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 5 replies
  • Subscribers 32 subscribers
  • Views 1190 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

Mixed IT and TN-S Earthing Systems

Roger123
Hi, 

I'm installing Dd0yn11 transformers to supply 12-pulse VSDs; these require an IT system (I think). 

I will have other panels / motors etc. in the same area supplied from a Dyn11 (solidly earthed neutral) transformer i.e. TN-S system. 

Is there anything in BS7671 that tells me I can't have 2 earthing systems in the same area?

I would be grateful of any advice / guidance.

Thanks.
Parents
  • 0
    I guess "system earthing" (TN, TT etc) is explained (if not exactly defined in 312.2) (i.e. how the power system is earthed) while "earthing system" seems to be used consistently to mean the systems of conductors that connect exposed- and extraneous-conductive-parts to Earth. I agree some definitions would help to make it clearer though.


    Having two different systems with a common Earthing arrangement isn't uncommon - e.g. on construction sites we'd likely have a RLV transformer arranged as a TN-S system on its secondary, but it's means of Earthing will usually be the c.p.c. of the 230/400V primary circuit - which is likely part of a TT system. Ditto with some PELV systems.


      - Andy.
Reply
  • 0
    I guess "system earthing" (TN, TT etc) is explained (if not exactly defined in 312.2) (i.e. how the power system is earthed) while "earthing system" seems to be used consistently to mean the systems of conductors that connect exposed- and extraneous-conductive-parts to Earth. I agree some definitions would help to make it clearer though.


    Having two different systems with a common Earthing arrangement isn't uncommon - e.g. on construction sites we'd likely have a RLV transformer arranged as a TN-S system on its secondary, but it's means of Earthing will usually be the c.p.c. of the 230/400V primary circuit - which is likely part of a TT system. Ditto with some PELV systems.


      - Andy.
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