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 8 replies
  • Subscribers 37 subscribers
  • Views 1317 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Low insulation resistance on remote hager rcbo board and effect on upstream devices.

hertzal123

Was asked to fit an extra skt to kitchen.Old 3036 cu so fit an enclosure with 40A rcd at side of cu.

Had tested IR of ring final earlier and found to be 0.03M.The low reading was traced to a detatched

garage with a 6way hager board spurred off the ring,comprising 6no rcbos with earth leads.The "fault"

as expected cleared when the leads were disconnected.My question is:had there been a greater number

of rcbos in the board or boards, so a lower ir,would the upstream 30ma rcd trip?

Thanks for any replies.

                                                   Hz

Parents
  • 0

    I recognise that figure of 0.03Mohms. Strangely, with these RCBO units with loss of neutral I have recorded the same reading whether one or more are in circuit, hardly obeying parallel laws. 

    The connection to the earth bar remains irrespective of the position of the dolly meaning that with a neutral to earth connection in place, any legitimate line to neutral connection will cause a tumble in the line to earth insulation resistance test. 

Reply
  • 0

    I recognise that figure of 0.03Mohms. Strangely, with these RCBO units with loss of neutral I have recorded the same reading whether one or more are in circuit, hardly obeying parallel laws. 

    The connection to the earth bar remains irrespective of the position of the dolly meaning that with a neutral to earth connection in place, any legitimate line to neutral connection will cause a tumble in the line to earth insulation resistance test. 

Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines