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 10 replies
  • Subscribers 34 subscribers
  • Views 1186 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

Supplementary equipotential bonding in group 2 medical locations

Former Community Member
Former Community Member
Hi All,

I'm new here and a trainee electrical engineer. 


I am looking for pointers on how to calculate the CSA of equipotential bonding conductors in group 2 medical locations.


Having worked on site, I know that as a standard we use 4/6mm to allow us to stay within the 0.2Ohms resistance but would like to know the theory behind it so I can include this calc in my designs to prove where the result have come from when or if ever questioned.


Thanks,

Sam
Parents
  • 0
    Ok so using the rule of 16, a 6mmsq cable is 16 milliohms (0.016 ohms )  for 6m.



    soo how many metres would be 200 milliohms ?

    (well, if we pretended that the limit was a bit tighter at 160 milliohms, and that is an easier sum at ten times 16 so ten lots of 6m at 16 milliomhs each -  so 60m of wire. The limit is a bit more than 160 millioms,  so you may get a bit further than 60m. But it is a good first estimate you can do in your head without the proper tables to hand.

    As above I always like a bit in hand, as on test things tend to come out a bit 'off' , even after allowing for the last digits of the meter being as trustworthy as a fruit machine... ) 


    There will not be many rooms so large that need two or more bonds run in parallel and if they do someone will need to pop back to the truck for a second reel.... hopefully the job in a larger place will be costed accordingly.

    Mike.
Reply
  • 0
    Ok so using the rule of 16, a 6mmsq cable is 16 milliohms (0.016 ohms )  for 6m.



    soo how many metres would be 200 milliohms ?

    (well, if we pretended that the limit was a bit tighter at 160 milliohms, and that is an easier sum at ten times 16 so ten lots of 6m at 16 milliomhs each -  so 60m of wire. The limit is a bit more than 160 millioms,  so you may get a bit further than 60m. But it is a good first estimate you can do in your head without the proper tables to hand.

    As above I always like a bit in hand, as on test things tend to come out a bit 'off' , even after allowing for the last digits of the meter being as trustworthy as a fruit machine... ) 


    There will not be many rooms so large that need two or more bonds run in parallel and if they do someone will need to pop back to the truck for a second reel.... hopefully the job in a larger place will be costed accordingly.

    Mike.
Children
No Data

Community Rules & Guidelines