Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 20 replies
  • Subscribers 32 subscribers
  • Views 2596 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Steel Clad Building and High Voltage Overhead Cables.

Zoomup
Views invited please.


There is a modern sheet steel clad building nearby. It has what appears to be plastic covered steel sheets as exterior walls. It is used as a Scout Hut and can probably accommodate about 80 people for events. Running overhead are three high Voltage cables that feed local transformers, including the scout hut transformer which is on a pole nearby. The scout hut has two earth electrodes which connect to a part of the building and earth it. Although they are quite close together so may not really count as two in function.


Theoretically what would happen if one of the H.V. overhead cables came adrift and fell onto the roof of the building regarding risks?


This is a theoretical question relating to a real building but with a serious intention.


Thanks,


Z.


Parents
  • 0
    I would hope that the metal roof and wall cladding is bonded to earth. In such cases I would expect that contact between HV conductors and bonded metalwork would promptly operate the HV fuses or circuit breaker.

    If the metal cladding is not bonded, even accidently or fortuitously, then it would become live and a fire started. Consider that the non bonded metal work might have a resistance to earth of a few thousand ohms. That would pass about an amp, and dissipate several Kw as heat.

    This earth leakage might operate HV earth fault protection, but don't count on it.


    If it was my building, I would bond the metal cladding to both the MET and would add an earth rod.
Reply
  • 0
    I would hope that the metal roof and wall cladding is bonded to earth. In such cases I would expect that contact between HV conductors and bonded metalwork would promptly operate the HV fuses or circuit breaker.

    If the metal cladding is not bonded, even accidently or fortuitously, then it would become live and a fire started. Consider that the non bonded metal work might have a resistance to earth of a few thousand ohms. That would pass about an amp, and dissipate several Kw as heat.

    This earth leakage might operate HV earth fault protection, but don't count on it.


    If it was my building, I would bond the metal cladding to both the MET and would add an earth rod.
Children
No Data

Community Rules & Guidelines