosion pressure in another part. This is because the initial ignition releases energy and heat, which can ignite other flammable substances or gases in the enclosure. As the combustion process continues, the pressure within the enclosure increases, potentially causing an explosion. This phenomenon is known as pressure piling and can be dangerous if proper safety measures are not in place.

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  • 16. 

    The requirement for glands entering Ex n equipment after 2007 are

    • Certified meeting the requirements on IEC60079-0

    • EX d Barrier Gland

    • Ex e Gland

    • Ex d Gland

    Correct Answer
    A. Certified meeting the requirements on IEC60079-0
    Explanation
    The correct answer is "Certified meeting the requirements on IEC60079-0." This means that the glands entering Ex n equipment after 2007 must be certified and meet the requirements stated in the IEC60079-0 standard. This standard specifies the general requirements for equipment used in explosive atmospheres, ensuring that the equipment is safe to use in such environments. Therefore, it is essential for the glands to be certified and compliant with this standard to ensure the safety and functionality of the Ex n equipment.

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  • 17. 

    An item of equipment marked II without an A, B or C can be used:

    • The equipment is unsuitable for any area

    • The equipment can only be used in IIA areas

    • The equipment can be used in all gas group areas

    • The equipment can only be used in IIB area

    Correct Answer
    A. The equipment can be used in all gas group areas
    Explanation
    The correct answer is that the equipment can be used in all gas group areas. This means that the equipment is suitable for use in any area, regardless of the gas group classification. The absence of A, B, or C markings indicates that the equipment is not limited to specific gas group areas and can be used safely in all of them.

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  • 18. 

    During a Hornbill Industrial Training mock session focusing on machine maintenance and safety, what is the recommended action when a critical pressure gauge on a hydraulic press registers within 5% above the normal operating range?

    • Continue operating the machine as long as the gauge does not exceed 10% of the normal range.

    • Stop the machine immediately and perform a standard safety check according to the operations manual. 

    • Adjust the pressure release valve to immediately lower the pressure to the normal operating range.

    • Record the pressure reading and report it to the maintenance department at the end of the shift.

    Correct Answer
    A. Stop the machine immediately and perform a standard safety check according to the operations manual. 
    Explanation
    In an industrial training scenario, particularly one focused on machine maintenance and safety like Hornbill Industrial Training, the safety of operations is paramount. When a critical pressure gauge indicates a measurement above the normal operating range, even if it's only by 5%, it could potentially signal an underlying issue that may lead to equipment failure or safety hazards. The recommended action, therefore, would be to stop the machine immediately to prevent any risk of damage or injury and to conduct a safety check as per the protocols outlined in the operations manual. This reflects the best practice in industrial settings, which is to err on the side of caution when any potential safety issue arises.

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  • 19. 

    What is the minimum IP rating of Ex n equipment

    • IP 20

    • IP 44

    • IP 54

    • IP 65

    Correct Answer
    A. IP 54
    Explanation
    Ex n equipment refers to equipment that is designed for use in potentially explosive atmospheres. The IP rating, also known as the Ingress Protection rating, indicates the level of protection provided by the equipment against solid objects and liquids. In this case, the minimum IP rating required for Ex n equipment is IP 54. This means that the equipment is protected against dust and limited ingress of water, making it suitable for use in hazardous environments.

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  • 20. 

    Cable glands installed into Ex n boxes after 2007 are required to be:

    • Certified Ex d gland

    • Certified Ex e gland

    • Certified Barrier gland

    • Certified to IEC 60079

    Correct Answer
    A. Certified to IEC 60079
    Explanation
    After 2007, cable glands installed into Ex n boxes are required to be certified to IEC 60079. This certification ensures that the cable glands meet the international standards for electrical equipment used in explosive atmospheres. The IEC 60079 standard specifies the requirements for the design, construction, testing, and marking of electrical equipment to ensure safety in hazardous areas. By being certified to this standard, the cable glands are deemed suitable for use in potentially explosive environments, providing assurance of their safety and reliability.

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  • 21. 

    Ex d equipment is called flameproof because:

    • It contains flammable materials

    • If the equipment is on fire it will continue to function

    • It will contain an internal explosion

    • It's too heavy to be used

    Correct Answer
    A. It will contain an internal explosion
    Explanation
    Ex d equipment is called flameproof because it is designed to contain an internal explosion. This means that if an explosion occurs within the equipment, it will not propagate to the surrounding environment. The equipment is constructed in such a way that it can withstand and contain the pressure and flames generated by an internal explosion, preventing it from causing further damage or igniting any flammable materials in the vicinity. This makes it a safer option for use in hazardous environments where there is a risk of explosions.

