IEC 60079-14:2013 - Explosive Atmospheres - Electrical Installations Design and Selection Professional Free Practice Test — 30 Questions

Question 1

An electrical installation is being designed for a Zone 1 hazardous area. The chosen cable for a critical process control circuit features a braided metallic armouring and a robust outer sheath made of a specific thermoplastic compound. The enclosure for the equipment connected to this cable is designed with the \'Ex d\' (flameproof) enclosure type of protection. Considering the requirements for maintaining the integrity of the \'Ex d\' enclosure and ensuring effective earthing of the metallic armouring, what type of cable gland is most appropriate for this application according to IEC 60079-14:2013?

Accepted Answer

A barrier gland designed to seal the outer sheath and provide electrical continuity for the metallic armouring.

Question 2

When designing electrical installations for a Zone 1 hazardous area, a project engineer is specifying cable glands for the termination of non-armoured cables. The primary objective is to maintain the integrity of the enclosure\'s ingress protection rating. What is the minimum ingress protection (IP) rating that the cable gland\'s seal around the cable sheath must achieve to comply with the requirements of IEC 60079-14:2013 for this specific application?

Accepted Answer

IP6X for dust and IPX5 for water

Question 3

An electrical engineer is tasked with designing the electrical installation for a new chemical processing plant. The installation includes a control panel located in a Zone 1 hazardous area. A flexible, unarmored cable with an overall diameter of 18 mm is to be used to connect a sensor to this control panel. According to the principles of IEC 60079-14, what type of cable gland is most appropriate for this specific application to ensure the integrity of the enclosure\'s protection?

Accepted Answer

A gland with a barrier seal suitable for an 18 mm outer diameter flexible cable.

Question 4

Consider an industrial facility operating a process in a Zone 1 hazardous area, classified for Group IIC gases. An \'Ex d\' certified control panel is to be installed, requiring the termination of a steel-wire armoured (SWA) cable. What is the primary consideration for selecting the appropriate cable gland to maintain the integrity of the \'Ex d\' enclosure and ensure safety in this environment?

Accepted Answer

The cable gland must be certified for 'Ex d' applications, suitable for the specific gas group (IIC), correctly terminate the SWA cable, and provide an effective seal to prevent the ingress of the explosive atmosphere into the enclosure.

Question 5

An engineer is tasked with designing an electrical installation for a Zone 2 hazardous area where the equipment enclosure is specified to have an Ingress Protection (IP) rating of IP65. The chosen cable gland is intended to be used with a specific type of unarmoured cable. Considering the requirements for maintaining the enclosure\'s integrity as per IEC 60079-14:2013, which characteristic of the cable gland\'s sealing arrangement is most critical to ensure the IP65 rating is achieved and maintained?

Accepted Answer

The gland's ability to create a robust seal against the cable's outer sheath using a dedicated sealing ring or cone.

Question 6

When designing electrical installations for a petrochemical facility operating in a Zone 1 hazardous area, an engineer is tasked with selecting appropriate cable glands for unarmoured cables featuring an elastomeric outer sheath. The primary objective is to ensure the integrity of the enclosure\'s protection against the ingress of flammable gases and to maintain mechanical security of the cable termination. What type of sealing mechanism within the cable gland is most critical for achieving these objectives with this specific cable type in this hazardous location?

Accepted Answer

A barrier seal that compresses the elastomeric outer sheath to prevent gas ingress and provide mechanical retention.

Question 7

Consider an industrial facility operating a process with a Zone 1 hazardous area classification. A new control panel is to be installed, and it will be supplied via an unarmoured cable with an elastomeric sheath. The cable entry point into the control panel enclosure requires a gland that ensures the integrity of the explosion protection. Which type of cable gland is most appropriate for this specific application according to the principles outlined in IEC 60079-14:2013?

Accepted Answer

A cable gland designed for unarmoured cables, providing both sealing and mechanical retention of the sheath.

Question 8

A chemical processing plant is installing new instrumentation in a Zone 1 hazardous area. The instrumentation cables are specified with an overall metallic braid for electromagnetic interference (EMI) screening and are to be terminated using cable glands. What is the primary consideration for selecting the cable gland in this scenario, ensuring compliance with IEC 60079-14:2013 regarding the termination of the metallic braid?

