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 16 replies
  • Subscribers 31 subscribers
  • Views 6166 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

PME earthing to a group of static caravans TT earth required?

LittlePlumb
Can anyone give me there valuable opinions on earthing to a static-mobile home please. As per BS7671, PME earthing is not allowed to (mobile) caravans. However, does a static caravan (plumbed in and permanent with a SWA cable supplying it and no plug/socket arrangement) count as a caravan. The Static caravan is metal framed, and placed some distance from the PME source 40m or so, and the cable size is 16mm CSA 3 core, so PME (100A single phase) could be exported on the cable as its greater than 10mm CSA,

The static caravan is permanent and not quite the same as a transportable caravan, so does a TT earth need to be installed?
Parents
  • 0

    mapj1:

    The SWA armour can stay as the PME earth, so that if anyone digs it up, it trips ADS with a convincing bang, The caravans unless very old, will have RCD protection on the incomer any way, so the only need is to insulate the PME earth at the van end, and add a local earth, which assuming you can get a rod in, should be reasonably straight forward. Could even be done in an adaptable box on the outside of the van, perhaps underneath,  if there is no appetite to disturb the internal decor.

    For the opposite slant, on just how bad it can actually get, try reading this  old thread .




    Provided the SWA outer jacket is not breached, this is OK. Otherwise the separation distance from PME to the TT earth electrode below ground (10 m ... see GN 7 - derived from BS 7430 before anyone asks) is not achieved, and potential breach of ESQCR.


    Another illustration of the pain that mixing earthing systems can bring.

Reply
  • 0

    mapj1:

    The SWA armour can stay as the PME earth, so that if anyone digs it up, it trips ADS with a convincing bang, The caravans unless very old, will have RCD protection on the incomer any way, so the only need is to insulate the PME earth at the van end, and add a local earth, which assuming you can get a rod in, should be reasonably straight forward. Could even be done in an adaptable box on the outside of the van, perhaps underneath,  if there is no appetite to disturb the internal decor.

    For the opposite slant, on just how bad it can actually get, try reading this  old thread .




    Provided the SWA outer jacket is not breached, this is OK. Otherwise the separation distance from PME to the TT earth electrode below ground (10 m ... see GN 7 - derived from BS 7430 before anyone asks) is not achieved, and potential breach of ESQCR.


    Another illustration of the pain that mixing earthing systems can bring.

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