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  • 22. 

    Ex e equipment signifies:

    • Flameproof

    • Increased safety

    • Purged

    • Intrinsically safe

    Correct Answer
    A. Increased safety
    Explanation
    Ex e equipment signifies increased safety. This means that the equipment is designed and constructed in a way that reduces the risk of ignition and the potential for the creation of sparks or excessive temperatures. Increased safety equipment is suitable for use in hazardous environments where there may be flammable gases, vapors, or dust present. It provides a higher level of protection compared to other types of equipment, such as flameproof or purged, ensuring a safer working environment.

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  • 23. 

    Which of the following is a GRADE of inspection:

    • Close

    • Periodic

    • Frequent

    • Sample

    Correct Answer
    A. Close
    Explanation
    A close inspection refers to a detailed examination of something, typically done with great attention to detail and thoroughness. It involves closely examining every aspect or component of the item being inspected. Close inspections are often conducted to ensure that there are no defects, errors, or issues that may have been missed during previous inspections. This type of inspection is usually done when a high level of accuracy and precision is required.

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  • 24. 

    ATEX divides equipment into groups and categories. What are they?

    • Group I - categories 1,2,3

    • Group II - Categories 1,2,3

    • Group III - Categories 1,2,3

    • Group IIII - Categories 1,2,3

    Correct Answer
    A. Group II - Categories 1,2,3
    Explanation
    ATEX divides equipment into groups and categories for the purpose of classifying them based on their potential for causing an explosion in hazardous environments. The correct answer states that Group II is divided into Categories 1, 2, and 3. This means that equipment in Group II is intended for use in areas where explosive atmospheres caused by gases, vapors, or mists are likely to occur occasionally or for short periods. Category 1 represents the highest level of protection, suitable for areas with a high risk of explosion, while Category 3 represents the lowest level of protection, suitable for areas with a lower risk of explosion.

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  • 25. 

    On an area classification drawing what would represent Zone 1:

    • Circles

    • Cross hatching

    • As symbols shown on the drawing

    • Slanted lines

    Correct Answer
    A. As symbols shown on the drawing
    Explanation
    Zone 1 on an area classification drawing would be represented by symbols shown on the drawing. This means that specific symbols or icons would be used to indicate the presence of Zone 1 hazardous areas. These symbols could vary depending on the industry or specific regulations being followed. Using symbols helps to clearly identify and communicate the location of Zone 1 areas, which are defined as areas where flammable gases, vapors, or liquids are likely to be present in normal operating conditions.

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  • 26. 

    The purpose of Barriers is to:

    • Limit the maximum energy flow to apparatus

    • Allow any apparatus to be installed

    • Allow apparatus only marked Ex i to be installed

    • Limit the maximum temperature of the apparatus

    Correct Answer
    A. Limit the maximum energy flow to apparatus
    Explanation
    Barriers are used to limit the maximum energy flow to apparatus. This means that they control and restrict the amount of energy that can be transmitted to the apparatus, ensuring that it does not exceed a certain level. By doing so, barriers help to prevent damage or malfunction of the apparatus, ensuring its safe operation. This is an important safety measure in hazardous environments where excessive energy flow can pose a risk.

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  • 27. 

    The minimum gap between Ex d flanged joints and other obstructions in a IIC environment is:

    • 10mm

    • 20mm

    • 30mm

    • 40mm

    Correct Answer
    A. 40mm
    Explanation
    In an IIC environment, the minimum gap between Ex d flanged joints and other obstructions is 40mm. This is necessary to ensure proper ventilation and prevent the buildup of explosive gases. A larger gap allows for better dissipation of heat and reduces the risk of ignition or explosion. It also provides enough space for maintenance and inspection activities to be carried out safely. Therefore, a 40mm minimum gap is required to meet the safety standards in an IIC environment.

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  • 28. 

    The fixings of Ex d equipment should:

    • All be spanner tight

    • Be tightened using a torque wrench set at 50Nm

    • Have only alternate bolts tightened

    • Be missing

    Correct Answer
    A. All be spanner tight
    Explanation
    The fixings of Ex d equipment should all be spanner tight. This means that all the fixings should be tightened securely using a spanner tool. This ensures that the equipment is properly sealed and prevents any potential leakage or release of hazardous substances. Tightening all the fixings also helps to maintain the integrity of the equipment and prevent any accidental dislodgement or damage.