Accepted Answer

The cable gland must be designed to effectively seal around the metallic braid, maintaining an ingress protection rating of at least IP66 for the termination assembly.

Question 9

An industrial facility is installing new electrical equipment in a Zone 1 hazardous area. The chosen cables are non-armoured and feature an outer sheath specifically formulated for resistance to oils and hydrocarbons. Considering the requirements of IEC 60079-14:2013 for maintaining the integrity of electrical installations in explosive atmospheres, what type of cable gland is most appropriate for terminating these cables into an enclosure, ensuring both mechanical security and environmental protection?

Accepted Answer

A gland designed for sealing non-armoured cables, with sealing components compatible with oil and hydrocarbon resistance.

Question 10

An electrical engineer is tasked with installing a new control panel in a Zone 1 hazardous area, utilizing an enclosure with Type of Protection \'d\' (flameproof). The panel will be supplied via an unarmoured, multi-core flexible cable. What is the paramount consideration when selecting the appropriate cable gland for this installation to ensure compliance with IEC 60079-14:2013?

Accepted Answer

The cable gland must be certified for Zone 1 and suitable for the specific enclosure thread and the unarmoured flexible cable, ensuring the integrity of the flame path.

Question 11

A maintenance team is tasked with replacing a damaged cable gland on an Ex d enclosure in a Zone 1 hazardous area where the atmosphere is classified as IIB. The original gland was a specific type designed for a particular cable diameter and material. The available replacement gland is certified for Zone 1, IIB, and is suitable for the enclosure\'s thread, but it is designed for a slightly larger cable diameter and has a different sealing mechanism. What is the primary consideration for the installation team when selecting and installing this replacement gland to ensure compliance with IEC 60079-14:2013?

Accepted Answer

Verifying that the replacement gland maintains the enclosure's original protection concept and is correctly applied for the specific cable and environmental conditions.

Question 12

Consider an industrial facility where a new process unit is being commissioned, requiring the installation of electrical equipment within a Zone 1 hazardous area. The primary enclosure for a critical control panel has been certified with the explosion protection concept of \"flameproof enclosure\" (Ex d). A technician is tasked with selecting the appropriate cable gland for a multi-core power cable entering this enclosure. Which characteristic of the cable gland is paramount to ensure compliance with IEC 60079-14 for this specific application?

Accepted Answer

The cable gland must be certified for use with flameproof enclosures (Ex d) and maintain the integrity of the enclosure's explosion protection.

Question 13

An electrical installation is being designed for a chemical processing plant operating in a Zone 1 hazardous area, classified for a Group IIB explosive atmosphere. The installation requires the termination of an unarmoured, multi-core cable with a thermoplastic outer sheath. The equipment to which this cable will be connected has an enclosure rated to IP66. What fundamental characteristic must the selected cable gland possess to ensure compliance with IEC 60079-14:2013 for this specific application?

Accepted Answer

A barrier seal suitable for unarmoured cables in Group IIB atmospheres and an IP rating of at least IP66.

Question 14

When designing electrical installations for a Zone 0 environment utilizing an enclosure with flameproof (Ex d) protection, what is the primary consideration for selecting an appropriate cable gland, and how does this relate to the selection for an enclosure with increased safety (Ex e) in the same zone?

Accepted Answer

The gland must maintain the enclosure's flame path integrity and prevent the ingress of the explosive atmosphere, a requirement that generally makes glands suitable for Ex d also acceptable for Ex e installations in Zone 0, provided other conditions are met.

Question 15

A project engineer is tasked with designing the electrical installation for a new chemical processing plant. The plant will have several areas classified as Zone 2. A specific cable run involves a flexible cable featuring a non-metallic outer sheath and an internal metallic braiding for electromagnetic interference (EMI) shielding. The cable needs to be terminated into a control panel enclosure. Considering the requirements of IEC 60079-14:2013 for such an installation, what type of cable gland is most appropriate for this termination to ensure both electrical continuity and environmental protection?

