The IET is carrying out some important updates between 17-30 April and all of our websites will be view only. For more information, read this Announcement

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 46 replies
  • Subscribers 31 subscribers
  • Views 5434 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

Loss of neutral

lyledunn
I have just been involved in a situation where temporary loss of neutral on a TNCS system caused thousands of pounds worth of damage. It seems this loss of neutral situation, either within or outside the installation, is occurring more frequently. SPDs are now commonly fitted but at DBS  and generally with a Up in the order of 860v, so giving no protection on loss of neutral in a three-phase and neutral system. Cost benefit analysis across the national spectrum might not support a compulsion but is it time designers should be raising the issue with clients and at least offering a solution. On the other hand, is there a packaged solution?
Parents
  • 0
    I have fitted capacitors N-E after a 4 pole RCD, so that if the NE voltage rises, the RCD sees the N-E current and fires and breaks everything but the CPC.

    In equipment in containers that may be  running from 'power of opportunity' with rather doubtful Zs, mains polarity and so on,  this also guards against the accidental swapping of one phase and the neutral as well, though on UK mains under and over-voltage drop out is a good thing to sense.

    Mike.
Reply
  • 0
    I have fitted capacitors N-E after a 4 pole RCD, so that if the NE voltage rises, the RCD sees the N-E current and fires and breaks everything but the CPC.

    In equipment in containers that may be  running from 'power of opportunity' with rather doubtful Zs, mains polarity and so on,  this also guards against the accidental swapping of one phase and the neutral as well, though on UK mains under and over-voltage drop out is a good thing to sense.

    Mike.
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