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  • 29. 

    Ex e equipment installed in 2005, which gland is not acceptable

    • Uncertified plastic

    • Uncertified E1W

    • E1W ex e

    • E1W Ex d

    Correct Answer
    A. Uncertified plastic
    Explanation
    The correct answer is "Uncertified plastic" because when it comes to Ex e equipment, the use of uncertified plastic materials is not acceptable. Ex e refers to a type of electrical equipment that is designed to prevent the occurrence of arcs, sparks, or hot surfaces that could ignite explosive atmospheres. In order to ensure the safety and reliability of Ex e equipment, it is crucial to use certified materials that meet the necessary standards and regulations. Uncertified plastic materials may not have undergone the required testing and certification processes, therefore making them unsuitable for use in Ex e equipment.

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  • 30. 

    The numbers after letters IP represent

    • Solid particles and liquids

    • Solid particles and mechanical protection

    • Dust particles and condensation

    • Supply voltage and water pressure

    Correct Answer
    A. Solid particles and liquids
    Explanation
    The numbers after letters IP represent the level of protection provided by the enclosure against solid particles and liquids. The IP code is an international standard that classifies the degree of protection provided by electrical enclosures. The first digit indicates the level of protection against solid particles, such as dust, while the second digit indicates the level of protection against liquids, such as water. Therefore, the correct answer is "Solid particles and liquids."

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  • 31. 

    Equipment marked Ex e II T6 can be used in?

    • All gas groups

    • IIC only

    • IIA only

    • In combustible dusts only

    Correct Answer
    A. All gas groups
    Explanation
    The equipment marked Ex e II T6 can be used in all gas groups. This means that it is suitable for use in environments where there is a risk of explosive gases present, regardless of the specific gas group classification. The T6 designation indicates that the equipment can operate safely in environments with a maximum surface temperature of 85°C. Therefore, this equipment is versatile and can be used in a wide range of hazardous areas where explosive gases may be present.

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  • 32. 

    Live working under permit without a gas free certificate may be allowed if:

    • You are wearing PPE

    • You are working on IS circuits

    • The supply is SELV

    • The equipment Ex e

    Correct Answer
    A. You are working on IS circuits
    Explanation
    Working on IS (Intrinsically Safe) circuits means working on circuits that are designed to prevent the ignition of hazardous materials. These circuits are specifically designed to be safe in hazardous environments, so the need for a gas free certificate may not be necessary in this case.

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  • 33. 

    Equipment supplied with a greater than normal ambient temperature, which markings is relevant?

    • Ex d II T3 T65

    • Ex d II 60C T3

    • Ex e ii T3 40degC amb

    • Ex e II T3 -20C<Ta<+60C

    Correct Answer
    A. Ex e II T3 -20C<Ta<+60C
    Explanation
    The correct answer is "Ex e II T3 -20C

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  • 34. 

    Which is the ATEX installation standard?

    • IEC 60079-0

    • IEC 60079-10

    • IEC 60079-14

    • IEC 60079-17

    Correct Answer
    A. IEC 60079-14
    Explanation
    The correct answer is IEC 60079-14. This standard specifically addresses the design, selection, installation, inspection, and maintenance of electrical installations in explosive atmospheres. It provides guidance on the requirements for the safe installation of electrical equipment and systems in hazardous areas, ensuring that they do not become a source of ignition. This standard is important for industries dealing with flammable substances, such as oil and gas, chemical, and pharmaceutical industries, to prevent accidents and ensure the safety of personnel and equipment.

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  • 35. 

    Equipment for use in Hydrogen area where EPL is Gc Cat 3, the equipment will be marked with 

    • Ex e IIB T4

    • Ex n II T4

    • Ex d IIB T4

    • Ex e IIA T5

    Correct Answer
    A. Ex n II T4
    Explanation
    The correct answer, "Ex n II T4," indicates that the equipment is suitable for use in a hydrogen area with a gas group of II and a maximum surface temperature of T4. The "Ex n" marking signifies that the equipment is designed for non-sparking operations and is suitable for use in a potentially explosive atmosphere. The "II" classification indicates that the equipment is suitable for use in areas with a high risk of explosion. The "T4" rating indicates that the equipment can operate safely at a maximum surface temperature of 135°C.

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  • 36. 