Accepted Answer

A gland with a metallic body, providing a conductive path for the braiding, and incorporating a sealing ring that compresses against the non-metallic outer sheath.

Question 16

An electrical installation engineer is tasked with selecting a cable gland for a new process control system in a petrochemical plant. The installation involves routing a multi-core cable with a thermoplastic outer sheath and a braided metallic armour into an enclosure certified for Zone 2 hazardous areas. The cable\'s overall diameter is 25 mm. The engineer must ensure that the gland provides both effective sealing against environmental ingress and secure electrical continuity of the metallic armour to the enclosure\'s earthing system, as mandated by relevant standards for such installations. Which type of cable gland would be most appropriate for this specific application, considering the cable construction and the hazardous area classification?

Accepted Answer

A gland with a sealing ring for the outer sheath and a clamping mechanism for the metallic armour, ensuring earthing continuity.

Question 17

An electrical engineer is tasked with designing the electrical installation for a new chemical processing plant. The facility includes several areas classified as Zone 1. A specific section requires the installation of non-armoured cables featuring a thermoplastic outer sheath. When selecting the appropriate cable gland for entry into a Type of Protection \'d\' enclosure in this Zone 1 area, what is the primary consideration regarding the gland\'s design and function to maintain the integrity of the enclosure\'s protection concept?

Accepted Answer

The gland must provide an effective seal around the cable's outer sheath and sufficient mechanical retention to prevent strain on the conductors.

Question 18

An electrical engineer is tasked with designing the electrical installation for a chemical processing plant operating in a Zone 1 hazardous area. The installation involves connecting flexible elastomeric-sheathed cables to equipment enclosures protected by the \'Ex d\' (flameproof) type of protection. The cables are unarmoured. What is the primary consideration for selecting the appropriate cable gland to ensure the integrity of the explosion protection and the safety of the installation in this specific scenario?

Accepted Answer

The gland must provide effective sealing against the external environment and mechanical retention of the cable's outer sheath.

Question 19

An electrical installation engineer is tasked with designing the electrical connections for a process control system in a Zone 1 hazardous area. The chosen instrumentation cables feature a non-metallic outer sheath and a braided metallic armour. Considering the requirements of IEC 60079-14:2013 for ensuring the integrity of explosion-protected equipment and installations, what type of cable gland is most appropriate for terminating these cables into an Ex d enclosure?

Accepted Answer

A gland providing effective sealing against dust and moisture ingress and ensuring electrical continuity with the metallic armour.

Question 20

When designing electrical installations for a chemical processing plant operating in a Zone 2 hazardous area, a project engineer is specifying components for a control panel housing equipment protected by the \"increased safety\" (Ex e) concept. The control panel requires cable entry for a multi-core flexible cable. Considering the requirements of IEC 60079-14:2013, which type of cable gland certification would be the most appropriate and directly compliant for ensuring the integrity of the Ex e enclosure?

Accepted Answer

A cable gland certified for "increased safety" (Ex e) or a multi-certified gland that includes Ex e

Question 21

An electrical engineer is tasked with designing an installation for a chemical processing plant where a specific area has been classified as Zone 2. The design requires the use of cable glands to connect power and control cables to a junction box. Considering the requirements of IEC 60079-14:2013 for electrical installations in explosive atmospheres, what is the minimum ingress protection (IP) rating that the selected cable glands must provide to ensure the integrity of the junction box enclosure in this Zone 2 environment?

Accepted Answer

IP54

Question 22

A chemical processing plant is installing new instrumentation in a Zone 2 hazardous area. The control cabinets housing these instruments are designed with the \"increased safety\" (Ex e) protection concept. A critical aspect of the installation involves selecting appropriate cable glands for the incoming power and signal cables. Which type of cable gland certification is mandatory to ensure the continued integrity of the Ex e protection concept for these cabinets?

