Elexcellence: Electrical Heat Tracing In Hazardous Areas! Trivia Quiz

20 Questions | Total Attempts: 12

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Elexcellence: Electrical Heat Tracing In Hazardous Areas! Trivia Quiz

Excellence: electrical heat tracing in hazardous areas! When you introduce fire into a hazardous area, you may be causing more dangers that there could have been if you didn’t. By taking this quiz, you will get to learn how to heat pipes while pausing more hazards to the surrounding. Give it a try and learn more about using electricity at your workplace.


Questions and Answers
  • 1. 
    The trace heating system ELSR-N-Ex is rated T6. Can it be used in T-Class T2?
    • A. 

      Yes, when an additional temperature limiter is used

    • B. 

      No, T2 can be up to 300°C which exceeds the maximum exposure temperature of ELSR-N

    • C. 

      Yes, T6 is more restrictive than T2

    • D. 

      No, ATEX and IECEx regulations mandate that an apparatus can only be used in the T-Class it is marked for

  • 2. 
    A customer has a crude oil application and wants to maintain 65°C on a pipe. What T-Class do you specify for this?
    • A. 

      T6 because the maintain temperature is below 85°C

    • B. 

      T3 because crude oil is a hydrocarbon

    • C. 

      None, this has to be specified by the customer

    • D. 

      That depends on the heater I am selecting for that application

  • 3. 
    Which standard(s) deal(s) with the design and installation of electric heat tracing?
    • A. 

      IEC 60079-14

    • B. 

      IEC 60079-30-2

    • C. 

      IEC 60079-31

    • D. 

      Both A) and B)

  • 4. 
    You would like to use a series heater in a Zone 22 application in “controlled design”. What temperature limiter do you choose?
    • A. 

      Limiter with manual reset

    • B. 

      No limiter, but temperature controller with fault indication and durability of at least 250000 switching cycles

    • C. 

       Limiter with automatic reset and switching capacity of 120% of the connected circuit

    • D. 

      Either or c) is possible

  • 5. 
    Which condition does not need to be considered for stabilised design?
    • A. 

      Still air

    • B. 

      Maximum start-up temperature

    • C. 

      Maximum ambient temperature or 40°C, whichever is higher

    • D. 

      10% overvoltage

  • 6. 
    What is the maximum heater sheath temperature you can design for a trace heating circuit in T4?
    • A. 

      A) 95°C

    • B. 

      B) 100°C

    • C. 

      C) 130°C

    • D. 

      D) 135°C

  • 7. 
    A customer wants you to design a trace heating circuit for Zone 20. What do you do?
    • A. 

      I inform the customer that there is no certified heat tracing availible on the market for this application

    • B. 

      The circuit needs to be designed in the same way as for Zone 21 plus one extra limiter to cover the second independent fault

    • C. 

      The circuit needs to be designed in the same way as for Zone 21 plus the plant owner needs to get a specific permission from his local authorities

    • D. 

      A Zone 21 design can be used if hot components get an additional protection from direct contact to dust (e.g. trace heater under a dust proof thermal insulation)

  • 8. 
    A trace heating circuit is to be operated in „controlled design“ in  Zone 1 or 21 (Canada and US: Class I or II Div 2). Is it recommended to place the sensor of the temperature limiter in direct contact to the trace heater?
    • A. 

      No, it could get loose over time due to vibrations or mechanical stress and then sense a temperature which is too low

    • B. 

      Yes, the trace heater is the hottest part in the installed heating system, and this is the only way to measure its absolute temperature.

    • C. 

      Yes, this is the only permitted method as per IEC 60079-14

    • D. 

      Both B) and C) are correct

  • 9. 
    What are the minimum required components in a certified trace heating system?
    • A. 

      Trace heater, power termination, end termination, temperature sensor

    • B. 

      Trace heater, power termination, end termination, junction box

    • C. 

      Trace heater, power termination, end termination, sheath temperature determination

    • D. 

      Trace heater, power termination, end termination, temperature controller, temperature sensor

  • 10. 
    Which of the methods of protection “d”, “e” and “m” is the best one?
    • A. 

      "d"

    • B. 

      "e"

    • C. 

      "m"

    • D. 

      None

  • 11. 
    The list below shows markings of four different products. Which product can be used in Zone 21 IIIB T180°C?
    • A. 

      II 2G Ex eb IIB T3 Gb    II 3D Ex tb IIIB T180°C Db

    • B. 