    What apparatus can be connected to a Zenner barrier:

    • Any apparatus

    • Simple apparatus marked Ex i

    • Only that specified in documentation

    • Only uncertified apparatus

    Correct Answer
    A. Only that specified in documentation
    Explanation
    The correct answer is "Only that specified in documentation." This means that the Zenner barrier can only be connected to the specific apparatus that is mentioned and approved in the documentation. It cannot be connected to any other apparatus or uncertified devices. This ensures that the Zenner barrier functions properly and safely with the designated equipment.

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  • 37. 

    What grade of inspection would the dismantling of a gland take:

    • Visual

    • Close

    • Detailed

    • Periodic

    Correct Answer
    A. Detailed
    Explanation
    The dismantling of a gland would require a detailed inspection. This is because dismantling involves taking apart the gland and examining each component closely to ensure that it is in proper working condition. A detailed inspection would involve thoroughly examining each part of the gland, checking for any signs of damage or wear, and ensuring that all components are functioning correctly. This level of inspection is necessary to ensure the gland is in optimal condition and to identify any potential issues that may need to be addressed.

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  • 38. 

    Aluminium cables are used in hazardous areas, what is the minimum CSA?

    • Less than 6mm

    • Less than10mm

    • Greater than 16mm

    • Greater than 25mm

    • Option 5

    Correct Answer
    A. Greater than 16mm
    Explanation
    Aluminium cables are used in hazardous areas because they have better resistance to corrosion and are lighter than other materials. The minimum CSA (cross-sectional area) required for these cables is greater than 16mm. This is because a larger CSA ensures that the cables can handle higher current loads and reduces the risk of overheating, which is crucial in hazardous areas where safety is a priority.

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  • 39. 

    Which gas group includes Hydrogen:

    • I

    • IIA

    • IIB

    • IIC

    Correct Answer
    A. IIC
    Explanation
    Gas groups are used in hazardous area classification, particularly in relation to electrical equipment used in environments where explosive atmospheres may be present. Group IIC is the gas group that includes gases with the highest level of hazard due to their low ignition energy, and hydrogen is among these because of its ease of ignition and explosive potential under certain conditions. This classification is important for selecting appropriate and safe equipment for use in areas where hydrogen is present.

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  • 40. 

    A vapour will ignite without an ignition source when it reaches it's:

    • Flash point

    • Fire point

    • Ignition temperature

    • Boiling point

    Correct Answer
    A. Ignition temperature
    Explanation
    The ignition temperature refers to the minimum temperature at which a substance can ignite spontaneously without the need for an external ignition source. This means that once the vapour reaches its ignition temperature, it will ignite on its own, even without the presence of an ignition source such as a flame or spark. This is different from the flash point, which is the minimum temperature at which a substance can emit enough vapour to ignite when exposed to an ignition source. The fire point is the temperature at which the substance continues to burn after ignition has occurred. The boiling point, on the other hand, is the temperature at which a substance changes from a liquid to a gas state.

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  • 41. 

    What does the T rating of equipment represent?

    • The equipment will reach this temperature in normal operation

    • The equipment will reach it's flash point in normal operation

    • The relevant surfaces of the equipment will not reach this temperature in normal operation

    • The equipment will exceed the temperature rating in normal operation

    Correct Answer
    A. The relevant surfaces of the equipment will not reach this temperature in normal operation
    Explanation
    The T rating of equipment represents that the relevant surfaces of the equipment will not reach this temperature in normal operation. This means that the equipment is designed to operate within a certain temperature range, and the T rating ensures that the equipment will not exceed this specified temperature during normal use. It indicates that the equipment is safe to use without the risk of overheating or causing damage due to high temperatures.

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  • 42. 

    What letters are used by the IEC for Equipment protection levels:

    • A,b,c

    • B,d,c

    • W,x,y

    • C,B,E

    Correct Answer
    A. A,b,c
    Explanation
    The IEC (International Electrotechnical Commission) uses the letters a, b, and c for Equipment protection levels. These letters are used to classify the degree of protection provided by electrical equipment against various environmental conditions, such as dust, water, and mechanical impacts. Each letter represents a different level of protection, with "a" indicating the highest level of protection and "c" indicating the lowest level.

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  • 43. 