Accepted Answer

Certified for increased safety (Ex e)

Question 23

An electrical engineer is tasked with designing the electrical installation for a chemical processing plant operating in a Zone 1 hazardous area. The plant utilizes a control panel enclosure that has been certified with an Ingress Protection (IP) rating of IP65. The engineer needs to select a cable gland for an unarmoured cable entering this enclosure. What is the minimum IP rating the selected cable gland must achieve when correctly installed to maintain the enclosure\'s overall protection against environmental ingress?

Accepted Answer

IP65

Question 24

Consider an electrical enclosure certified with Type of Protection \'d\' (flameproof) intended for installation in an outdoor Zone 1 hazardous area characterized by significant dust accumulation and potential for high-pressure water spray. An installer is selecting a cable gland to terminate a multi-core cable into this enclosure. According to the principles outlined in IEC 60079-14:2013 concerning the selection and installation of cable glands to maintain enclosure integrity, what is the minimum ingress protection (IP) rating that the cable gland should possess to ensure adequate sealing against both dust and water ingress, thereby preserving the enclosure\'s safety characteristics?

Accepted Answer

IP66

Question 25

When designing an electrical installation for a Zone 0 environment within a chemical processing plant, a critical consideration is the selection of appropriate cable entry devices. An engineer is tasked with specifying cable glands for a new intrinsically safe (Ex i) control panel situated in an area classified as Zone 0. The chosen cable glands must not only provide effective sealing against the ingress of potentially explosive gas mixtures but also maintain the overall safety integrity of the intrinsically safe circuit. What is the paramount factor that dictates the selection of these cable glands in this specific application?

Accepted Answer

The gland's certification for Zone 0 and compatibility with the intrinsically safe (Ex i) protection concept.

Question 26

Consider an electrical installation in a Zone 1 hazardous area where a metallic conduit system is employed to provide a specific level of ingress protection for the enclosure. If the conduit system, when properly installed and sealed, is certified to maintain an ingress protection rating of IP67 against dust and water, what is the minimum ingress protection rating that the cable gland must exhibit when fitted to the enclosure to ensure the overall integrity of the enclosure\'s protection?

Accepted Answer

IP67

Question 27

An electrical engineer is tasked with selecting a cable gland for a new installation in a Zone 1 hazardous area. The cable to be used features a thermoplastic outer sheath and an internal metallic wire armouring. The enclosure into which the cable will enter is rated for IP66. Which of the following gland selection criteria is most critical for ensuring the safety and integrity of the installation according to IEC 60079-14:2013?

Accepted Answer

Ensuring effective electrical continuity between the metallic armouring and the gland's earth connection, alongside a secure grip on the thermoplastic outer sheath.

Question 28

An electrical engineer is specifying components for a new installation in a Zone 1 hazardous area, involving a control panel housing intrinsically safe equipment. The chosen power cable for this panel incorporates a tinned copper wire braiding for electromagnetic screening and as a supplementary protective conductor. Considering the requirements of IEC 60079-14:2013 for maintaining the integrity of the electrical installation, what specific characteristic must the selected cable gland possess to effectively manage this braided cable within the hazardous environment?

Accepted Answer

The cable gland must provide a secure and low-impedance termination of the metallic braiding to ensure continuity of the protective conductor.

Question 29

An electrical engineer is tasked with selecting a cable gland for a new installation within a Zone 1 hazardous area classified for the presence of flammable dust. The primary concern is to prevent any ingress of dust that could potentially lead to an ignition source or compromise the integrity of the explosion-protected equipment. Considering the stringent environmental conditions and the need for robust protection, which ingress protection (IP) rating for the cable gland would be most appropriate to ensure the highest level of safety and compliance with IEC 60079-14:2013 for this specific application?

Accepted Answer

IP66

Question 30

An electrical enclosure intended for installation in a Zone 1 hazardous area has been specified with a minimum ingress protection rating of IP54. A cable gland is to be used to terminate a flexible cable into this enclosure. What is the minimum ingress protection rating that the selected cable gland must possess to ensure the integrity of the enclosure\'s protection against dust and water ingress as per IEC 60079-14:2013?

Accepted Answer

IP54

IEC 60079-14:2013 - Explosive Atmospheres - Electrical Installations Design and Selection Professional Free Practice Test — 30 Questions

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