      II 2G Ex eb IIC T4 Gb    II 2D Ex tb IIIC T135°C Db

    • C. 

      II 2G Ex eb IIA T6 Gb    II 2D Ex tb IIIA T85°C Db

    • D. 

      A) and B)

  • 12. 
     A trace heating circuit is to be operated in „controlled design“ in  Zone 1 or 21 (Canada and US: Class I or II Div 2). Which of the following contact configurations is permitted (suitable contact rating given)?
    • A. 

      IV and V

    • B. 

      I, II and IV

    • C. 

      II and VI

    • D. 

      I, III and V

  • 13. 
    What is the formal prerequisite for the use of an Ex component (identified by the capital letter “U” at the end of the certificate number) in a heat tracing application?
    • A. 

      It needs to be part of a certified system

    • B. 

      The other components used along with it need to have the same method of protection

    • C. 

      It needs to be installed by personnel specifically trained by the manufacturer

    • D. 

      The intended application needs to be approved by a third party ite inspector

  • 14. 
    How must a field-installed heater be marked?
    • A. 

      A durable label with the Ex marking and all relevant electrical and temperature data of zhe installed system is to be attached to the heater or integral cold lead, close to the entry into the junction box

    • B. 

      A durable label with the Ex marking and all relevant electrical and temperature data of the installed system is to be attached to the heater close to the integral warm / cold joint

    • C. 

      In the case of self-regulating heaters, the heater print only is sufficient if it is fully visible after installation of the thermal insulation

    • D. 

      A) and C) is correct

  • 15. 
    A tender document asks for compliance with IEC 62086-1 What products can you offer?
    • A. 

      Any IECEx approved eltherm product meets that requirement, IEC 62086 has been replaced by IEC 60079-30-1.

    • B. 

      Standard IEC 62086 applies to mine, eltherm does not have products availible for that

    • C. 

      Only self-regulating heaters and their accessories can be used

    • D. 

      Only products with a valid dust marking can be used

  • 16. 
    What feature(s) does every Ex approved trace heater have?
    • A. 

      Minimum bend radius not greater than 25 mm

    • B. 

      Protective braid or equivalent conductive layer

    • C. 

      Impact resistance at room temperature of at least 4J (USA Div 1 and Canada Div 2: 7J; Canada Div 1: 14J)

    • D. 

      B) and C) is correct

  • 17. 
    A label of an installed heat tracing circuit states a maximum ambient temperature of 50°C and a maintain temperature of 80°C. Why could that be correct?
    • A. 

      The maximum ambient temperature relates to components of the circuit that are outside the thermal insulation of the heated workpiece

    • B. 

      This particular heating circuit could be a stabilized design which is suitable for an ambient temperature up to and including 50°C

    • C. 

      The circuit is designed in a way that the heater sheath temperature does not exceed 80°C if the ambient temperature is 50°C or below

    • D. 

      A) and B) is correct

  • 18. 
    What are the required test voltages and the insulation resistance readings for trace heaters?
    • A. 

      After heater installation: min 500 VDC, max. 2500 VDC; min 20 MΩ

    • B. 

      After heater installation: min 500 VDC, max. 2500 VDC (mineral insulated heaters) max. 1000VDC; min 20 MΩ

    • C. 

      After heater installation: min 500 VDC, max. 2500 VDC; min 5 MΩ

    • D. 

      After installation of the thermal insulation: min 500 VDC, max. 2500 VDC; min 5 MΩ

  • 19. 
    What statement regarding maintenance work on electric trace heaters in hazardous areas is true?
    • A. 

      When thermal insulation is removed, ignition of combustible atmospheres by the exposed trace heaters could occur

    • B. 

      Temperature sensors can be relocated as desired, when secure fastening is provided

    • C. 

      After completion of the work, a heat up to maintain temperature needs to be performed and documented

    • D. 

      If an enclosure or splice needs to be opened, he circuit has to be de-energized

  • 20. 
    A label of an installed heat tracing circuit states a maintain temperature of 120°C and a T-Class T3. Is it permitted to operate the circuit at higher maintain temperatures?
    • A. 

      Yes, because the temperature limit of T3 is 200°C and there is sufficient delta T left

    • B. 

      Yes, if the maximum process temperature specified by the end user is higher than the maintain temperature

    • C. 

      No, because the heater sheath temperature could be quite close to the temperature limit already when operated at 120°C

    • D. 

      No, unless the actual ambient temperature is in the lower half of the specified range