    Which protection types can be used in an area requiring EPL Ga and category 1G

    • Ex d

    • Ex e

    • Ex ia

    • Ex ib

    Correct Answer
    A. Ex ia
    Explanation
    Ex ia is the correct answer because it is a protection type suitable for an area requiring EPL Ga and category 1G. Ex ia stands for "intrinsic safety" and it is a method of protection where the electrical energy in the circuit is limited to prevent ignition of hazardous substances. This protection type is commonly used in areas where explosive gases are present and it ensures that any electrical equipment used in the area will not produce sparks or excessive heat that could ignite the surrounding atmosphere.

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  • 44. 

    Non IS and IS equipment is installed in the same enclosure. What is the minimum gap between terminals of each type:

    • 3mm

    • 6mm

    • 30mm

    • 50mm

    Correct Answer
    A. 50mm
    Explanation
    The minimum gap between terminals of each type is 50mm. This is necessary to ensure proper insulation and prevent any potential interference or short-circuiting between the non IS and IS equipment. A larger gap allows for better separation and reduces the risk of any electrical hazards.

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  • 45. 

    What should the maximum earth impedance be for a Zenner barrier:

    • 1MΩ

    • 100Ω

    • 10Ω

    • 1Ω

    Correct Answer
    A. 1Ω
    Explanation
    The maximum earth impedance for a Zenner barrier should be 1Ω because a Zenner barrier is used in hazardous areas to prevent the transmission of electrical energy, and a low earth impedance ensures that any potential fault currents are quickly and safely dissipated to the earth. A higher earth impedance could result in the build-up of dangerous levels of electrical energy, increasing the risk of explosions or fires in the hazardous area.

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  • 46. 

    Newly installed Ex d equipment may be installed in which of the following

    • Areas needing EPL Gc ( Cat 3G) equipment

    • Areas needing EPL Gb and Gc (2G & 3G) equipment

    • Areas needing EPL Ga (Cat 1G) equipment

    • Only areas needing EPL Gb (Cat 2G) equipment

    Correct Answer
    A. Areas needing EPL Gb and Gc (2G & 3G) equipment
    Explanation
    Newly installed Ex d equipment may be installed in areas needing EPL Gb and Gc (2G & 3G) equipment because Ex d equipment is designed for use in hazardous areas where explosive gases and dust may be present. EPL Gb and Gc equipment are specifically designed for use in hazardous areas with different levels of gas and dust explosion risks. Therefore, newly installed Ex d equipment can be installed in areas that require both EPL Gb and Gc equipment to ensure safe operation in these hazardous environments.

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  • 47. 

    Cat 2 equipment may be installed in

    • Zone 2 & 21

    • Zone 20, 21 & 22

    • Zone 1 & 21 and less arduous areas

    • Zone 0 & 20

    Correct Answer
    A. Zone 1 & 21 and less arduous areas
    Explanation
    Cat 2 equipment may be installed in Zone 1 & 21 and less arduous areas because it is designed to be used in areas where there is a risk of the presence of flammable gases or vapors (Zone 1) and/or combustible dust (Zone 21). Additionally, it can also be used in less hazardous areas where the risk is lower (less arduous areas).

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  • 48. 

    The T rating e.g. T5 marked on certified equipment indicates what

    • Will not reach the flashpoint of the gas in normal operation

    • Is deigned to reach the temperature of the T rating

    • Will not reach the ignition temperature of any dust or gas in normal operation

    • Will not exceed the temperature represented by T rating during normal or specified fault conditions

    Correct Answer
    A. Will not exceed the temperature represented by T rating during normal or specified fault conditions
    Explanation
    The T rating, such as T5 marked on certified equipment, indicates that the equipment will not exceed the temperature represented by the T rating during normal or specified fault conditions. This means that the equipment is designed to operate within a specific temperature range and will not overheat or reach temperatures that could cause ignition or flashpoint of any dust or gas in normal operation. The T rating provides assurance that the equipment is safe to use in potentially hazardous environments where there may be flammable substances present.

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  • 49. 

    Components such as an Switch or terminal suitable for installation within certified equipment has what additional letter added to the certification number, what letter is used?

    • X

    • U

    • A

    • C

    Correct Answer
    A. U
    Explanation
    Certified equipment components, such as a Switch or terminal, have an additional letter "U" added to the certification number. This indicates that the component is suitable for installation within certified equipment.

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Quiz Review Timeline (Updated): Nov 25, 2024 +

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  • Current Version
  • Nov 25, 2024
    Quiz Edited by
    ProProfs Editorial Team
  • Jun 18, 2019
    Quiz Created by
    R.scaplehorn

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