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Recent content by krisys

  1. krisys

    Live bus bar link in hazardous area classified as zone-0

    I am talking about a oil producing facility. I have installed a 6.6 kV junction box. As the name suggests it is a junction. So two cables are terminated to the junction box. The junction box is classified as protection Ex "e" enclosure. The strange thing happening in this case is hydrogen gas...
  2. krisys

    Can IP-66 enclosure be air tight?

    The same hydrogen generation theory holds good for power cables also. In our case aluminum is not used. These are GI armoured cables. The galvanized (GI) armours are having the zinc coating. The hydrogen generation theory for the reaction of zinc with sea water is also now a known fact. The...
  3. krisys

    Can IP-66 enclosure be air tight?

    This submarine cable is a composite cable consisting of power conductors as well as Fiber Optic (FO) section. The 96 fibers are split equally between electrical and Controls & Instrumentation application. So the FO portion is separated out in the JB and then divided equally to electrical and...
  4. krisys

    Can IP-66 enclosure be air tight?

    FreddyNurk, You are contributing a lot on the subject. Thanks for that. As you rightly said, ventilation brings its own set of problems. I have an idea. Why not do some filling inside the box. This would reduce the void space inside the JB. So there may not be a build up of H2. But please...
  5. krisys

    Can IP-66 enclosure be air tight?

    The facility might have invested few tens (if not hundreds) of million dollars for the cable procurement and installation of these submarine cables. These cable are procured from one of the best know manufacturer. Replacing the submarine cable installation of totaling about 75 kilometres at this...
  6. krisys

    Can IP-66 enclosure be air tight?

    FreddyNurk has precisely answered ppedUK’s query. The JB was meant for the installation at Oil Producing platform. So Hydrogen gas from the facility is not expected to be present. This is an unusual situation. It is an established fact that the H2 gas is entering from the cable. In one of the...
  7. krisys

    Can IP-66 enclosure be air tight?

    General: Thanks for all the valuable inputs from the distinguished panelists. Your views have reaffirmed my own understandings and enhanced the thought process. To give a perspective, I am elaborating the background and the intent as below: 6.6kV power junction boxes installed at offshore...
  8. krisys

    Can IP-66 enclosure be air tight?

    7anoter4, davidbeach - Thanks for your inputs. My query here is more to do with the Ingress Protection (IP). In terms of IP classification, whether the enclosure IP 66 is expected to be air tight?
  9. krisys

    Resilience vs Stability

    Power system stability is a recognized terminology in the context of power system analysis. Where as power system resilience is not a recognized terminology in the context of power system analysis. In the IEC world "power system resilience" is not a commonly dealt subject subject. To me it...
  10. krisys

    Lead time for 230 kV XLPE Cable

    Considering a lead time of about 6 to 9 months for the 230 kV XLPE cable with customized specification is reasonable. However, now considering the Covid-19 scenario, the variation of lead time between the vendors could be wide, depending on the lock down restrictions in the respective countries.
  11. krisys

    Can IP-66 enclosure be air tight?

    The question here is about Ingress Protection(IP) Level as per IEC standard 60529. As per this standard, I would like to know, whether the IP-66 enclosure is air tight? or Air tight IP-66 enclosure is permitted for the Hazardous area application? I have a 6.6 kV power junction box with below...
  12. krisys

    Bus bar differential protection for the 11kV power plant main switchboard using sensor type CTs

    FreddyNurk (Electrical), Thanks for your valuable feedback (positive). Yes, it is Rogowski coil. I don't know whether any one has any negative feedback on the Rogowski coil based bus bar differential protection.
  13. krisys

    Bus bar differential protection for the 11kV power plant main switchboard using sensor type CTs

    Thanks DPC. The Switchboard in question here will be from ABB, Czech Republic. Few more experiences would be appreciated.
  14. krisys

    Bus bar differential protection for the 11kV power plant main switchboard using sensor type CTs

    One of the reputed European vendor is proposing sensor type CTs for the bus bar differential protection in their new switchboard. This is the main switchboard in the power plant. However my end user has some reservations on using sensor type CTs, as these are not proven. Since this is the heart...
  15. krisys

    11 kV cable insulation rating

    Kiribanda, There is no such continuous over voltage on the bus. But the any disturbances on the power system may yield relatively higher degree of voltage disturbances. Otherwise I am not finding any technical reason to select the higher voltage grade cables. But in reality it has been the...

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